Are Two First Serves Ever Better Than One?

It’s one of those ideas that never really goes away. Some players have such strong first serves that we often wonder what would happen if they hit only first serves. That is, if a player went all-out on every serve, would his results be any better?

Last year, Carl Bialik answered that question: It’s a reasonably straightforward “no.”

Bialik showed that among ATP tour regulars in 2014, only Ivo Karlovic would benefit from what I’ll call the “double-first” strategy, and his gains would be minimal. When I ran the numbers for 2015–assuming for all players that their rates of making first serves and winning first-serve points would stay the same–I found that Karlovic only breaks even. Going back to 2010, 2014 Ivo was the only player-season with at least 40 matches for whom two first serves would be better than one.

Still, it’s not an open-and-shut case. What struck me is that the disadvantage of a double-first strategy would be so minimal. For Karlovic (and others, mainly big servers, such as Jerzy Janowicz, Milos Raonic,and John Isner), hitting two first serves would only slightly decrease their overall rate of service points won. For Rafael Nadal and Andy Murray, opting for double-first would reduce their rate of service points won by just under two percentage points.

Here’s a visual look at 2015 tour regulars (minimum 30 matches), showing the hypothetical disadvantage of two first serves. The diagonal line is the breakeven level; Ivo, Janowicz, and Isner are the three points nearly on the line.


Since some players are so close to breaking even, I started to wonder if some matchups make the double-first strategy a winning proposition. For example, Novak Djokovic is so dominant against second serves that, perhaps, opponents would be better off letting him see only first serves.

However, it remains a good idea–at least in general–to take the traditional approach against Djokovic. Hypothetically, two first serves would result in Novak raising his rate of return points won by 1.2 percentage points. Gilles Simon and Andy Murray are in similar territory, right around 1 percentage point.

Here’s the same plot, showing the disadvantage of double-first against tour-regular returners this season:


There just aren’t any returners who would cause the strategy to come as close to breaking even as some big servers do.

The match-level tactic

What happens if a nearly-breakeven server, like Karlovic, faces a not-far-from-breakeven returner, like Djokovic? If opting for double-first is almost a good idea for Ivo against the average returner, what happens when he faces someone particularly skilled at attacking second serves?

Sure enough, there are lots of matches in which two first serves would have been better than one. I found about 1300 matches between tour regulars (players with 30+ matches) this season, and for each one, I calculated each player’s actual service points won along with their estimated points won had they hit two first serves. About one-quarter of the time, double-first would have been an improvement.

This finding holds up in longer matches, too, avoiding some of the danger of tiny samples in short matches. In one-quarter of longer-than-average matches, a player would have still benefited from the double-first strategy. Here’s a look at how those matches are distributed:


Finally, some action on the left side of the line! One of those outliers in the far upper right of the graph is, in fact, Ivo’s upset of Djokovic in Doha this year. Karlovic won 85% of first-serve points but only 50% of second-serve points. Had he hit only first serves, he would’ve won about 79% of his service points instead of the 75% that he recorded that day.

Another standout example is Karlovic’s match against Simon in Cincinnati. Ivo won 81% of first-serve points and only 39% of second-serve points. He won the match anyway, but if he had pursued a double-first strategy, Simon could’ve caught an earlier flight home.

Predicting double-first opportunities

Armed with all this data, we would still have a very difficult time identifying opportunities for players to take advantage of the strategy.

For each player in every match, I multiplied his “double-first disadvantage” (the number of percentage points of serve points won he would lose by hitting two first serves) with the returner’s double-first disadvantage. Ranking all matches by the resulting product puts combinations like Karlovic-Djokovic and Murray-Isner together at one extreme. If we are to find instances where we could retroactively predict an advantage from hitting two first serves, they would be here.

When we divide all these matches into quintiles, there is a strong relationship between the double-first results we would predict using season-aggregate numbers and the double-first results we see in individual matches. However, even if the most double-first-friendly quintile–the one filled with Ivo serving and Novak returning–there’s still, on average, a one-percentage-point advantage to the traditional serving tactic.

