Heavy Topspin – The Tennis Abstract blog

Mirra Andreeva’s Many Happy Returns

*Mirra Andreeva at the 2024 Paris Olympics.*
*Credit: Like tears in rain*

Mirra Andreeva is the best teenager on the WTA tour, and it isn’t close. She’ll finish 2024 ranked 16th on the official points table, more than one hundred places ahead of her closest teenage competitor, Maya Joint. Andreeva is a year younger than Joint, and she’s two years younger than Ella Seidel, third on the under-20 list.

Players who outpace their fellow teenagers typically go on to notable careers. Here’s the list of top teenagers at the end of each season this century:

Year  Player                    Rank  
2000  Serena Williams              6  
2001  Kim Clijsters                5  
2002  Kim Clijsters                4  
2003  Vera Zvonareva              13  
2004  Maria Sharapova              4  
2005  Maria Sharapova              4  
2006  Maria Sharapova              2  
2007  Nicole Vaidisova            12  
2008  Agnieszka Radwanska         10  
2009  Caroline Wozniacki           4  
2010  Anastasia Pavlyuchenkova    21  
2011  Christina McHale            43  
2012  Sloane Stephens             38  
2013  Eugenie Bouchard            32  
2014  Madison Keys                30  
2015  Belinda Bencic              14  
2016  Daria Kasatkina             26  
2017  Catherine Bellis            46  
2018  Dayana Yastremska           58  
2019  Bianca Andreescu             5  
2020  Iga Swiatek                 17  
2021  Emma Raducanu               19  
2022  Coco Gauff                   7  
2023  Coco Gauff                   3  
2024  Mirra Andreeva              16

There’s no such thing as a can’t-miss prospect in women’s tennis, but showing up on this list gets you pretty close. Andreeva’s case is particularly extreme, because she is still just 17 years old.

In the under-18 category, the young Russian has virtually no competition. Only three other under-18s rank among the top 200, none closer than Alina Korneeva at 176th. No woman so young has finished inside the top 20 in almost two decades, going back to Nicole Vaidisova’s top-ten showing in 2006.

Here’s another way to look at what Andreeva has accomplished. With four victories to reach the Ningbo final in October, she increased her career tour-level main-draw win count to 48. Take a look at the list of all women, post-Vaidisova, to post even 30 such wins before their 18th birthday:

Wins  Player              Last Win as 17yo  
32    Victoria Azarenka         2007-07-30  
47    Caroline Wozniacki        2008-06-23  
42    Tamira Paszek             2008-09-15  
32    Donna Vekic               2014-06-23  
33    Amanda Anisimova          2019-07-29  
64    Coco Gauff                2022-03-07  
48    Mirra Andreeva            2024-10-14

Again, good company, and think of all the stars who aren’t here. You know, everybody (besides Vekic) for a decade. In this entire time span of about 17 years, Andreeva has done more at her age than anyone except Coco Gauff. The Russian might even erase that caveat. She doesn’t turn 18 until the end of April, and this year, she had won 12 matches by that time. 17 wins–enough to surpass Gauff–is hardly out of reach.

Let’s turn now to how Andreeva is achieving so much success, and why she might soon lop a digit off of her age-defying ranking.

Returns first

Forget about all this under-18 and teenager stuff for a minute. Mirra is already one of the best returners in the game. Here are the top dozen WTA tour regulars, ranked by return points won:

This isn’t a perfect measure. For one thing, Andreeva faced one of the weaker schedules of players on this list. Her median opponent was ranked 58th, compared to 30th for Iga and 42nd for Coco. It would take considerably more work to suss out whether Andreeva’s 47.3% of return points won, against her set of opponents, is better or worse than, say, Aryna Sabalenka’s 45.3% against competition nearly as stiff as Swiatek’s.

The quibbles mean that we can’t quite proclaim the Russian a top-three returner. The point, though, is that she’s in the conversation. In fact, if we narrow our view to matches against top-20 players–limiting if not eliminating the influence of each woman’s schedule–Andreeva hangs on to her position:

(We’re not talking about Iga today, but… 47% of return points won against top-20 opponents? My word.)

Where Andreeva shines even brighter is against first serves. She won first-serve return points at a higher clip than any other woman on tour this year:

Player               1st RPW%  
Mirra Andreeva          42.6%  
Coco Gauff              42.1%  
Marketa Vondrousova     40.8%  
Iga Swiatek             40.8%  
Daria Kasatkina         40.7%  
Marta Kostyuk           40.5%  
Elina Avanesyan         40.0%  
Jasmine Paolini         40.0%  
Katerina Siniakova      39.5%  
Karolina Muchova        39.5%

Put that in perspective: Andreeva wins more first-serve return points than Barbora Krejcikova (to pick one name from several) wins all return points.

Again, the Russian’s stats are influenced by her level of competition. Against top-20 opponents, Mirra falls to third place, behind Swiatek and just back of Gauff. But you get the idea. To say, “Well, actually, she’s not quite up to Gauff’s standard” is to say we’re dealing with a special player.

Precocious patience

Andreeva’s serve is good for a 17-year-old, but as we’ve seen, it’s not the side of her game that has put her in the top 20. Her returns, and by extension, her baseline play, are responsible for that.

Among top players, Mirra is currently most similar to countrywoman Daria Kasatkina. The two Russians, according to Match Charting Project data, post average rally lengths of 4.9 strokes, more than anyone else in the top 40. Both women are effective off both wings; Andreeva’s backhand is the better of the two, while Kasatkina’s forehand scores more points. The teenager is a bit more likely to force the issue: While both rank well below average in Rally Aggression Score, Mirra is closer to the norm.

A key difference shows up in their rally breakdowns. Again based on the subset of matches logged by the Match Charting Project, here are each woman’s percent of points won at various rally length categories:

Player     1-3 W%  4-6 W%  7-9 W%  10+ W%  
Andreeva    49.8%   48.6%   51.8%   53.8%  
Kasatkina   48.0%   45.6%   51.0%   52.5%

The first thing that pops out here is that Andreeva is better in every category, something that reflects both the vagaries of the uneven tennis schedule and the non-random nature of Match Charting Project samples. However you slice it, Mirra won more points, though my Elo rankings agree with the official formula that Kasatkina was the better player.

To get a better idea of what we’re looking at, let’s normalize each woman’s rally-category splits as if they won exactly half of their overall points:

Player     1-3 W%  4-6 W%  7-9 W%  10+ W%  
Andreeva    49.5%   48.3%   51.5%   53.5%  
Kasatkina   49.6%   47.1%   52.7%   54.2%

The teenager holds the edge in the 4-6-stroke category, while Kasatkina looks better in the longer rallies.

That 4-6-shot category tells us more than it lets on. Andreeva’s 48.3% (or the un-normalized 48.6%) doesn’t look very impressive. Points in this group account for one quarter of all the points she plays, and she loses more than half.

But consider her playing style. Medium-short rallies are often determined by the lingering influence of the serve: The returner might withstand a plus-one attack, only to leave a sitter for the server to put away. Or a strong return doesn’t finish the point, but the returner’s next shot–the fourth stroke of the rally–does the job. 4-6-shot rallies go disproportionately to big hitters: Aryna Sabalenka led the category this year.

For someone like Andreeva or Kasatkina, the task is to limit the damage. Get the serve back, try to neutralize the point. Place serves where aggressive returners won’t do too much damage. If a big return comes back, play the same defense that works against the serve. Kasatkina has all of those skills, but there is only so much she can do. Mirra, with her flatter strokes and somewhat bigger weapons, can keep opponents from running away with these medium-short points. She’ll lose sometimes to the likes of Sabalenka, but unless they catch her on an off day, she won’t be blown off the court.

Growth potential

If Andreeva could be characterized as a younger, somewhat more aggressive Kasatkina, that would be a pretty good compliment for a 17-year-old. But the teenager promises to become much more.

One of my favorite bits of counterintuitive tennis wisdom is that return stats rarely improve. Returning is based on a set of skills–anticipation, quickness, speed–that, on net, decline with age. Whatever tactical savvy a player picks up as she ages will, at best, cancel out the age-related decline. This isn’t an iron law, but it’s surprising how often players reach their peak return effectiveness very early in their careers.

The same is not true for the serve. 17-year-olds (or, hey, 23-year-olds) have the capacity to get stronger. Footspeed and reaction time don’t figure into the serve, so with better coaching or targeted practice (think late-career Djokovic), serve stats can improve even as the rest of a player’s game declines. A couple of examples: Maria Sakkari steadily improved her first-serve win rate from the 13th percentile to the 93rd percentile in five years. Simona Halep’s first-serve was in the top quarter of tour regulars in 2014; two years earlier, it had been one of the WTA’s worst.

The implications for Andreeva are clear. We don’t need to wishcast an improvement in her return game: She’s already one of the best returners in the game. Instead, the road to the top ten and beyond goes through her serve. Her results so far are adequate. She won 58.4% of her serve points in 2024, compared to a top-50 average of 58.7%. When we consider how much she played on clay, that number looks a bit better. On hard courts, she won more serve points than average.

Mirra, then, doesn’t face the same uphill struggle that Sakkari and Halep overcame. Her potential trajectory is more like, say, Victoria Azarenka’s. Vika arrived on the scene as a killer returner with a good-enough serve. In 2009 and 2010, she won nearly half of her return points against 58% to 59% of her service points. That combination earned her two top-ten finishes. (She was a few years older than Andreeva at that point, yet another reminder of how unique the Russian’s early success has been.)

Two years later, Azarenka boosted her rate of serve points won to 61%. Combined with the same results on return that had gotten her into the top ten, the bigger serve earned her six titles–including her first major–and the year-end number one ranking. 59% to 61% may not sound like much, but for an elite returner, that’s all it takes.

If Andreeva did the same, lifting her 58.4% serve-point win rate to 61%, she’d be the ninth-best server on tour. Remember how she’s just a tick behind Coco Gauff on return? A Vika-like serve boost would put her ahead of the American in that category, outweighing Coco’s narrow edge on return. Shorter version: She’d be a top-three player, maybe more.

None of this is guaranteed. It may not–it probably won’t!–happen right away. For every Azarenka, there’s a Nicole Vaidisova or, worse, an injury victim like Catherine Bellis. Still, few paths to the top are marked so clearly. For Mirra Andreeva, a modest, achievable set of improvements are all that stand between her and the top.

* * *

Subscribe to the blog to receive each new post by email:

How Does Jannik Sinner’s Season Stack Up?

Jannik Sinner just wrapped up a season for the ages. He won both hard-court majors, three Masters 1000s, and the Tour Finals. He led Team Italy to a Davis Cup championship and ended his campaign on a 26-set winning streak.

By November, the Italian was no longer competing against the field: He was gunning for a place in the record books. He went undefeated against players outside the top 20. Not a single player straight-setted him: He won at least one set in each of his 79 matches. Only Roger Federer, in 2005, had ever managed that.

After Sinner won the Australian Open, I wrote that Yes, Jannik Sinner Really Is This Good. Since then, he got even better. In the seven-month span ending in Melbourne, the Italian held 91.1% of his service games, a mark that not only led the tour but put him in the company of some of the greatest servers of all time. For the entire 2024 season, he upped that figure to 91.5%–including thirteen matches on clay.

He also defied the most powerful force in all of sport, regression to the mean. Sinner’s hold percentage was aided by some sterling work saving break points. He won tons of service points, of course, but he was even better facing break point. The average top-50 player is worse: Good returners generate more break points, so it’s a tough trend to defy.

In the 52 weeks ending in Melbourne, Sinner had won three percentage points more break points than overall service points. I wrote then: “I can tell you what usually happens after a season of break-point overperformance: It doesn’t last.” In the Italian’s case, though, it did. In 2024 as a whole, he won 71.1% of service points, and 73.6% of break points. He would have enjoyed a productive season without repeating his break-point overperformance, but those two-and-a-half percentage points explain much of the gap between very good and historically great.

Clubbable

Most players who serve so effectively are middling returners. The Italian has bucked that trend as well.

Late in 2023 I wrote about tennis most exclusive clubs–Alex Gruskin’s method for identifying standout players by their rankings in the hold and break percentage categories. It’s rare for anyone to crack the top ten in both. In 2023, Sinner signaled what was coming by finishing in both top fives. He ranked fifth by hold percentage and fourth by break percentage. Most seasons, that would have been enough for a year-end number one, but Novak Djokovic was even better, finishing in the top three on both sides of the ball.