It is only at the most extreme that we could even consider recommending two first serves. When we take the 2% of matches with the smallest products–that is, the ones we would most expect to benefit from double first–26 of those 50 matches are one in which the server would’ve done better to hit two first serves.

In other words, there’s a ton of variance at the individual match level, and since the margins are so slim, there are almost no situations where it would be sensible for a player to hit two first serves.

A brief coda in the real world

All of this analysis is based on some simplifying assumptions, namely that players would make their first serves at the same rate if they were hitting two instead of one, and that players would win the same number of points behind their first serves even if they were hitting them twice as often.

We can only speculate how much those assumptions mask. I suspect that if a player hit only first serves, he would be more likely to see streaks of both success and failure; without second serves to mix things up, it would be easier to find oneself repeating mechanics, whether perfect or flawed.

The second assumption is probably the more important one. If a server hit only first serves, his ability to mix things up and disguise serving patterns would be hampered. I have no idea how much that would affect the outcome of service points–but it would probably act to the advantage of the returner.

All that said, even if we can’t recommend that players hit two first serves in any but the extreme matchups, it is worth emphasizing that the margins we’re discussing are small. And since they are small, the risk of hitting big second serves isn’t that great. There may be room for players to profitably experiment with more aggressive second serving, especially when a returner starts crushing second serves.

Ceding the advantage on second-serve points to a player like Djokovic must be disheartening. If the risk of a few more double faults is tolerable, we may have stumbled on a way for servers to occasionally stop the bleeding.

Premier or International? Balancing Rewards and Draw Quality

This week, WTA players had a choice of tournaments: a Premier event in Stanford or an International in Washington. Stanford offers far more ranking points–470 to Washington’s 280 for the winner–and an even bigger difference in prize money–$120,000 to $43,000.

For the very best players, it’s an easy choice to head for the event with the biggest rewards. But further down the rankings, it’s not so clear cut. If enough top contenders gather at one tournament, there may be easier points (and dollars) for the taking elsewhere.

The pairing of Stanford and Washington provides a neat natural experiment that allows us to analyze players’ scheduling decisions. Both tournaments are in the same country and played on the same surface. The only major difference is the package of available rewards.

(Of course, for any particular player, there may be other strong reasons to choose one event or the other, such as local ties, previous success at the event, sponsorship commitments, or appearance fees. Also, some players might opt for Washington because of its closer proximity–and lack of time zone changes–to upcoming events in Montreal, Cincinnati, and New York. For the purpose of this analysis, though, we’ll have to ignore personal considerations.)

Lucie’s choice

Let’s start with an example: Lucie Safarova. The 17th-ranked Czech is the top seed in Washington. Before the draw was released, a simple ranking-based projection would’ve given her a 14% chance of winning the title, making her the favorite. Had she entered Stanford, she would’ve been the 8th seed, and a similar forecast would’ve given her a 3% chance of winning the title.

Advantage Washington? If Lucie wants prestige, a trophy, and more time on court, yes. But if she prefers ranking points and cash, she still should have gone to California.

That 14% chance of winning the Citi Open title, combined with her pre-tournament odds of reaching each preceding round, gives Safarova a weighted forecast of 87 ranking points and $11,800 in prize money. Had she opted for Stanford, her weighted expectation would be 95 ranking points and $21,170.

Safarova’s comparison is indicative of what we find with many more players in action this week. Even with a higher chance of advancing to the final rounds in Washington, the ranking point balance tilts in Stanford’s favor, and the prize money difference is even more extreme.

California cash

The contrast between the two events is much starker in terms of dollars than in points. As we’ve seen, the champion in Stanford receives almost three times as much as her fellow trophy-winner in Washington, but not even twice as many ranking points.