Sinner, as we’ve seen, served even better this year. His 91.5% hold percentage was well clear of the pack, even with the resurgence of countryman Matteo Berrettini and increased time on tour from rocket men Ben Shelton and Giovanni Mpetshi Perricard. Last season, Djokovic led the tour by holding 88.9% of his service games. That’s impressive, especially for a guy known for other parts of his game, but it wouldn’t have cracked the 2024 top three. The Italian set a new standard.

At the same time, his return barely flagged. He fell out of the the top five by the narrowest of margins, winning nearly as many return games as he did in 2023 but falling to sixth place. Still, a “top-six club” showing is plenty rare. The only players who have posted one since 1991 (when these stats became available) are Djokovic, Nadal, Federer, and Andre Agassi. Federer only managed it once. Sinner has now done it twice.

The Italian’s return skills are even more impressive when we compare him the other season-best servers of the last thirty-plus years. The following table shows the hold-percentage leader for each year, along with his break percentage and his rank (among the ATP top 50) in that category:

Year  Player             Hold%   Brk%  Rank  
1991  Pete Sampras       87.3%  25.4%    40  
1992  Goran Ivanisevic   88.8%  20.4%    48  
1993  Pete Sampras       89.6%  27.7%    19  
1994  Pete Sampras       88.4%  29.3%    19  
1995  Pete Sampras       89.0%  26.0%    25  
1996  Pete Sampras       90.8%  20.8%    43  
1997  Greg Rusedski      91.6%  16.7%    50  
1998  Richard Krajicek   89.2%  21.4%    41  
1999  Pete Sampras       89.7%  21.7%    44  
2000  Pete Sampras       91.7%  18.4%    49  
2001  Andy Roddick       90.4%  19.7%    45  
2002  Greg Rusedski      88.5%  17.6%    48

Year  Player             Hold%   Brk%  Rank    
2003  Andy Roddick       91.5%  20.9%    43  
2004  Joachim Johansson  91.9%  14.5%    48  
2005  Andy Roddick       92.5%  20.8%    45  
2006  Andy Roddick       90.5%  22.4%    43  
2007  Ivo Karlovic       94.5%   9.8%    50  
2008  Andy Roddick       91.2%  19.2%    40  
2009  Ivo Karlovic       92.2%  10.3%    50  
2010  Andy Roddick       91.1%  17.6%    47  
2011  John Isner         90.7%  12.9%    50  
2012  Milos Raonic       92.7%  15.1%    49  
2013  Milos Raonic       91.4%  15.7%    49  
2014  John Isner         93.1%   9.3%    49  

Year  Player             Hold%   Brk%  Rank  
2015  Ivo Karlovic       95.5%   9.6%    50  
2016  John Isner         93.4%  10.9%    49  
2017  John Isner         92.9%   9.6%    50  
2018  John Isner         93.8%   9.4%    50  
2019  John Isner         94.1%   9.7%    49  
2020  Milos Raonic       93.9%  18.0%    44  
2021  John Isner         91.1%   8.8%    50  
2022  Nick Kyrgios       92.9%  19.3%    40  
2023  Novak Djokovic     88.9%  28.8%     3  
2024  Jannik Sinner      91.5%  28.3%     6

If it hadn’t been for Djokovic’s appearance at the top of last year’s list, Sinner’s 2024 campaign would be hardly recognizable. Even Pete Sampras struggled to hold on to a spot in the break-percentage top 20. Circuit-best servers simply aren’t supposed to win so many return games, yet Sinner threatens to make it the new normal.

Carrot yElo

The Italian’s 73 wins, including 18 against the top ten, took his Elo rating to new heights. He began the year with a career-high rating of 2,197, second on the circuit to Djokovic. He quickly took over the top spot, ultimately clearing the 2,300 mark with his victory at the Tour Finals.

Elo is not a perfect measure to compare players from different eras, but in my opinion, it’s the best we’ve got. It’s the basis of my Tennis 128, which Sinner will join as soon as I get around to updating the calculations. 2,300 is rarefied air: In the last half-century, he is only the twelfth player to reach that mark. With three singles victories to secure the Davis Cup, he nudged his rating up to 2,309, surpassing Mats Wilander and establishing the eleventh-highest peak since the formation of the ATP.

A stratospheric Elo is an indication of an outstanding player at the top of his game, but the metric is not designed to rate seasons. The alternative is yElo, a variation I devised for exactly this purpose. yElo works the same way as Elo does, adding or subtracting points based on wins, losses, and the quality of opposition. But unlike the more traditional measure, each player starts the season with a clean slate.

By regular Elo, Sinner holds a 150-point lead over second-place Carlos Alcaraz. By yElo, with its narrower focus, the Italian is even more dominant:

(The won-loss records are a bit different from official figures because my Elo and yElo calculations exclude matches that ended in retirement.)

The two-hundred-point gap between Sinner and Djokovic is one of the largest ever. Again going back to 1973, it ranks fourth. Only 2004 and 2006 Federer (over Lleyton Hewitt and Nadal, respectively) and 1984 John McEnroe (over Wilander) outpaced the competition by such a substantial margin.

By raw yElo, Sinner’s 2024 isn’t quite so historic. It’s the 26th best of the last half-century: An impressive feat, but not as close to the top of the list as some of the other trivia suggests. Here’s the list:

Year  Player              W-L  yElo  
1979  Bjorn Borg         84-5  2499  
1984  John McEnroe       82-3  2476  
2015  Novak Djokovic     82-6  2458  
1985  Ivan Lendl         82-7  2440  
2016  Andy Murray        78-9  2416  
2013  Novak Djokovic     74-9  2408  
1976  Jimmy Connors      97-7  2406  
1977  Bjorn Borg         78-6  2403  
1977  Guillermo Vilas  133-13  2401  
2006  Roger Federer      91-5  2399  
1980  Bjorn Borg         70-5  2395  
1981  Ivan Lendl        96-12  2383  
1987  Ivan Lendl         73-7  2381  
1982  Ivan Lendl        105-9  2380  
1978  Jimmy Connors      66-5  2379  

Year  Player              W-L  yElo  
2013  Rafael Nadal       74-7  2373  
1986  Ivan Lendl         74-6  2369  
2011  Novak Djokovic     63-4  2367  
2005  Roger Federer      80-4  2364  
2014  Novak Djokovic     61-8  2363  
2012  Novak Djokovic    73-12  2360  
1978  Bjorn Borg         79-6  2359  
2008  Rafael Nadal      81-10  2352  
1986  Boris Becker      69-13  2347  
1982  John McEnroe       71-9  2341  
2024  Jannik Sinner      72-6  2339  
1983  Mats Wilander     80-11  2338  
1974  Jimmy Connors      94-5  2332  
1989  Boris Becker       64-8  2329  
2015  Roger Federer     62-11  2329

One factor holding back Jannik’s 2024 is the number of matches played. Elo, in part, reflects the confidence we have in a rating. Winning 90% of 100 matches (or almost 150, in the case of Vilas) gives us more confidence in an assessment than 90% of 80 matches.

Another issue is that Elo has opinions about strong and weak eras. Going 70-5 in 1980 doesn’t look much different than 72-6 today, but Elo considers Bjorn Borg’s peers to have been stronger than Sinner’s. If Sinner and Alcaraz continue to improve and a couple of their peers emerge as superstars in their own right, then a 72-6 season might rank much higher.

The asphalt jungle

A couple of months ago, pundits started mulling where Sinner’s 2024 stood among the greatest hard-court seasons of all time. Since then, he piled on so many more wins that the qualifier wasn’t needed. Yet it remains a valid question.

The Italian’s highlights came almost entirely on hard courts. He won 53 of 56 matches, 42 of them in straight sets. He’s plenty skilled on natural surfaces, but given a predictable bounce and conditions that emphasize his power and penetration, opponents don’t stand a chance.

I don’t publish surface-specific yElo ratings, because they have limited usefulness for much of the year. For our purposes, though, hard-court yElo–same algorithm, limited to matches on one surface–is just the ticket. By this measure, Sinner’s 2024 is the eighth-best of all time:

Year  Player          Hard W-L  Hard yElo  
2015  Novak Djokovic      59-5       2426  
2013  Novak Djokovic      53-5       2413  
2012  Novak Djokovic      48-5       2377  
2005  Roger Federer       49-1       2374  
2006  Roger Federer       59-2       2373  
1995  Andre Agassi        52-3       2370  
2016  Andy Murray         48-6       2363  
2024  Jannik Sinner       52-3       2353  
2010  Roger Federer       45-7       2338  
2014  Novak Djokovic      40-6       2334 

Year  Player          Hard W-L  Hard yElo   
2014  Roger Federer       56-7       2333  
1985  Ivan Lendl          29-3       2332  
1987  Ivan Lendl          33-2       2325  
1996  Pete Sampras        46-4       2319  
2015  Roger Federer       38-6       2318  
1981  Ivan Lendl          41-3       2317  
2011  Roger Federer       45-7       2314  
2009  Novak Djokovic     53-10       2309  
1985  John McEnroe        25-1       2309  
1986  Ivan Lendl          30-2       2298

So, um, peak Djokovic was pretty good, huh?

Even though Elo doesn’t hold the rest of the 2024 field in particularly high regard, Sinner’s season was so dominant that he does well by this measure. A year that would rate as Djokovic’s fourth-best, Federer’s third, or Agassi’s second, is truly something worth celebrating.

The Italian still has some ground to cover before he challenges Novak, Roger, and the rest for all-time hard-court dominance. But he has already upped the standard for the 2020s and posted one of the most remarkable two-year spans in the game’s history. Sinner has built an enormous gap between himself and the field, and it is increasingly difficult to see how his peers will close it.

* *

Subscribe to the blog to receive each new post by email:

Jasmine Paolini’s High-Wire Act

*Jasmine Paolini at the 2022 Transylvania Open. Credit: Nuta Lucian*

There are unorthodox aging curves, and then there’s whatever the hell Jasmine Paolini is doing right now. The best women tennis players tend to make their presence known in their late teens. I wrote earlier this year about the “improbable rise” of 22-year-old Emma Navarro.

Paolini is 28.

When Paolini was the age that Coco Gauff is now, she was ranked just inside the top 300, fresh off a first-round loss at an ITF $25K in Bulgaria. When she was the age that Iga Swiatek is now, she had finally cracked the top 150, about to head to Wimbledon qualifying. (She lost in the first round there, too.) When she was the age that Aryna Sabalenka is now, she had just stumbled through a four-match losing streak to the likes of Jil Teichmann and Irina-Camelia Begu that knocked her out of the top 50.

Just 16 months ago, Paolini was once again outside the top 50. For a five-foot, four-inch counterpuncher with no obvious weapons, she had achieved a great deal. There was little reason, though, to think she could climb much higher. Her peers were getting bigger, the game was becoming ever more aggressive, and she was reaching the age at which WTA stars begin to think about what else life might hold for them.

Then she started winning.

Since leaving Wimbledon last year, the Italian has won 66 of 99 matches, including two major semi-finals and five top-ten scalps. She picked up her first 1000-level title and made four other finals. Yesterday, she led Team Italy to a Billie Jean King Cup crown, starring in both singles and doubles en route to the championship. Her ranking is up to an astonishing 4th in the world. As if that weren’t enough, she’s in the top ten in doubles.

None of this was supposed to happen. Paolini’s late-2023 surge to the top 30 was one thing; what has happened since simply defies belief. How has she managed it? Is it a fluke, or will we see the Italian at the 2025 year-end championships as well?

Opportunistic effects

First, a bit of a caveat. Paolini, like Taylor Fritz, has played the official ranking system like a Stradivarius. She reached only three finals in 2024, yet two of them were slams. The other was a 1000. She earned huge chunks of points for a semi-final defeat of Mirra Andreeva at Roland Garros, a semi-final squeaker against Donna Vekic at Wimbledon, and a Dubai title that didn’t require her to face a top-ten opponent.

None of this is meant to take away from Paolini’s accomplishment. She beat the players in front of her, and in the case of Andreeva, she did so in emphatic fashion. The point is that her top-four finish has more to do with good timing than consistently dominant play.

My Elo ratings offer a second opinion, using an algorithm based on the quality of her opponents, rather than the venue and round of each match. By Elo, she stands in 9th place, just ahead of Madison Keys and Diana Shnaider, well back of Jessica Pegula and Elena Rybakina. Still a very good season, if a bit less astounding.

Even more revisionist is the total-points-won leaderboard. Going into the BJK Cup Finals, Paolini had won 51.8% of her total points this season. That’s a respectable rate, especially for someone who hovered in the 50% range for most of her tour-level career. But it is not typically top-five, or even top-ten material:

By this metric, the Italian stands in 19th place among the WTA top 50, behind a handful of players who didn’t even crack the official top 20. That doesn’t really mean she’s the 19th best player on tour: She faced one of the toughest schedules of anyone. Much as I love both Yulia Putintseva and counterintuitive arguments, I’m not going to try to convince you that Putintseva had the better season.

Still, Paolini’s position on the TPW list tells us something about how she won her matches. She didn’t lose many blowouts, but she didn’t win many, either. (She certainly didn’t get in the habit of spanking opponents like Swiatek and Sabalenka do.) Ten of her wins required a third set. Two victories–including the Wimbledon semi-final–came despite losing more points than she won.

The margins were not so narrow that we can ascribe the Italian’s breakout to luck. (Though the Vekic match could have gone either way, to say the least.) But this is the high-wire act that took Paolini to the top. She doesn’t have the tools to bludgeon her opponents. She has done a lot of things right to win 42 matches this year. To keep winning at a two-of-three clip, she’ll need to continue executing the new game plan to near-perfection.

The new game plan

It’s a bit tricky to isolate the key changes in Paolini’s approach, because–like Qinwen Zheng–she’s doing almost everything better than she did before the surge. That said, a few things stand out.

Check out the Italian’s breakdown of points won by rally length (in Match Charting Project-logged matches) before this season, compared with her performance this year:

Span     1-3 W%  4-6 W%  7-9 W%  10+ W%  
2016-23   49.1%   46.5%   51.0%   49.4%  
2024      49.8%   54.3%   56.6%   49.1%

Paolini’s improvement in 7- to 9-stroke rallies is significant, and her gain in the 4- to 6-shot category is enormous. In very short points and very long ones, little has changed.

Especially in the categories of shorter points, we need to keep in mind what these win rates measure. It’s tempting to think of a prototypical short point, then imagine Paolini, instead of her opponent, winning it. But the length of a given point is not handed down to us by God. When someone like Paolini starts winning more shorter points, it’s because she is ending them before they become long points, and/or she is preventing her opponents from ending points quickly.

The Italian can hardly stack up one-shot points (unreturned serves), and she can’t even reliably put away plus-ones–though she is doing that more than she used to. Instead, like the expert doubles player she has become, she can structure points that inch closer and closer to a point-ending opportunity. Call it plus-two tennis, aggressive point construction for undersized counterpunchers.

The plus-two forehand

Tactics are one thing; Paolini is a top-ten player because she has executed them so well. Her forehand is a big reason why.

She is ending points with her forehand at a much better clip than she did before the calendar flipped to 2024, and her inside-out forehand has seen particular improvement:

Span     FH Wnr%  DTL Wnr%  IO Wnr%  FHP/100  
2016-23    11.7%     17.7%     6.2%      2.9  
2024       17.5%     25.2%    13.3%     10.2

Here, “winners” refer to both clean winners and shots that induce forced errors. Through 2023, Paolini’s forehand winner/forced error rate of less than 12% put her in the bottom quarter of tour regulars. 17.5% moves her to the top third, not far behind Swiatek and Keys. The same stat for inside-out forehands (IO Wnr%) doesn’t put her in quite the same company, but it is an even better reflection of the tactical shift. Before, the Italian rarely used that shot as an offensive weapon; now it is a regular part of the arsenal.

The bottom line is reflected in the Forehand Potency (FHP/100) numbers. The number of points Paolini earns with her forehand more than tripled from previous seasons to 2024. That doesn’t quite account for the entire shift from a top-50 player to a top-fiver, but it explains a whole lot.

And the no-fearhand

One side effect of the Italian’s forehand-centered strategy is that she is less afraid of other players’ forehands.

Again, Paolini is doing just about everything better. For instance, 22% of her first serves went unreturned in 2024, compared with 20% in the past. Nice little boost, but not something you would notice by watching a couple of matches. A bigger shift is where she puts the first serves:

Span     1st Unret%  <=3 W%  RiP W%  D Wide%  A Wide%  
2016-23       20.2%   28.1%   48.3%    25.0%    45.7%  
2024          21.8%   34.8%   53.4%    37.4%    44.8%

Check out the rate at which she is hitting deuce-court first serves wide (D Wide%). 25% to 37% is a massive change, and one that would be dangerous for a different sort of player. In the deuce court, the down-the-tee serve is the conservative one: It goes to the backhand of a right-handed returner, and since it lands in the middle of the court, the returner doesn't have any sharp angles to exploit. The wide serve is the opposite, feeding forehands to opponents like Sabalenka, Rybakina, or Zheng along with the angles necessary to turn them into winners.

What Paolini knows--again, like a savvy doubles player--is that most players will fail to convert the majority of those opportunities, even if they occasionally smack a highlight-reel return winner. The Italian didn't crack the top five by running the table against the elite. Most of her 42 wins came against the next rung of competitors, women who are often held back by inconsistency. Paolini pushed them off the court, giving the choice of either going big (and frequently missing), or sending back a shot that she could handle with her own (improved!) forehand.

All those deuce-court wide serves explain how Paolini picked up so many more plus-one winners (the <=3 W% column) and converted so many in-play returns overall (RiP W%). Every individual wide serve is a gamble, but the Italian has discovered that, on net, they pay off.

The way forward

I'm a bit surprised to find myself concluding that, yes, Paolini might just maintain this level. The odds are heavily against another top-five finish. That was a quirk of her draws and well-timed (probably accidental!) peaks. But 52% of total points? A single-digit year-end ranking? Maybe!

Once I began thinking of the Italian's singles play in terms of doubles strategy, it all clicked. Her anticipation is outstanding--and like everything else, it is better than it was last year. She often wins points without working particularly hard. She's in the right place to end the point on the fifth or sixth shot of the rally. (That place is increasingly at the net. She came to net more in 2024, and she won more of those points than before, too.) Anticipation isn't a skill that will deteriorate with age, nor is it one that opponents can neutralize.

Paolini's new point-shortening, forehand-smacking, deuce-court-serving tactics aren't going to earn her many big upsets, just as they haven't so far. The strongest players--not coincidentally, often the ones with the most fearsome forehands--are the ones in the best position to take advantage the wide deuce-court serves and force the Italian both to move off the baseline and rely more on the backhand.

But a top-ten season doesn't require a pile of top-ten victories. Paolini was 3-6 against that group this year, and that included one win against a fading Ons Jabeur and another in Riyadh against a rusty Rybakina. The Italian's finish owed much more to her 38-15 record against everyone else. Despite the improbability of a top-ten debut at age 28, Paolini has built a game capable of repeating the feat in 2025.

* *

Subscribe to the blog to receive each new post by email:

The Riddle of the Ruud-Rublev Reversal

The story of the the 2024 ATP Tour Finals was the dominance of Jannik Sinner. I’ll refer you to what I wrote after the Australian Open: Yes, Jannik Sinner Really Is This Good. He just passed the 2,300 Elo threshold, becoming only the 12th man since Rod Laver to do so. When I update the Tennis 128 in a few weeks, he’ll be on it.

For all that, I’m preoccupied with something else. On the final day of round robin play, Casper Ruud beat Andrey Rublev to secure a place in the semi-finals. It was their eighth meeting and the Norwegian’s third victory:

Notice anything odd? Take away the unfinished Australian Open tilt, and the head-to-head breaks down precisely on surface lines. Rublev has won all four encounters on clay, while Ruud has run the table on hard courts. Not just any hard courts: indoors, at the Tour Finals.

We can look to external factors to explain some of the individual results. Casper had more at stake on Friday than the Russian did, with a chance to qualify for the final four. Rublev is older and broke through correspondingly earlier, so he was the natural favorite in their early meetings. Injuries and illness may have influenced another outcome or two, even aside from the retirement in Melbourne.

Still: 0-3 in completed matches for the ball-basher on hard courts, and 0-4 for the Roland Garros finalist on clay. Something’s going on here.

Not so fast

Rublev, to be fair, is hardly a fast-court specialist. His first tour-level title came on dirt in Umag, and he picked up a Masters crown last year in Monte Carlo, on one of the circuit’s slowest surfaces. The Russian’s forehand is a weapon in any conditions, and slow courts can disguise some of his weaknesses.

On the other hand, however much Rublev likes the dirt, Ruud likes it more. Earlier this year, I quantified the notion of “surface sensitivity,” the degree to which a player’s results are influenced by court speed. Rublev scored at -2.2, indicating that he does better on slower surfaces, a bit more so than the typical tour regular. Casper was considerably further down the list, at -5.0. The rating tells us that he’s more receptive to slow courts than Pablo Carreno Busta or Jaume Munar. He’s grades about the same as Diego Schwartzman.

Maybe the oddball head-to-head is a quirk of when the pair have met? Not all hard courts play fast, and not all clay behaves like the crushed brick at Roland Garros. Here are the venues for the seven completed meetings, along with my ace-based surface speed rating for each. Ratings above 1 are faster than average, below 1 are slower:

Year  Tournament   Winner  Speed  
2024  Tour Finals  Ruud     1.36  
2023  Bastad       Rublev   0.86  
2022  Tour Finals  Ruud     1.50  
2021  Tour Finals  Ruud     1.51  
2021  Monte Carlo  Rublev   0.54  
2020  Hamburg      Rublev   0.52  
2019  Hamburg      Rublev   0.74

Hypothesis denied! The 2021 and 2022 Tour Finals were the fastest conditions of their respective years, while Monte Carlo was the slowest of the entire 2021 season. Last year’s Bastad surface was fairly neutral for a clay court, but the rest of the Ruud-Rublev showdowns took place on fast hard courts or slow clay.

We could always mark down a string of seven surface-confounding results to luck, especially when both players are capable in all conditions. But it would be far more satisfying to find an explanation that tells us something about the players and their particular skills.

Stoppable

We don’t have to look far. Here are Casper’s win rates on first and second serve points against Rublev, separated by surface:

Surface  1st W%  2nd W%  
Clay      56.8%   48.4%  
Hard      72.7%   50.7%

Everybody wins fewer first serve points on clay than on hard courts, but not like this. The average gap for top-50 players in 2024 is four percentage points–not sixteen. At tour level against the entire field, Ruud has shown an even smaller difference, winning 73.1% of hard-court first-serve points against 71.2% of those on clay.

Rublev is not a brilliant returner. He’s a serviceable one with tactics to match. He often struggles to get first serves back in play. On second serve, he’s unafraid to unleash his weapons, accepting some errors in exchange for tilting other points in his favor. On clay, he’s able to turn a few more first serves into rally openers. In 2024, his gap between clay and hard-court first-serve return points won was bigger than average. But not nearly as wide as it is against Casper.

When it works…

Ruud, like many men who have developed into strong clay-courters, doesn’t have a monster serve. He can place it, he can disguise it, and he knows how to play behind it. On a fast hard court, those skills–combined with a bit more risk-taking–can result in numbers that look more like those of a big server. Against Rublev last week, he won just shy of 80% of his serve points, supported by 15 aces.

When the Norwegian is hitting corners and the ball is skimming off a court like the speedy one in Turin, Rublev is helpless. Over his career, according to the nearly 200 matches logged by the Match Charting Project, he puts 58% of first serves back in play. Against Casper on Friday, he didn’t manage 50%–a repeat of his performance on the same court two years earlier.

Rublev’s first-serve-return struggles on hard court contrast with how he feasts on Ruud’s serve on clay. The next table shows the rate at which the Russian puts Casper’s first serves in play, as well as his win percentage when he does so:

Match                Result  1st: RiP%  RiP W%  
2024 Tour Finals RR       L      46.9%   43.3%  
2023 Bastad F             W      64.6%   61.3%  
2022 Tour Finals SF       L      45.7%   50.0%  
2021 Tour Finals RR       L      67.5%   51.9%  
2021 Monte Carlo SF       W      84.4%   59.3%  
2020 Hamburg SF           W      91.4%   59.4%

The exception to the rule here is the 2021 Tour Finals match, which ended in a third-set tiebreak. It was the closest either man has come to securing one of the matches he “should” have won. Rublev won 52.9% of total points, but Ruud served his way out of just enough jams to come through.