Because the prize-money pot is so much bigger in Stanford, every direct-entry player in the draws of both tournaments would have expected a bigger check from Stanford. The differences run from the extreme–Agnieszka Radwanska could have expected only 38% as much prize money in Washington than in Stanford–to the less outrageous–Ekaterina Makarova, the Citi Open #2 seed, can expect 67% as much cash in DC as she would have expected in Stanford.

Still, every single player with the option to enter either event could have expected a bigger paycheck had they chosen Stanford.

Ranking point decisions

When it comes to WTA ranking points, Stanford holds much less of an edge. Of the 48 direct-entry players in the two tournaments, 11 of them can expect more ranking points in Washington than in Stanford, including Makarova, whose expected points haul is 15% greater in DC than it would’ve been at Bank of the West.  Most of the players who would’ve done better in Washington would be seeded in DC but not in Stanford, giving them the likelihood of a much easier early-round draw at the east-coast event.

Still, for the majority of players, the bigger rewards in Stanford outweigh the difficulty of the competition. 37 of the 48 direct entries would be expected to earn more points in Stanford, and for 15 of them, their expected points in Washington would be less than 80% as much as the comparable number in California. Nine of those 15 are playing Washington. In fairness, a few of those players were ranked below the cut for Stanford, so they didn’t have a choice.

On average, players in action this week could expect 15% more ranking points in Stanford than in Washington, along with double the prize money.

Smart choices

Not every player is going to maximize her chances of winning money and racking up points every week. But it does seem extreme that, given the choices that players made this week, the balance between risks (crashing out early to a great player) and rewards (points and cash) seems so out of whack.

It may be that secondary concerns, like proximity to other events, hold more importance that I am giving them credit for. It could be that, in the run-up to higher-stakes events next month, some players are interested in playing more matches. The Citi Open does offer the likelihood of that.  Also, some players commit to one event or the other before knowing much about the relative field strength–there is the possibility that players underestimated the quality of this year’s Washington draw, which has not always been so strong.

Still, it is striking to find little evidence that players made optimal choices. On average, the players who chose Stanford could expect 16% more ranking points than if they had played Washington. The players who opted for DC could have expected 14% more ranking points in Stanford–basically the same as their colleagues on the other coast.

With this much at stake, many players could’ve improved their lot simply by thinking through their options a little better. In general, if you’re likely to be seeded at one tournament and not the other, go where the seed is. If you will be seeded at both or unseeded at both, go where the higher stakes are.

For more detail on methodology, keep reading.

Continue reading Premier or International? Balancing Rewards and Draw Quality

Roger Federer’s Break Point Opportunities

Remember Roger Federer‘s dreadful performance on break points against Tommy Robredo at last year’s US Open?  Of course you do. He had 16 chances to break, converted only two of them, and lost the match in straight sets.  Then we all cried.

Yesterday, Federer won in straight sets against James Duckworth, but his break point performance wasn’t much better.  Four breaks of serve was all he needed to cruise to victory, but the Australian saved 13 other break chances.  In his disappointing loss to Lleyton Hewitt in Brisbane, Fed only converted 1 of 10 break chances.

Is this the end? Is a lack of break point conversions the monster that will finally slay the old man?

Not so fast.

To identify how bad (or, possibly, good) Federer has been on break points, we must compare that performance to his record on other return points.  Roger isn’t same kind of master returner as Novak Djokovic or Rafael Nadal, so it would be unrealistic to expect him to convert as many break points as they do.  To control for general returning ability, we must compare break point conversion rate to winning percentage on all other return points.

Sure enough, 2013 wasn’t a good year for Fed.  His break point conversion rate was 8% lower than his winning percentage on other return points.  When I ran these numbers after the Robredo match, that ranked 40th out of the ATP top 50.