On the very slow Monte Carlo and Hamburg courts, Rublev’s ability to handle the Norwegian’s first serve meant that Ruud was left with no edge whatsoever. Casper might be the superior baseliner, but he started too many points at a disadvantage. The picture might look different if they played on slow clay today, since Ruud is stronger and tactically savvier on serve. But I imagine it would still be a struggle, one in which few of Casper’s service games would sail by quickly.

Pundits like to say that tennis is a game of matchups. They often overstate their case: The better player (by ranking, or Elo rating, or whatever) usually wins. When they don’t, it isn’t always because of some quirk in the head-to-head. With Rublev and Ruud, though, such a quirk dictates the results. Few men are able to erase Rublev’s advantage on a hard court as much as the Norwegian can. Casper’s first serve is rarely so ineffectual as when the Russian is waiting for it on dirt. Ruud is set for another big European clay swing next year–so long as his buddy Andrey lands in the other half of the draw.

* * *

Subscribe to the blog to receive each new post by email:

The Newly Opportunistic Taylor Fritz

*Taylor Fritz at the 2023 US Open. Credit: Andy M. Wang*

Taylor Fritz has been remarkably consistent over the last three seasons. He ended the 2022 campaign ranked 9th, finished last year 10th, and enters this week’s Tour Finals in 5th place, with a chance to overtake Daniil Medvedev for a spot in the top four.

Take a look at his top-line statistics for 2022, 2023, and 2024. They’re sorted by total points won (TPW). Can you tell which one belongs to his career-best current season?

Year   Win%   1st%   2nd%    RPW    TPW  
???   68.8%  78.4%  54.3%  37.7%  53.0%  
???   70.4%  78.3%  55.8%  36.2%  52.8%  
???   69.1%  76.4%  52.6%  38.2%  52.4%

You might be tempted to go with the first row, since he won the most points then. But the margin is small, and he won matches at a better clip in the second. Wait, though: He snagged the most return points in the third season, and more breaks of serve are particularly crucial for a player hovering in the 36% to 38% range.

I won’t leave you hanging. The second line belongs to 2024. Here are the three stat lines, now sorted by season:

Year   Win%   1st%   2nd%    RPW    TPW  
2024  70.4%  78.3%  55.8%  36.2%  52.8%  
2023  68.8%  78.4%  54.3%  37.7%  53.0%  
2022  69.1%  76.4%  52.6%  38.2%  52.4%

The 27-year-old American is clearly doing something right that isn’t captured by the usual stats. 10th to 5th is a major move. Last year he didn’t even qualify for the Tour Finals. After beating Medvedev yesterday, he’s one win away from a probable berth in the semis. What’s going on here?

All the right matches

The official ranking system ensures that tournaments and matches are very much unequal. When Fritz beat Frances Tiafoe in the Acapulco quarter-finals last year, he gained an additional 90 points for his semi-final showing. When he slipped past Tiafoe in this year’s US Open for a place in the championship match, he earned a whopping 480 points.

I could just about stop here. 480 points is the difference between Fritz’s current point total and 8th place. A slightly bigger difference of 560 points would knock him down to 10th, and he’d be hanging around Turin this week as an alternate. His stats would barely change, but the story of his season would be very different.

It’s not just the Tiafoe match; it’s more than the US Open final. 2024 was the first year that Fritz lived up to expectations at the slams in general. Here are his grand-slam win totals back to 2018:

Year  Wins                  
2024    17                  
2023     8                  
2022     8                  
2021     6                  
2020     6  * no Wimbledon  
2019     4                  
2018     4

No top tenner would be happy with just eight wins at majors. Simply reaching the fourth round at each slam adds up to 12. In 2022, Fritz lost five-setters to Stefanos Tsitsipas and Rafael Nadal, then fell to a streaking Brandon Holt in Flushing. Last year, he suffered two second-round exits. Both five-setters, the losses came against Alexei Popyrin in Australia and Mikael Ymer at Wimbledon.

When the 2024 season kicked off, Fritz had just two major quarter-finals to his name. His career record in five-setters was 8-10.

Since then, the American has reached three more quarters (including the US Open final run). He won four five-setters against just one defeat. He avenged the Melbourne loss to Tsitsipas and twice upset Alexander Zverev, a player who had beaten him in five of eight previous meetings.

The re-balancing

The odd thing about Fritz’s season is that his slam success has been offset by weaker results elsewhere. Returning to the observation I started with: He won nine more matches at majors in 2024 than in 2023, but his winning percentage barely budged. Instead of losing to Ymer or Holt on a big stage, he fell to Matteo Arnaldi in Acapulco, Thiago Seyboth Wild in Miami, Alex Michelsen in Geneva, and more.

It was a smart trade, though it was surely not a premeditated one. You can train with the majors in mind, but you can hardly punt an early-round match at a 250 with any kind of hope that it will result in a quarter-final victory at the next slam.

There’s another category, though, in which Fritz may have used stronger tactics to get better “luck.” Here are the American’s tiebreak records since 2021:

Year  TB W-L    TB%  
2024   21-11  65.6%  
2023   25-17  59.5%  
2022   24-20  54.5%  
2021   20-15  57.1%

The 2023 mark of 59% is about where Fritz should be, based on the rate at which he normally wins serve and return points, combined with the matches in which he finds himself in tiebreaks. 2024 was the first season he beat tiebreak expectations by a non-negligible margin.

This could be luck. Tiebreak records fluctuate, and very few players sustain records above or below expectations for long. Still, the American might have figured something out. In the sample of 2024 matches logged by the Match Charting Project (plus several others from grand slams), Fritz is serving way better in tiebreaks than he has in the past:

Year  TB SPW  
2024   80.3%  
2023   65.6%  
2022   70.9%  
2021   65.0%

80% is Isner territory. In the improbable event that Fritz can sustain these kinds of numbers, coupled with a solid return-points-won rate around 38%, he should be winning even more tiebreaks than he already does.

I don’t want to overemphasize tiebreaks: After all, his 21-11 record is only one or two tiebreaks better than it “should” be. On the other hand, it’s easy to scan through Fritz’s career results–including those at majors–and see how one or two tiebreaks could change the story. He took a first-set tiebreak from Tsitsipas in Melbourne this year. He split two against Zverev at Wimbledon, then took two of two from the German in New York. Take one of those away–just one!–and again, he might be watching the Tour Finals from the sidelines.

Zverev tolerance

Regardless of whether tiebreak luck played a role, Fritz’s two major victories over Zverev helped to define his season. Neither pre-match betting odds nor my Elo ratings predicted an American victory on either occasion.

Both Fritz and Zverev are tall guys with big serves; either one can put away a service game with four quick strikes. One key difference between them is that Zverev is more patient, comfortable playing long points from the baseline. This isn’t necessarily an asset: It isn’t always in the German’s interest to let matches go that way. But if you’re going to pick one of these two guys to play points from the baseline, it’s pretty clearly Zverev.

In the US Open quarter-final, though, 39 points went ten strokes or longer. Fritz won 20 of them. In the fourth-set tiebreak, three and half hours into the battle, the American won two of two: a 24-stroke grinder that Fritz finished at the net, then a 12-shotter on match point that Zverev squandered with a unforced forehand error.

Two lessons jump out. First, the American can hold his own from the backcourt with one of the best baseliners in the game, at least on a hard court. Second, that skill doesn’t seem to fade with fatigue, something that might have caused Fritz’s five-set struggles in the past.

A third takeaway may be even more important. Instead of the numerator–20 points won–consider the denominator: 39 points played. The first time Fritz and Zverev met at a major, at Wimbledon back in 2018, barely half as many points lasted so long, even though the match itself was longer. Yes, the surface kept that number down, but not by a factor of two. At Washington early in Fritz’s career, on a surface more like that in Flushing, the two men played an entire match with just one rally that reached ten strokes.

In that 2018 Wimbledon meeting, Fritz held his own in the long rallies, winning 9 of 21. The problem was his rush to avoid them. He committed 56 unforced errors to the German’s 36.

Zverev keeps his unforced error rates down because he is willing to wait. He forces opponents to take risks unless they want to spend all day grinding out baseline battles. Most players in the Fritz mold–including Fritz himself, in the past–opt to take their chances. They usually lose, which is why Zverev is ranked second in the world. The American has steadily improved his groundstrokes and his fitness to the point that he doesn’t need to take low-percentage big swings. It’s no guarantee of victory–after all, Fritz won just 50.9% of points in the Flushing four-setter–but it’s a better bet than the alternative.

Let’s play ten

There’s a wider lesson here, and not just for Taylor Fritz. We tend to think of long-rally proficiency as a clear-cut skill. Yes, some players are better at it than others, but not by a wide margin.

Here are the long-rally (10+ shots) winning percentages for the ATP top ten, based on Match Charting Project data for the last 52 weeks:

Player            10+ W%  
Alex de Minaur     57.4%  
Carlos Alcaraz     57.1%  
Jannik Sinner      55.8%  
Daniil Medvedev    55.0%  
Grigor Dimitrov    54.2%  
Novak Djokovic     52.8%  
Andrey Rublev      51.8%  
Casper Ruud        50.2%  
Alexander Zverev   50.2%  
Taylor Fritz       46.8%

Before I studied this, I would’ve expected considerably more dispersion. While every edge counts, this one is not as crucial as it gets credit for. Fewer than one in ten points reach the long-rally threshold, so even the most extreme gaps–like that between Fritz and de Minaur here–would determine the outcome of only the closest matches.

More important, I suspect, is willingness to play these points. Fritz is never going to crack the top half of a list like this. He has–to his credit–maxed out the rally tolerance that his size and physical gifts will grant him. Still, a 47% chance of winning a protracted point is better than his odds after belting a low-percentage salvo to avoid the battle altogether.

Players who serve as effectively as Fritz does tend to be considerably less sturdy from the baseline. Pros with his (adequate if not world-beating) groundstrokes are often less inclined to rely on them. One-dimensional big servers almost never reach the top five. Yet Fritz, combining his primary weapon with a tactical savvy that allows him to maximize the rest of his assets, has done exactly that.

* * *

Subscribe to the blog to receive each new post by email:

Qinwen Zheng’s Rising Tide

Since a first-round exit to Lulu Sun at Wimbledon this year, Qinwen Zheng has transformed herself from a rising prospect to a force at the top of the women’s game. The 22-year-old has won 30 of 35 matches, picking up three titles including an Olympic gold. In her first appearance at the tour finals this week, she has defeated two top-five players and earned a place in the semi-finals.

Zheng currently sits at 7th in the official rankings, equal to her career best. Her performance in Riyadh will move her up to at least sixth. Elo, a leading indicator as usual, already considers her the third-best player in the world, behind only Aryna Sabalenka and Iga Swiatek. The Chinese player is riding an astonishing 30-2 streak against everyone not named Sabalenka, so it’s hard to argue.

What has changed? Zheng has long been ticketed for big things. Her January run to the the Australian Open final indicated that she was reaching her potential. But she made only two quarter-finals in the next ten events, losing both. There were clear weaknesses in her game then. Has Qinwen 2.0 plugged those gaps?

Lifting all metrics

When I last wrote about Zheng, I referred to her serve as “under construction.” Her first serves were (and are) among the very best in the game. But she missed often, and her second serve was below average for a top-50 player.

I proposed an admittedly theoretical solution, that she could play somewhat more conservatively on the first serve, still winning plenty of points. Then she could go (relatively) bigger on seconds, trading a few more double faults for better results. The bottom line, at least according to the algorithm, was that the shift would increase her serve points won from a good 60.1% to a great 61.7%.

She hasn’t done any of that. Yet since leaving Wimbledon, she has won 63.3% of service points. That’s better than the full-season mark of anyone except Swiatek.

Qinwen found a blunter solution: She just got better at everything. Here’s an overview of her serve and return results for the two halves of 2024–up to and after Wimbledon–as well as her hard court results in 2023:

Time Span        W-L  1stIn%  1stW%  2ndW%    SPW    RPW  
2023 Hard      26-12   51.9%  74.3%  45.7%  60.5%  43.6%  
2024 1st half  19-12   51.5%  74.9%  45.5%  60.6%  42.9%  
2024 2nd half   30-5   53.8%  76.5%  47.9%  63.3%  45.9%

First serves in? Up two percentage points. First serves won? Two points. Second serves won? Two points. Return points won? Three points from the first half of 2024 to the second, even though the average surface is faster.