Most of us, thinking back to Fed’s glory days, surely imagine that this is new.  And it’s true: 2013 was a bad year. But watch out for runaway narratives–there’s more randomness here than trend.  The graph below shows how Fed has performed each year on break point conversions.  A number above 1 is good: He’s winning more break point chances than other return points, as in 2009, when he exceeded expectations by 4.4%. Below 1 is bad: Last year was 7.8% below expectations.


If you see a pattern here, I’m impressed.  2013 was bad, but not as bad as 2003, when 21-year-old Fed performed more than 10% worse on break point chances than on other return points.  He also went 78-17, winning seven tournaments, including Wimbledon and the Masters Cup, raising his ranking from #6 to #2.

Last year’s break point record was also comparable to 2007, when he converted 5.9% fewer break points than expected … and won three Grand Slams.

As with so many popular tennis stats, this one just doesn’t have that much of a relationship with winning.  Breaks matter, but missed break chances don’t. In Federer’s case, even breaks don’t always matter that much–he’s one of history’s best in tiebreaks.

The bigger picture with break point conversions

Over his career, Federer has been just a tick below average on break point, winning about 1.5% more other return points than break points.  The year-to-year fluctuations don’t appear to be terribly meaningful.

That isn’t to say that no player has strong break point tendencies.  Nadal has consistently excelled in these clutch situations, winning more break points than expected for each of the last five seasons.  He is even better when facing break point, typically winning about 7% more service points in that situation than in others.  (Some of that is due to the advantage of a lefty serving in the ad court.)

Novak Djokovic has also been a little better on break points than on return points as a whole. But last year–a season he finished within a whisker of #1–his performance in those situations was almost as poor as Federer’s.

Andy Murray is consistent when handed break point chances–consistently bad.  Since 2006, he has only exceeded expectations once. In 2012–a pretty good year from him by most standards–he won 7.3% fewer break point chances than other return points.

David Ferrer? A tick below expectations. 7.7% below other return points in 2013. Juan Martin del Potro? Consistently above expectations, including an impressive +6.8% in 2011.  Stanislas Wawrinka? -7.3% in 2011, +7.8% in 2012, then in his breakthrough 2013 campaign, -3.0%.

Constant exposure to break point stats has tricked us into thinking they are particularly meaningful. There are plenty of reasons why Federer is winning fewer matches than he used to–for one thing, he’s almost as old as I am–but break point performance just isn’t that important.

Richard Gasquet and Fifty-Win Seasons

When Richard Gasquet beat Kei Nishikori to reach the quarterfinals in Paris this week, he won his 50th match of the year, putting him in that rarefied company for the first time in his career.  Six years after his near-miss 49-win 2007 campaign, he finally becomes the 123rd player in the professional era to post such a total.

Given the shorter ATP schedule favored by top players these days, a 50-win season isn’t as easy to come by as it once was.  Between 1972 and 1982, there were six 100-win seasons, while no one has even played 100 matches in a season since Yevgeny Kafelnikov did so in 2000.

Gasquet is one of only six players to reach the 50-win mark this year–the others are Novak Djokovic, Rafael Nadal, David Ferrer, Juan Martin del Potro, and Tomas Berdych, while Stanislas Wawrinka could get there with one win in London.  Six is the lowest total since 2004, when only five players reached the 50-win plateau.

Going back to the 1970s, however, the ATP sported 50-match winners in double digits every season from 1971 to 1980, peaking with 16 in 1974 and 1975.   In recent years, 10 players have reached the mark only once since 1994.

With only 123 players in ATP history, the list of 50-match winners is a select one.  Jimmy Connors tallied 50 wins 14 times, Ivan Lendl 12 times, Roger Federer 11 times, Guillermo Vilas and Stefan Edberg 10 times each.  Nadal is up to eight, while Djokovic is right behind him at seven.

The next highest active player on the list, David Ferrer, is an interesting case, especially in the context of Gasquet’s maiden 50-win season.  Aside from the stars of the early 70s, most of the biggest names in tennis posted their first 50-win campaign in their early 20s, if not sooner.  Connors and Lendl did so at 20, while Federer did so at 21.  Ferrer, on the other hand, is finishing up his fifth 50-win season, despite having none until age 25.  The only modern-era player who compares is Thomas Muster, who had four 50-win seasons, the first of which when he was 26.