These are enormous shifts. 54% of first serves in still leaves her near the bottom of the table, but moving from 60.6% to 63.3% serve points won is the difference between the edge of the top ten and, as noted, number two. Key to the move is the rate of second serves won, which improved from the bottom third of tour players to the top half. On return, 42.9% to 45.9% is a jump from the bottom quartile of tour regulars to the top.

In short, Zheng went from having weaknesses to not having weaknesses. It’s never easy to divvy up the credit between player and coach, but if Pere Riba doesn’t win coach of the year, we might as well quit giving out the award.

Ratioing the tour

One of the goals of my research is to help us be more specific when we analyze players. Zheng’s various points-won rates give us a clearer view than just going goggle-eyed at a 30-5 record. But it’s tough to pinpoint a player’s improvement when she suddenly does everything better.

Qinwen’s rates of winners and unforced errors leave us in the same conundrum: She’s just gotten better by every conceivable metric. Still, I have to share. Sometimes it’s worth going goggle-eyed.

I have winner and unforced error stats for a limited subset of matches–77, in Zheng’s case–from a combination of grand slam data and the Match Charting Project. For the 58 matches through the loss at Wimbledon, she hit winners on 16.9% of points, versus UFEs on 19.2%. That works out to a ratio of 0.88, which is quite good. Commentators like to point to a 1:1 ratio as a goal, but that’s relatively rare on the women’s tour. 0.85 is usually sufficient to win a match.

Since July, the Chinese player’s W/UFE rates have basically flipped. In 18 matches worth of data, she’s hit winners on 19.3% of points, against a 17.0% unforced error rate. Those numbers are good for a ratio of 1.14. Here’s a complete list of the women who have posted better ratios this year:

1. Aryna Sabalenka

That’s it. With more complete data, it’s possible that Zheng would outscore Sabalenka, too. We have W/UFE for four of Qinwen’s five second-half losses, but only 14 of 30 wins. The sample is probably a bit biased against her.

The backhand complement

When I wrote about Zheng in January, her forehand–assessed by my Forehand Potency (FHP) metric–already ranked in the top ten among tour regulars. Her backhand remained a question mark.

If there are any specifics we can glean about the 22-year-old’s improvement, it is here. Until the beginning of this season, her backhand was, more or less, a neutral shot. The Backhand Potency (BHP) stat measures how often a shot ends the point for or against the player, as well as how often it sets up a point-ending shot shortly thereafter. In 2024, Qinwen’s backhand has been five times more effective that it was before:

Time Span  BHP/100  Negative Matches  
2021-23        1.2          13 of 32  
2024           6.3           6 of 34

In the past, the Zheng backhand cost her points–that is, it rated a negative BHP–nearly half the time, in 13 of 32 charted matches. This year, it has rarely done so. While BHP per 100 backhands (BHP/100) can’t be directly converted to a number of points per match, it’s safe to estimate that her backhand is now worth at least two or three points per match that she wasn’t winning before.

A few points per contest are enough to separate a good player from a great one. The backhand alone accounts for a big chunk of the gap between early Qinwen and the current unbeatable model.

We can even see the connection between BHP and return points won. This year, Zheng has gotten more returns in play: about one percentage point more, despite the fact that she has played Sabalenka so many times. Often, pros increase that metric by playing more conservatively. They send more balls back but do so weakly, losing most of those points. The Chinese woman, on the other hand, has also improved her win rate when she puts the return in play. That number–at least in the sample of charted matches–has risen from 53.8% to 56.8%.

Return stats aren’t all about the backhand, but when someone has as dangerous of a forehand as Zheng does, opponents make the return as much about the backhand as they can. No longer anything resembling a servebot, Qinwen threatens in more and more return games. Last year, she earned a break point in 43% of (charted) return games; this year, she is up to 49%.

Up and to the right

At the risk of repeating myself: Every trendline for the 22-year-old is headed in the right direction.

Zheng has never beaten Sabalenka, but after losing 6-1, 6-2 at the US Open, she pushed the Belarusian to three tough sets in Wuhan. She had lost five straight to Swiatek, then straight-setted her on the Parisian clay at the Olympics. Last fall, Qinwen salvaged just three games against Elena Rybakina in Beijing. This week she beat her. Zheng needed three sets to get past Jasmine Paolini last month; yesterday she allowed the Italian a measly 37 points.

The only player left in the Riyadh field that the Chinese woman hasn’t defeated is Coco Gauff. They’ve met just once, in Rome this season. Zheng won just 44% of points that day, landing an abysmal 41% of first serves. Should the pair meet to decide the season-ending championship, Gauff may still have enough of an edge to come out on top. But if we’ve learned anything from Qinwen’s four-month surge, it’s that she’s going to play a whole lot better this time.

* * *

Subscribe to the blog to receive each new post by email:

Aryna Sabalenka, Drop Shot Queen

*Aryna Sabalenka, watching another poor woman hopelessly run around*

In May this year, Aryna Sabalenka unleashed a new weapon: a drop shot she was willing to use far more than ever. After winning six of six drop-shot points in a Rome first-rounder against Katie Volynets, Sabalenka inflicted 28 droppers on Elina Svitolina. That match went to a third-set tiebreak, and her 15 outright drop-shot winners represented more than the margin of victory.

In her career up to that point, Sabalenka’s drop shots represented 1.1% of her (non-serve) strokes–about half the tour average of 2.2%. That rate nearly quadrupled, to 4.1%, for her eleven matches in Rome and Paris. On faster courts since, it has fallen, but not all the way back. Her drop-shot rate since June has been 1.9%. As we will see, the weapon has continued to give her more value even as she uses it less often.

The tactic makes perfect sense for a player with Sabalenka’s skills. She hits hard from the baseline, so opponents are usually positioned defensively, on the back foot. She’s capable in the forecourt (former doubles #1!), so not only does she have the touch to pull off the deception, she has the ability to deal with the rapid-fire net play that can ensue when someone runs a drop shot down.

The only question–had we thought to make the suggestion, say, a year ago–was whether the idea appealed to her. Not everyone is Carlos Alcaraz, ready to throw the tennis equivalent of a curveball into any point. Sabalenka was doing fine bashing groundstrokes into submission; why change? Now we know she’s comfortable with the tactic, even if 4% is probably reserved for the slowest courts.

How, then, does Aryna’s drop shot stack up against those of her peers, in terms of frequency, success rate, and value? I wrote two articles in March that outlined various ways of analyzing drop shot tactics. Those pieces looked at Alcaraz, Alexander Bublik, and the men’s game in general. The same approach can shed light on Sabalenka and the women’s tour, as well.

Getting the drop

All the data in this piece is based on the shot-by-shot logs from the Match Charting Project. I’ve limited the scope to the last decade. Nearly every tour-level Sabalenka match is charted, but for many other players, coverage is more limited. It’s also not necessarily random, so these numbers are approximate.

It’s also important to define “drop shot.” For the purposes of this piece, I’m looking only at the first drop shot in each point. “Re-drops” are a skill of their own, and probably a very different one. They are also tough to study because they are so much rarer than the already-uncommon standard drop shot. So we skip them for now.

Let’s start with the most prolific WTA drop-shotters since 2015. Remember that tour average is 2.2%–one dropper per 45 shots or so. Here are the thirteen women who have equaled or exceeded clay-Aryna’s 4.1% for their entire (charted) careers:

Player                Drop%  
Yulia Putintseva       8.6%  
Ons Jabeur             8.2%  
Laura Siegemund        7.6%  
Anastasija Sevastova   6.6%  
Marketa Vondrousova    6.3%  
Petra Martic           5.6%  
Kristina Mladenovic    5.2%  
Su Wei Hsieh           4.5%  
Agnieszka Radwanska    4.2%  
Karolina Muchova       4.2%  
Kiki Bertens           4.1%  
Viktorija Golubic      4.1%

Everything checks out so far. Putintseva dropshots to drive you nuts, Jabeur hits them to show off, and Aga did it just because she could.

The other end of the list has its amusements as well. In over 50 charted matches, spanning over 7,000 points, Camila Giorgi hit five drop shots. Yes, five. Two of them went for winners, and she lost the other three.

More important than frequency is points won. Here are the 14 women whose career drop-shot win rates surpass Sabalenka’s recent clip of 55.6%:

Player                 Drop%  Point W%  
Dominika Cibulkova      2.5%     61.4%  
Qinwen Zheng            2.0%     60.7%  
Sara Sorribes Tormo     2.3%     60.4%  
Ashleigh Barty          1.7%     59.5%  
Barbora Krejcikova      1.8%     59.0%  
Marketa Vondrousova     6.3%     58.7%  
Emma Raducanu           1.6%     58.3%  
Liudmila Samsonova      1.3%     58.2%  
Bianca Andreescu        3.2%     58.1%  
Anett Kontaveit         1.1%     57.4%  
Sofia Kenin             4.1%     57.4%  
Aliaksandra Sasnovich   3.3%     56.6%  
Sorana Cirstea          1.9%     56.3%  
Kiki Bertens            4.1%     56.1%  
…                                       
Average                 2.2%     52.6%  
…                                       
Aryna 2017-Apr '24      1.1%     53.2%  
Aryna 2024 Rome/RG      4.1%     61.9%  
Aryna 2024 2nd half     1.9%     55.6%

There is virtually no correlation between frequency and success rate, so players like Vondrousova and Kenin (and slow-clay Sabalenka) really stand out.

Here’s the same dataset, with more players, in visual form:

Most women cluster in the 1-2% frequency range, regardless of their drop-shot skills. Vondrousova and Putintseva really stand out for their combination of frequent attempts and consistent success.

Chasing down value

As much as youngsters dream of someday showing up on a leaderboard on this blog, what really matters is winning points. You can do that by hitting tons of drop shots and winning those points at a decent rate (like Putintseva), or by choosing moments carefully and executing well (like Qinwen Zheng).

Assume for the time being that the typical drop shot is hit from a perfectly neutral position, one in which each player has a 50% chance of winning the point. Combine the two metrics we’ve seen so far–multiply frequency by the difference between winning percentage and 50%–and we have the value added by a player’s drop shots. I’ve multiplied the results by 1,000 so all the zeroes don’t make our eyes hurt.

Player                 Drop%  Point W%  Drop Pts/1000  
Marketa Vondrousova     6.3%     58.7%            5.4  
(Aryna 2024 Rome/RG)    4.1%     61.9%            4.9  
Yulia Putintseva        8.6%     55.1%            4.4  
Sofia Kenin             4.1%     57.4%            3.0  
Dominika Cibulkova      2.5%     61.4%            2.9  
Kiki Bertens            4.1%     56.1%            2.5  
Bianca Andreescu        3.2%     58.1%            2.5  
Sara Sorribes Tormo     2.3%     60.4%            2.4  
Petra Martic            5.6%     54.2%            2.3  
Aliaksandra Sasnovich   3.3%     56.6%            2.2  
Qinwen Zheng            2.0%     60.7%            2.1  
Su Wei Hsieh            4.5%     54.5%            2.0  
Karolina Muchova        4.2%     54.8%            2.0  
...                                                   
(Aryna 2024 2nd half)   1.9%     55.6%            1.1  
Average                 2.2%     52.6%            0.6  
(Aryna 2017-Apr '24)    1.1%     53.2%            0.4  
...                                                    
Elise Mertens           1.9%     46.1%           -0.7  
Sloane Stephens         1.1%     42.2%           -0.8  
Amanda Anisimova        2.0%     45.8%           -0.9  
Kristina Mladenovic     5.2%     47.1%           -1.5  
Laura Siegemund         7.6%     47.7%           -1.7  
Ons Jabeur              8.2%     47.3%           -2.2

Clay may be particularly drop-shot friendly, but still, how about clay-Aryna!

At the other end of the spectrum… is Jabeur actually bad at drop shots? We need more context before we could establish any such conclusion. Perhaps the Tunisian hits droppers at particularly desperate times. Still, it’s jarring to see the star’s name at the bottom of the list.

Did someone say context?

The most common situation for a Sabalenka drop shot is when she makes a first serve and the ball comes back to her backhand. Over her entire career, when she hits a dropper with her second shot, she wins 51.1% of points. If she doesn’t go for the drop, she wins 51.8%.

Without camera-tracking data, that (and the dozen-plus analogous categories) is as far as we can drill down. Maybe the returns to the backhand that she dropshots are different from the ones she doesn’t. Match Charting Project data can’t tell us that.

Adjusting for context remains valuable even with those limitations. We can classify each drop shot by whether the player who hit it was the server or returner, whether it was a first or second serve point, whether it was a forehand or backhand-side drop shot, and how far into the rally it occurred. When Aryna waits one more shot on a first-serve point, her drop is much deadlier. Instead of the 47% of points she wins on a third shot from her backhand side with something other than a drop shot, she wins 55%.

The list looks quite a bit different when we take these additional factors into consideration. I tallied each player’s results in each of those categories, so we can compare their drop shot winning percentages with how they fared in the same mix of situations. “DSWOE” is Drop Shot Wins Over Expectation, the ratio between the two numbers:

Player               Drop W%  Exp W%  DSWOE  
Dominika Cibulkova     63.5%   50.1%   1.27  
Petra Martic           54.2%   42.9%   1.26  
Sara Sorribes Tormo    60.4%   47.9%   1.26  
Martina Trevisan       59.5%   48.7%   1.22  
Marketa Vondrousova    58.7%   48.1%   1.22  
Danka Kovinic          56.0%   46.1%   1.21  
Sorana Cirstea         56.8%   46.8%   1.21  
Kaja Juvan             58.5%   48.4%   1.21  
Ashleigh Barty         59.1%   49.3%   1.20  
Kiki Bertens           56.2%   47.2%   1.19
...  
Average                51.3%   49.2%   1.04
...  
Ons Jabeur             47.3%   47.8%   0.99  
Agnieszka Radwanska    48.9%   49.9%   0.98  
Maria Sakkari          48.6%   49.9%   0.97  
Jelena Ostapenko       49.7%   52.9%   0.94  
Caroline Wozniacki     50.0%   53.3%   0.94  
Elise Mertens          46.1%   50.2%   0.92  
Serena Williams        45.5%   49.8%   0.91  
Amanda Anisimova       45.8%   50.4%   0.91  
Sloane Stephens        44.1%   48.8%   0.90  
Iga Swiatek            49.6%   56.2%   0.88

(The winning percentages here are very slightly different from the ones above because some of the data wasn’t detailed enough to be used for this calculation.)

The average rate of 1.04 seems plausible. Players generally know what they’re doing; they wouldn’t hit drop shots if they didn’t have reason to think it would improve their odds. Jabeur does indeed look better in context. She still finds herself in the bottom ten, but a DSWOE of 0.99 means that if she is costing herself anything with all the droppers, it isn’t much. It’s possible that even this more granular approach is missing some details that would explain why Ons makes the decisions she does.

I must also acknowledge the oddity of finding Swiatek at the bottom of the list–or any list. Her 49.6% drop shot win rate isn’t that bad: It’s what she does the rest of the time that is such an outlier. She isn’t known for her drop shot, and she doesn’t hit many. So as with Jabeur, it’s possible that these categories don’t capture how hopeless the situations are when she tries to drag her opponent up to the net.

This metric confirms our story about Sabalenka. Her drop shots were fine–if rare–before May, became devilishly effective on the clay, then settled back to a more modest level on faster surfaces:

Player       Drop W%  Exp W%  DSWOE  
2017-April     53.3%   51.2%   1.04  
May            61.9%   51.4%   1.20  
Second Half    55.6%   52.4%   1.06

Buried in the details of Aryna’s respectable 1.06 ratio since June is a particularly encouraging trend. Remember those plus-one backhands that she shouldn’t have been dropshotting? Since June, she basically stopped. Out of 108 total drop shots, those have represented only five.

Drop and roll

For someone who hits as hard as Sabalenka does, throwing in a drop shot can be about more than just winning a point. Once an opponent realizes that they might have to chase down a dropper, they are that much less focused on defending against deep groundstrokes.

That’s the idea, anyway. When I wrote about drop shots in the men’s game, I was surprised to discover that drop shots didn’t influence the outcome of subsequent points in the way I expected. The majority of drop shots are hit by servers, but after they hit one, servers are less likely to win points later in the same game. If there is any discernable pattern in the ATP data, it is that once a drop shot is played–whichever player makes the move–the returner has an edge for the rest of the game. This probably isn’t a causal relationship: Perhaps drop shots are more likely to come into play when the server is struggling to control the action.

The data for women’s tennis tells a different story. On the point after a drop shot–win or lose!–the drop-shotting player wins 51.1% of the time. Two points later, there’s still an advantage, and the edge stays in place for the remainder of the game:

Situation          Win%  
Next point        51.1%  
Two points later  50.7%  
Same game         50.7%  
All others        49.9%

That advantage is not the same for every player. The following list shows the point winning percentages for players who get the biggest post-drop-shot bang for the buck, along with those who–like servers in the men’s game–see their post-drop fortunes dip.

Player                Same game  All others   Diff  
Jasmine Paolini           56.5%       50.4%   6.2%  
Marta Kostyuk             55.9%       50.1%   5.8%  
Sloane Stephens           55.0%       49.9%   5.1%  
Beatriz Haddad Maia       53.0%       48.7%   4.3%  
Qinwen Zheng              54.5%       50.7%   3.8%  
Naomi Osaka               54.5%       50.8%   3.7%  
Anastasija Sevastova      53.3%       49.7%   3.7%  
Maria Sakkari             53.1%       49.7%   3.3%  
Angelique Kerber          53.8%       50.5%   3.3%  
Su Wei Hsieh              50.9%       47.9%   3.1%  
Karolina Pliskova         54.0%       51.0%   3.1%  
Danielle Collins          53.7%       50.7%   2.9%  
Marketa Vondrousova       52.8%       50.0%   2.8%  
Agnieszka Radwanska       54.0%       51.4%   2.5%  
Garbine Muguruza          53.4%       50.9%   2.5%  
Aryna Sabalenka           55.0%       52.5%   2.5%  
…                                                   
Average                   50.7%       49.9%   0.7%  
…                                                   
Ons Jabeur                50.2%       50.3%   0.0%  
…                                                   
Emma Raducanu             49.6%       51.1%  -1.5%  
Ashleigh Barty            51.5%       53.0%  -1.5%  
Eugenie Bouchard          48.9%       50.6%  -1.7%  
Svetlana Kuznetsova       47.8%       49.8%  -2.0%  
Karolina Muchova          48.6%       50.7%  -2.1%  
Monica Niculescu          46.9%       49.1%  -2.2%  
Barbora Krejcikova        47.4%       50.1%  -2.7%  
Jessica Pegula            47.6%       50.6%  -2.9%  
Lesia Tsurenko            44.5%       47.5%  -3.0%  
Caroline Garcia           44.9%       49.6%  -4.7%

Jasmine Paolini! It’s tough to pinpoint exactly what she does that has caused her improvement in 2024. Her post-drop-shot success rate is too niche a skill to account for much of it, but it’s fascinating to consider.

I added Jabeur to this list because she illustrates one of the factors that makes analyzing drop shots so complicated. As noted, the theory is that once a player hits a drop, her opponent has to start thinking about it. But against Jabeur, opponents have to think about it from the moment they step on court! One more drop shot from the wizard isn’t going to change that.

That’s just one reason why the relationships between frequency, success rate, and post-drop-shot success rate are unpredictable. Some players, like Stephens and Osaka, play droppers rarely. They don’t win much when they do. But the after-effect might make up for it. At the other end, Muchova has a great drop shot that she deploys often, and for whatever reason, her results on subsequent points suffer.

Back to Sabalenka one last time. I snuck her into the table above because, even before she hit lots of drop shots, she saw a post-drop boost. You will not be surprised to learn that those numbers have gotten better in the last six months:

Span            Same game  All others  Diff  
2017 - Apr '24      54.3%       52.3%  1.9%  
2024 Rome/RG        60.2%       53.7%  6.5%  
2024 2nd half       58.9%       54.2%  4.8%

Clay-Sabalenka got the best of both worlds. She won more points by playing the drop, and she won more points because of the tactic’s lingering effect. Perhaps because of her growing reputation as a drop shot queen, the effect has persisted since June, even when she doesn’t go to the well so often.

The Aryna Sabalenka path to drop shot success won’t help everybody. But no matter how we slice up the numbers, it sure has worked for her.

* * *

Subscribe to the blog to receive each new post by email:

Does Mpetshi Perricard’s Backhand Even Matter?

*Giovanni Mpetshi Perricard in Basel, playing a longer rally than usual*.
*Credit: Skyscraper2010*

The story of last week’s tournament in Basel was the blistering service performance of Giovanni Mpetshi Perricard. The six-foot, eight-inch Frenchman racked up 109 aces in five matches, including more than one-third of his service points in Sunday’s final against Ben Shelton.

Mpetshi Perricard is a big server straight out of central casting. He can nail the corners at 150 miles per hour; on Sunday he hit one second serve at 146. He puts plenty of mustard on his groundstrokes as well. He often plays a high-risk brand of baseline tennis, recognizing that with a serve like his, he only needs to break once or twice–or just pick off a couple of return points in the tiebreak.

The Frenchman’s rapid rise through the ranks also fits his style. For a big server, wins can come in batches, when conditions–or, simply, tiebreak luck–are on his side. After an unexpected breakthrough on clay in Lyon, Mpetshi Perricard upset Sebastian Korda (in four tiebreaks!) and reached the second week at Wimbledon. Basel played faster than any tour event this year, and he took advantage. In between, he suffered through a 1-7 stretch in which he lost five straight tiebreaks and saw his double-fault rate balloon into double digits.

Much of Mpetshi Perricard’s future success will depend on his ability to handle these ups and downs. So far, he has struggled a bit to avoid the bad patches that spell doom for one-dimensional players. In his limited tour-level action, he has won more service points (70.2%) than anyone except Jannik Sinner. Yet five men hold more reliably than the Frenchman does, even after an unbroken week in Basel. The successes of Milos Raonic and John Isner–and even Shelton last year–come from playing better than usual under pressure, something Mpetshi Perricard has yet to consistently demonstrate.

I do love talking about servebots serving service aces. But while everybody raves about the GMP serve, I keep thinking about the backhand.

On the one hand

Mpetshi Perricard is now the fourth-highest ranked man with a one-handed backhand. His shot is nothing like the graceful, big-backswing, Federer- and Gasquet-inspired strokes of Grigor Dimitrov and Lorenzo Musetti. He often does little more than set up the racket to block the ball back. Strong as he is, the resulting flat shot can be much more than a mere defensive maneuver.

A few generations ago, it was standard to see big servers with one-handers. Think Richard Krajicek or Greg Rusedski; you might even put Pete Sampras in that category. More recently, Ivo Karlovic sported a one-handed backhand, though he mostly hit slices. Christopher Eubanks fits a broadly similar mold. Now, though, one-handers are dying breed, with just nine representatives in the top 100 of the ATP rankings.

Unlike Musetti or Stefanos Tsitsipas, Mpetshi Perricard isn’t likely to inspire the next generation of one-handed stars. No one is going to call this guy a throwback. On a good serving day, the Frenchman’s highlight reel features barely any groundstrokes at all.

What, then, do the numbers say? Is the Mpetshi Perricard backhand any good? Would he be better off with a two-hander like Raonic’s, Isner’s, or Reilly Opelka’s? Or, to return to the question I started with: For someone who specializes in ending rallies before they begin, does his backhand even matter?

Safely hidden

When the Frenchman’s game plan is working, his backhand is tucked away, out of sight. No backhands are necessary when the serve doesn’t come back, and when he controls the point, he prefers the forehand. Setting aside service returns, few players avoid their backhands as scrupulously as Mpetshi Perricard does.

The average ATPer hits 44% of their groundstrokes from the backhand side. Here are the most backhand-shy men with at least 15 matches in the Match Charting Project database, along with some other big servers of note:

Player                      BH/GS  
Ivo Karlovic                30.1%  
Jack Draper                 32.5%  
Ryan Harrison               35.2%  
Thiago Monteiro             35.5%  
Giovanni Mpetshi Perricard  35.5%  
Jaume Munar                 36.1%  
Vasek Pospisil              36.4%  
Alejandro Tabilo            37.1%  
Alexei Popyrin              37.3%  
Guido Pella                 37.4%  
Ben Shelton                 37.6%  
Maxime Cressy               37.9%  
…                                  
Christopher Eubanks         38.9%  
Matteo Berrettini           41.1%  
Milos Raonic                42.9%  
-- Average                  44.0%  
John Isner                  44.3%  
Reilly Opelka               45.6%  
Greg Rusedski               46.2%  
Nick Kyrgios                46.8%  
Pete Sampras                47.7%  
Richard Krajicek            48.3%  
Goran Ivanisevic            51.1%  
Mark Philippoussis          52.1%

Backhands per groundstroke is not the easiest stat to parse, because it is the product of so many different factors. Nearly everyone would like to keep their number low, so it’s partly a function of footwork and anticipation. (And sheer willingness to hit forehands from outlandish positions.) But it is also influenced by opponents, who will work more or less hard to find the backhand. Mpetshi Perricard’s place on this list, then, could be telling us various things. He hits his forehand when he can, and his movement is good enough to make it happen. Opponents might not be trying as hard as they could to force a backhand.