Gasquet is 27, and while he’s not the only man to start tallying 50-win seasons so late, he enters an awfully small group.  Again setting aside players of the early 70s, only 12 men posted their first 50-win season at age 27 or later.  Among them are some familiar recent names, including Nicolas Almagro last year, Janko Tipsarevic the last two years, and Jurgen Melzer in 2010.  The Austrian is the record-holding oldest of the bunch, having enjoyed his 50-win campaign at age 29.

While many of us hope that this is a breakout season for Richard, these comparisons aren’t encouraging.  Of the 11 other players in this group, only two–Tipsarevic and James Blake–posted another 50-win season.  Melzer, for instance, hasn’t topped 30 since his big year.  If we are entering the Gasquet era, it will likely be a short one.

The same reasoning, alas, applies to Wawrinka, who may yet reach the 50-win plateau.  About 15 months older than the Frenchman, he would be second only to Melzer as the oldest player to register his first 50-win season.  The Ferrer comparison offers a glimmer of hope, as it is increasingly common for players to enjoy late peaks.  But if we’re seeing Gasquet or Wawrinka win 50 matches in, say, 2015 or 2016, it would be far more noteworthy than their excellent current seasons.

Djokovic d. Wawrinka: Recap and Detailed Stats

Stanislas Wawrinka came into his first Grand Slam semifinal match today as an extreme underdog.  (I made the case for that this morning.)  For the second consecutive Slam encounter with Novak Djokovic, he nearly scored the upset.

As was the case with Andy Murray in Wawrinka’s quarterfinal match, Djokovic didn’t look like a top-three player, especially for the first hour or so.  He dropped the first set 6-2, making way too many errors (18, against only six winners), and failing to take advantage of Stan’s complete inability to put a first serve in the box.

A few games later, the match turned even further in the direction of the Swiss.  After a marathon, 18-point game at 1-2, Wawrinka saved three break points then won a couple of long rallies in the following game to score the first break of the second set.  However, Wawrinka’s first-serve percentage caught up to him while Djokovic started to play slightly better tennis.  Novak broke to even things up at 4-4, and both players continued to hold serve into a tiebreak.

In retrospect, that second-set tiebreak was the turning point.  And if we had to isolate one point, it would be the one on Wawrinka’s racquet at 2-3, when he double faulted.  He never got the mini-break back.

The Swiss only double-faulted six times in the match–not bad for a 331-point contest–but the rough patch in that second-set tiebreak was the first of three very important points he threw away with his serve.  He double-faulted on break point in the first game of the fourth set, giving Djokovic a break he would never recover.  And at game point, 40-30, at 1-1 in the fifth, he double-faulted to give Djokovic an opportunity at deuce.

That third game of the fifth set will go down in the record books.  It lasted 30 points, progressing through twelve deuces.  Djokovic had five break points, and Stan saved them all.

At the time, it felt like a turning point.  After all, what else could a 12-deuce game be?  Looking back, it was Wawrinka’s last hurrah.

It is remarkable that Wawrinka, playing against the best returner in the game, earned the result he did.  He barely made half of his first serves, never topping 55% in a single set.  It’s remarkable, either a testament to Stan’s ground game or an indication of Djokovic’s poor play today, that he won half of those second-serve points.

And by the fifth set, his ability to play on was increasingly in question.  At 4-1 in the fourth set, Wawrinka left the court for a medical time out, getting a tape job on his upper thighs.  He clearly wasn’t moving as well after that, though the results barely show it.  Somehow he continued to fight Djokovic for every point.  He took a few more chances–including some reckless ones–but continued to slug it out in plenty of long rallies.