Yet another factor is how comfortable the player is with their slice. GMP hits his quite a bit, meaning that he unleashes the flat one-hander that much more rarely. The typical tour player hits their flat or top-spin backhand on 35% of groundstrokes. The Frenchman comes in at 25%, not as often as his most extreme peers, but in line with other big servers:

Player                      not-slice-BH/GS  
Ivo Karlovic                           6.1%  
Daniel Evans                          11.6%  
Milos Raonic                          20.2%  
Maxime Cressy                         20.4%  
Matteo Berrettini                     21.3%  
Grigor Dimitrov                       22.7%  
Corentin Moutet                       23.3%  
Christopher Eubanks                   23.6%  
Giovanni Mpetshi Perricard            25.2%  
Alexei Popyrin                        26.3%  
...
Bernard Tomic                         27.9%  
John Isner                            28.0%  
Ben Shelton                           28.5%  
Reilly Opelka                         31.5%  
-- Average                            34.7%

All of this is to say: Mpetshi Perricard hardly leans on the flat backhand. His serve keeps point short, and his preferences are for other shots. In the 138 points of the Basel final, he hit only 28 flat backhands, six of them on service returns.

Backhand impact

When the Frenchman is forced to hit a backhand (or chooses to–anything’s possible, I guess), the results aren’t great. When he goes for the flat backhand, he wins 43% of points, compared to a tour average of 49%. He takes more risks than his peers, but not overwhelmingly so: 9% of his one-handers end in a winner or forced error, while 12% are unforced errors. (Tour norms are 8% and 9%, respectively.)

These outcomes aren’t as extreme as his preferences. Of about 200 players with as many non-slice backhands in the MCP database, Mpetshi Perricard’s 43% comes in 21st from the bottom. Compared to other big servers, that win rate is positively respectable:

Player                      W/FE%   UFE%  inPointsWon%  
John Isner                   6.9%  12.8%         35.8%  
Milos Raonic                 7.3%  12.5%         40.4%  
Matteo Berrettini            4.8%  10.4%         42.5%  
Andy Roddick                 5.5%   7.8%         42.6%  
Felix Auger-Aliassime        6.0%   9.9%         43.4%  
Giovanni Mpetshi Perricard   8.9%  12.6%         43.5%  
Ben Shelton                  6.2%  11.1%         43.8%  
Nick Kyrgios                 7.9%  10.7%         43.9%  
Kevin Anderson               7.6%  11.0%         44.1%  
Hubert Hurkacz               6.2%  10.0%         45.6%  
-- Average                   7.3%   9.0%         48.6%  
Jack Draper                  6.5%   5.7%         49.1%

Against this group, the Frenchman’s winner (and forced error) rate really stands out. Given the outcomes when he doesn’t go for it, it’s possible he should be even more aggressive than he already is. Master tactician Milos Raonic took a similar tack, piling up as many unforced errors as GMP does, but without quite as many winners.

The picture is less rosy when we look at slice backhands. As noted, Mpetshi Perricard hits a lot of them–close to one-third of his groundstrokes from that wing. When he does, he wins 33% of points, compared to 42% for his peers. Only a handful of players have posted such low slice-backhand win rates, and they are mostly the names you would expect:

Player                      W/FE%   UFE%  inPointsWon%  
John Isner                   1.5%  11.1%         27.3%  
Christopher Eubanks          1.6%  10.7%         30.2%  
Kevin Anderson               3.2%   6.5%         31.4%  
Nicolas Jarry                4.0%  13.2%         32.7%  
Ivo Karlovic                 3.5%  12.0%         32.8%  
Giovanni Mpetshi Perricard   3.1%   3.9%         33.1%  
Ben Shelton                  2.0%   7.1%         33.3%  
...
Nick Kyrgios                 4.2%   6.1%         35.6%  
Felix Auger-Aliassime        3.6%   8.2%         38.1%  
Hubert Hurkacz               2.7%   3.9%         38.1%  
Milos Raonic                 4.7%   9.4%         40.3%  
Matteo Berrettini            2.8%   9.0%         41.5%  
-- Average                   3.3%   5.4%         41.6%

The Frenchman doesn’t miss much. Why just keep the ball in play, though, if you’re likely to lose the point anyway? By hitting so many slices, Mpetshi Perricard makes his flat-backhand numbers look better, but he probably doesn’t pick up any points by making the trade. Prolonging the point is a good strategy if you’re Casper Ruud–or, really, about 80% of the guys on tour. But if you play like GMP, it’s better to go big.

This is one way in which the one-hander may cost him. The two-handed backhand is particularly valuable in its ability to block overpowering shots without retreating to a fully defensive mode. While players with one-handers try to achieve the same thing with a slice, the stats tell us that it’s a poor imitation. The Frenchman’s in particular isn’t doing him any favors.

So, does it even matter?

Mpetshi Perricard doesn’t hit that many backhands, and he isn’t that much worse than average when he does. But, the margins in tennis are small, and the margins for big servers are smaller still. In 26 tour-level matches this year through the Basel final, GMP won exactly 50% of his points. (Not 50.1%, not 49.9%–50% on the dot.) Five players in the top 20 win 50.8% or less. That’s how close the Frenchman is to an even bigger breakthrough.

My backhand potency (BHP) stat quantifies the impact that each player’s (non-slice) backhands have on their broader results. The stat measures how often a shot ends the point in either direction, as well as what happens on the shot after that. Based on the matches we’ve charted this year, GMP’s BHP per 100 backhands stands at -4.3, one of the lower numbers on tour for players with at least 10 charted matches from the last 52 weeks:

Player                      BHP/100  
Nicolas Jarry                  -6.9  
Felix Auger Aliassime          -4.6  
Tallon Griekspoor              -4.6  
Flavio Cobolli                 -4.3  
Giovanni Mpetshi Perricard     -4.3  
Alexei Popyrin                 -4.2  
Dominic Thiem                  -4.1  
Botic Van De Zandschulp        -3.5  
Matteo Berrettini              -3.1  
Ben Shelton                    -2.4  
Stefanos Tsitsipas             -2.4

What does this mean for the bottom line? -4.3 BHP is equivalent to about -3 points per 100 backhands. Since he doesn’t hit many backhands, that’s about -1.1 per 100 points.

My best estimate, then, is that if we magically replaced the Frenchman’s backhand with a neutral one–say, that of Arthur Fils–he’d pick up 1.1 more points per 100. Instead of winning 50% of points at tour level, he’d win 51.1%. That isn’t good enough to crack the top 10, but it would probably get him into the top 20.

Quantifying the impact of slices is tougher, because the more conservative shot is less likely to end the point immediately, or even on the next shot. If we figure that Mpetshi Perricard’s slice is roughly the same distance below average as his flat backhand, that’s another 0.5 or 0.6 points per 100 he could gain by acquiring a tour-average shot. Daniil Medvedev has hung in the top five in the ATP rankings while winning 51.9% of points. Stringing all of these assumptions together, we can start to see how a capably-backhanded GMP could reach that level.

The bad news for the Frenchman is that climbing the ranks is hard. Mpetshi Perricard is the worst returner in the top 50, and it isn’t even close. He breaks in about 10% of his return games; no one else is below 14%. Earlier this year, I wrote about the similar challenges facing Ben Shelton: Historically, a lot of players have arrived on tour with big serves, huge potential, and tons of hype. Few of them have been able to shore up their weak points enough to crack the top ten, let alone achieve greater feats.

The good news: There is so much room for improvement. Even without polishing the strokes themselves, it’s possible that a more aggressive set of tactics could win him a few more points on return. In yesterday’s loss to Karen Khachanov, the Frenchman won the first set despite picking off just two of 37 return points. One-dimensional servebot or not, he can learn to do better than that.

* * *

Subscribe to the blog to receive each new post by email:

With Tommy Paul, Get Ready To Backhand

On Sunday, Tommy Paul won the Stockholm final with one well-executed tactic. He hammered the Grigor Dimitrov backhand, shot after shot, point after point. Paul hit 71% of his backhands cross-court, far above the tour average of 50%. He also aimed his forehands at Dimitrov’s weaker side, going inside-out with 38% of his forehands, compared to the typical clip of 24%.

The results: 6-4 6-3 to the American, and a paltry seven rally winners for his opponent. Dimitrov was forced to hit backhands for 58% of his non-return groundstrokes, compared to his usual hard-court rate of 43%.

Paul doesn’t have any overwhelming weapons of his own, so he wins matches–42 of them already this year–by neutralizing opponents. In the case of Sunday’s final, that meant putting pressure on a backhand that is more flashy than effective. Dimitrov’s signature one-hander is not the worst on tour, but it is not much of an asset. His career backhand potency (BHP) is negative, meaning it costs him more points than it gains. Paul’s elite movement allowed him to exploit a weakness that the Bulgarian can usually hide.

Grigor isn’t the only man on tour with a preference for the forehand. Even players with top-tier backhands will often opt for a forehand because of the angles it opens up. Paul’s ability to pepper the backhand, then, is often on display. Facing Jannik Sinner at the US Open, the American hit 60% of his backhands cross-court–good enough to push the world number one to two tiebreaks. At Indian Wells against Casper Ruud, he hit 61% of his backhands cross-court. That proved successful enough to secure his first top-ten win of the season.

Few pros play like this. Or more accurately: Few men are able to play like this. The Match Charting Project has at least 20 hard-court righty-versus-righty matches for almost 100 different men. Here are the top 15, ranked by how often they hit backhands cross-court.

Player                 BH XC%  
Lleyton Hewitt          70.0%  
Andre Agassi            65.9%  
Marat Safin             62.8%  
Yevgeny Kafelnikov      62.8%  
Richard Gasquet         59.8%  
Daniil Medvedev         59.4%  
Jenson Brooksby         59.3%  
James Blake             59.0%  
Kei Nishikori           58.7%  
Pete Sampras            58.6%  
Tommy Paul              58.6%  
Borna Coric             58.1%  
David Ferrer            58.0%  
Juan Martin del Potro   58.0%  
David Nalbandian        57.9%

That’s pretty good company. The active players highest on the list–Medvedev and Gasquet–are known for camping out far behind the baseline, giving them extra time to choose their shot. Paul and Nishikori (and the category-busting Brooksby) act faster. They rely on anticipation, footwork, and racket control to direct the ball where their opponent doesn’t want it to go.

Here’s a similar list–again, out of 100 or so players–ranked by inside-out forehand frequency. Same goal, different shot:

Player                 FH IO%  
Milos Raonic            39.5%  
Jack Sock               38.4%  
John Isner              38.1%  
Jim Courier             37.9%  
Reilly Opelka           33.3%  
Robin Haase             33.1%  
Andrey Rublev           33.0%  
Holger Rune             32.5%  
Daniel Evans            32.3%  
David Ferrer            32.3%  
Marin Cilic             31.8%  
Felix Auger-Aliassime   31.7%  
Thanasi Kokkinakis      31.6%  
Fabio Fognini           31.3%  
Kevin Anderson          31.1%  
Jo-Wilfried Tsonga      30.6%  
James Blake             30.1%  
Roberto Bautista Agut   30.0%  
Matteo Berrettini       29.9%  
Tommy Paul              29.7%

Many of these men make the list because they prey on weak service returns, or because they play high-risk shots when running around their backhands. Despite standing outside those categories, Paul ranks high on this metric as well. There’s very little overlap between the two lists: Only James Blake ranks above Tommy on both.

In short: Everybody (usually) wants to hit to the backhand, but few men are able to do so as often as Tommy Paul.