But in the service game following the marathon hold, Wawrinka’s magic didn’t hold.  He saved two more break points, but on the eighth chance of the set, Novak finally broke.  There wouldn’t be another chance.  From 3-2, Wawrinka continued to hold serve, but no game would reach deuce.

It was a great effort from the Swiss.  Like his straight-set win over Murray, it is, one hopes, a sign of things to come.  Save Nadal, Wawrinka has played as well as anyone this fortnight.  He’s no young rising star, but in the few years remaining in his professional career, he deserves, at the very least, another shot at a Grand Slam semifinal.

Here are the complete point-by-point stats from the match.

Djokovic the Favorite, Murray the Vulnerable, Smyczek the Last Hope?

Last night, Novak Djokovic cemented his status as the US Open favorite, all without doing a thing.

The 32-man draw has 19 seeds left, but only two others remain in Novak’s quarter, and those two–Tommy Haas and Mikhail Youzhny–play each other in the 3rd round.  Djokovic will face the shocking Joao Sousa in his third-rounder, followed by the winner of Tim SmyczekMarcel Granollers in the fourth.

Novak’s quarterfinal threat was supposed to be Juan Martin del Potro, and that’s where the Serbian has really gained.  Lleyton Hewitt upset Delpo in a slipshod five-setter last night, making Djokovic’s most likely QF opponent Tommy Haas. While Haas has a recent win against the world #1, you have to figure he remains the preferred opponent.

These shifts in the draw mean that my forecast now gives Djokovic almost exactly double the chances of winning of his nearest competitor, Rafael Nadal.  Nadal, of course, has a much trickier path to the semifinals, likely having to go through both John Isner and Roger Federer.  Andy Murray has a more fortunate draw than that, but he’ll probably need to beat Tomas Berdych to earn a matchup with Djokovic.

Djokovic didn’t look dominant in his second-round win, but it was Murray who lost a set yesterday, to journeyman Argentine Leonardo Mayer, a 26-year-old who has yet to crack the top 50.  The defending champion recovered just fine, but is second-round weakness a sign of bad things to come?

The short answer is no.  Since 1991, seven US Open champions have been pushed to four or five sets in their second round match en route to the title, though none have suffered that fate since 2004, when eventual champ Federer dropped a set to Marcos Baghdatis.  Another three titlists lost at least one set in the first round.

However, few of those early-round challengers have been as anonymous as Mayer.  Besides Baghdatis, the most recent second-round threats have been Ivan Ljubicic and James Blake.  The last time an Open champion dropped a second-round set to such an anonymous figure was in 2000, when Marat Safin needed five sets to get past Gianluca Pozzi.

Also worth noting is that in Murray’s trio of notable victories–last year’s Olympics and US Open, plus this year’s Wimbledon–he has never dropped a set so early.  In fact, in London this summer, he won his first four matches in straights before battling through a five-setter against Fernando Verdasco.

Whatever else you might say about Verdasco, he’s a much more dangerous opponent than Leonardo Mayer.

American grinder Tim Smyczek scored the biggest win of his career yesterday with a five-set victory over Alex Bogomolov.  Smyczek has taken advantage of an easy draw (Bogie defeated Benoit Paire in the first round) to reach his first Grand Slam round of 32 in his fifth main draw appearance.

He has a rare opportunity to go even further, facing 43rd-ranked Marcel Granollers, also the beneficiary of a friendly draw thanks to Fabio Fognini‘s first-round loss.  Granollers has played 18 slams on hard and grass courts, never reaching the round of 16.

It’s a strange world when Smyczek is one of only three Americans–along with John Isner and Jack Sock–still alive.  Stranger still is the very real possibility that Tim will be the only man standing two days from now.  Sock faces Janko Tipsarevic, a winnable match but not one he’ll be favored in.  Isner is ranked higher than his next opponent, Philipp Kohlschreiber, but the German eliminated him in last year’s Open.

Smyczek, on the other hand, has nothing to lose.  