When tactics fail

Stockholm trophy in tow, Paul took his winning streak to Vienna. He began his campaign yesterday against compatriot Brandon Nakashima. Nakashima has become a thorn in Paul’s side, with three previous tour-level wins on three different surfaces. Tommy’s only victory came at a Challenger in 2019, when Nakashima was and 18-year-old ranked 942nd in the world.

Nothing changed this week. Nakashima secured a 6-4, 6-4 victory and improved his record against the older man to 4-1. Paul unleashed the same tactical plan that he used to beat Dimitrov, and he discovered–not for the first time–that it isn’t so effective against a sturdier backhand.

Paul hit nearly as many backhands cross-court as he did in the Stockholm final. But unlike Dimitrov, Nakashima was able to go toe-to-toe from that corner. Dimitrov went to the slice nearly half the time–opening up, incidentally, many of the opportunities Paul seized to hit inside-out forehands. Nakashima hit the slice barely half as often. 12% of Dimitrov’s topspin backhands became unforced errors; only 5% of Nakashima’s did.

*Nakashima took the tournament’s (unfortunately phrased) advice.*

We can’t explain the entire result based on Paul’s tactical preference. He looked sluggish throughout, coughing up 31 unforced errors compared with just 20 in the Stockholm final. But causation can run multiple directions: Nakashima didn’t allow him to play the clean, logical game that earned him the trophy in Sweden. The veteran scuffled to find another solution.

Another of Tommy’s worst matchups has a similar profile. He is 0-5 against Alex de Minaur, whose backhand also rarely lets him down. Both times they met in 2023, Paul hit his backhand cross-court more than 62% of the time. In Acapulco, the American hit his forehand inside-out more than 40% of the time, the highest mark we have for him in the Match Charting Project database. De Minaur doesn’t blow him off the court, so Paul can hit the shots he wants. Those shots–regardless of the Aussie’s own traits–are aimed at the backhand corner.

But against a player like Nakashima or de Minaur, the tactic doesn’t work. Lots of inside-out forehands are a safe bet against a player like Dimitrov, but de Minaur’s defense is too good. In Acapulco, Paul won only half of those inside-out forehands, well below tour average. The American generally played the way he wanted to, forcing de Minaur to hit a whopping 66% of his rally groundstrokes from the backhand side in their Los Cabos meeting. But the Aussie didn’t mind. At least in those matches, Paul showed little sign of a plan B.

Another dilemma for Tommy arises when someone takes away his plan A. The only other player who has defeated him five times is Andrey Rublev, hardly a man you’d select to run a backhand clinic. We don’t yet have any charted matches from this head-to-head, but it’s easy to speculate what goes wrong for Paul. In order to hit a disproportionate number of shots to a particular location, you need to have some control over the proceedings. Rublev, with his devastating forehand and aggressive mindset, is one of the few players on tour who can outslug the American’s speed.

The American’s losses are a good illustration of just how hard it is to excel at the highest levels of professional tennis. He is perhaps as good as anyone in the game at taking and keeping control of rallies from the baseline. But even that world-class skill can be nullified by a howitzer forehand or a backhand like a brick wall. Paul has twice upset Carlos Alcaraz, but when handed a first-round opponent with a solid backhand, as he was yesterday in Vienna, he sometimes finds that his best isn’t good enough.

* * *

Subscribe to the blog to receive each new post by email:

Matteo Berrettini and the Pursuit of Expected Value

*Matteo Berrettini hitting a forehand that will probably end the point*

A few weeks ago, Agustin Lebron made a broad claim:

Most strategic improvements in sports have been in the direction of increasing variance and living with the (better EV) results:
Baseball: more extra base hits, no more bunting.
Football: more passing game, going for it on 4th.
Golf: driver ball speed increases.
Bball: 3 pointer
Tennis: bigger serves/groundstrokes.
Snooker: cannoning the pack to extend breaks.
Chess: sub-optimal but niche exploitive lines.

“EV” means expected value or, roughly speaking, probability of success. Thanks to baseball’s sabermetric revolution and its influence on other sports, we better understand how players and teams win. Competitors, knowingly or not, are chasing EV.

Lebron’s claim is a bit more specific, that players and coaches across sports are playing riskier games because the ultimate payoff is greater. In baseball, a sacrifice bunt makes it more likely that a team scores one run, but less likely that the team piles on multiple runs. Hoopsters land two-point shots at a better rate than three-pointers, but the additional point makes the tradeoff worthwhile. Ice hockey coaches pull the goalie sooner than they used to, taking the chance that an extra skater will result in a game-tying goal, even if the decision could result in an easy score for the opposition.

Many more examples and counter-examples appear in the discussion around Lebron’s tweet and in the comments at Marginal Revolution.

It’s less clear that tennis ought to be grouped with these other sports. It may be true that players have uniformly bigger serves, or that they hit forehands harder than their predecessors. But is their pursuit of expected value causing them to take more risks?

Serve trends

Since 1991, when the ATP started recording stats like aces and double faults, aces have indeed gone up. That first year, about 5% of points ended with an untouched serve. The tour reached 7% by 2000, then cleared 8% in 2014. The rate has held fairly steady since then, sitting at 7.7% in 2024.

One way to hit more aces is to push closer to the edge. Aim for the lines, smack it as hard as you can, and accept that you’ll miss more, too. That would fit nicely with the increasing-variance hypothesis. But that’s not what has happened. As aces have gone up, the percent of first serves made has also risen:

The increasing-variance hypothesis holds for 1991-2000: Aces went up at the cost of fewer first serves in the box. Since then, though, players have kept hitting more aces (if only slightly), while landing even more first serves.

This is almost definitely thanks to better racket and string technology. You can swing harder than ever, with more spin than ever, and keep control of the ball. But that isn’t the whole story. For any given level of technology, players could take more risks, cracking still more aces at the expense of fewer first serves in. For nearly a quarter-century, that is not the decision pro men have made.

Second serves and double faults tell the same story:

Second serves offer an opportunity to take even more risks. If you go big and miss, you lose the point. But men have generally opted to take their chances with a ball in play. Double faults have cratered since the mid-90s and are currently at an all-time low. Yet players are winning about as many second serve points as ever.

In the last decade, we’ve seen a few players–Nick Kyrgios and Alexander Bublik come to mind–who do sometimes take their chances with a big second serve. Across 129 charted matches, Kyrgios hits aces on 4% of his second serves. Tour average is below 1%. Even Nick, though, doesn’t think it’s worth a major change in his risk profile. His career double fault rate is 4.2%: above average, but hardly an outlier among tour regulars.

The Aussie recognizes that the second serve evolved for a reason. Hitting a big second serve–deploying, in other words, two first serves–is a negative-EV play. It may be worth trotting out for variety’s sake, but not more than that.

Which brings us, finally, to Matteo Berrettini. The six-foot, five-inch Italian is the apotheosis of the big-serve, big-forehand, “plus-one” game. He’s the sort of player Lebron might have been thinking of when he bucketed tennis with the other sports on the list.

For all his power from the line, Berrettini is as conservative as they come. His career ace rate of 12.3% is outstanding, yet there is no apparent cost. He makes almost 64% of his first serves. He wins more second serve points than average, too, despite a miniscule double-fault rate of 2.4%. His game has gotten even safer as he reaches his late 20s. This year, he is hitting slightly more aces (12.8%) and landing far more first serves (68.6%) and committing fewer double faults (2.0%).

If the Italian is any indication, tennis is moving toward bigger serves and forehands. Yet when it comes to the serve, variance is headed in the opposite direction.

Rally aggression

What about groundstrokes? Nearly everyone these days talks about plus-one tennis. The serve–when it doesn’t end the point outright–generates opportunities to put the ball away. When those opportunities appear, don’t screw around! The strategy looks different in the hands of Berrettini than it does with, say, Jelena Ostapenko, but more than ever, players think in terms of recognizing and converting opportunities to end points.

Once the serve has landed, some players have indeed adopted a higher-variance approach that is probably unprecedented. Ostapenko, the freest swinger of all, ends nearly two-thirds of points on her own racket. Inevitably, she misses a huge fraction of those. Her Rally Aggression score of 182 (on a scale designed to run from -100 to 100) leads active players, and it massively outstrips anyone who started their career before about 2005.

Here, alas, we are hamstrung by data limitations. I discussed the men’s tour above because women’s ace and double-fault data only goes back to 2010 or so. The situation is even worse with groundstrokes. While the Match Charting Project now spans over 14,000 matches, relatively few of those predate 2010. Those “early” matches are heavily skewed toward a handful of top players.

We can still draw some comparisons. Lindsay Davenport and Maria Sharapova, often-erratic free swingers a generation or two before Ostapenko, grade out with Rally Aggression scores in the mid-40s. That’s below Iga Swiatek. Let that sink in for a moment. Today’s rock-solid, heavy-topspinning queen of clay plays as aggressively as two earlier-era emblems of high-risk slugging.

Again, we see the effect of better tech. When Ostapenko swings away, there is perhaps a 60% chance it lands in. If it does, it probably isn’t coming back. When Davenport (or to a greater extent, her own predecessors) took a big cut with a 60/40 chance of falling between the lines, it wasn’t quite as hard, and it didn’t have as much spin. It was that much less likely to end the point immediately, or in her favor at all. The chance of an error was always high; modern rackets and strings have upped the odds that the risk is worth taking.

Berrettini, though, once again illustrates that the risk isn’t necessary. The Italian’s Rally Aggression score is 24: above average but not by much. In part the number is low because he struggles to create opportunities on return (or when his serve fails to create chances), but in part he rates where he does because he doesn’t often miss. Roger Federer, for broadly similar reasons, is in the same range.

Modern tech allows players to hit as many winners as ever with less risk. Jannik Sinner, with his career Rally Aggression score of -24 and Carlos Alcaraz, at +8, point toward a lower-variance future, at least in the men’s game.

Ebbs and flows, serves and volleys

The biggest gap in the increasing-variance hypothesis is that it doesn’t explain the death of the serve-and-volley.

Few tactics in any sport are higher variance than old-school, rush-the-net-on-every-point serve-and-volleying. Think of Boris Becker at Wimbledon. He hit a bomb, and if it came back, he was often sprawled across the court simply trying to get a racket on the ball. Today’s net forays aren’t always so kinetic, but they remain high-risk. For every easy volley, there’s an untouchable passing-shot winner.

What’s more, the most dedicated form of serve-and-volleying, Jack Kramer’s “Big Game,” was explicitly an EV play, the brainchild of an actual engineer decades before anyone thought to put “sports” and “analytics” in the same sentence. Kramer and club-mate Cliff Roche worked out the angles and the probabilities, and the on-court results were so overwhelmingly positive that other Americans quickly followed suit. Thanks to a Davis Cup drubbing in 1946, Kramer’s game also changed the course of Australian tennis, inspiring Frank Sedgman and indirectly defining the style of innumerable hopefuls, including Rod Laver.

Serve-and-volleying, in the right hands, was the smart play for reasons that no longer persist. Returners couldn’t do much with a good serve. Court conditions made baseline tennis chancy: Much more tennis was played on grass, and almost none of that grass resembled the impeccable grounds at Wimbledon. Rushing the net was the only way to avoid losing on a bad bounce.

There’s a direct line running from Kramer, through Laver and Pete Sampras, to early-career Federer. Roger gave up serve-and-volleying only when Lleyton Hewitt showed how a sturdy, precise defense–made possible, again, by improved tech–could turn even a strong serve-and-volley attack into a negative-EV proposition.

The overarching theme here is that tennis pros will chase expected value, just as they have for a century. If they don’t, other players will come along with a better approach and displace them. The tactics that work in a given era are heavily driven by tech, and they may or may not move in the direction of higher variance.

The women’s game shows us the potential of high-risk tennis. So many top players go for broke that someone like Swiatek–an aggressive player by historical standards–looks conservative by comparison. Ostapenko-style slugging looks nothing like serve-and-volleying, but the philosophy is similar: Put the ball away before your opponent has the chance.

The men’s game, though, is becoming ever more precise. Sinner and Alcaraz don’t have low Rally Aggression scores because they play so passively. They just don’t miss very often. Berrettini is more aggressive, but only just. Few men hit serves harder or pepper the corners so persistently. Fewer still are so relentless in how they capitalize on a short ball. Yet he does that seemingly without cost. The Italian has plenty of limitations–injuries and a limited backhand, for starters–but they aren’t tactical. He and his colleagues have concluded that higher risks aren’t worth it, and they are probably right.

* * *

Subscribe to the blog to receive each new post by email: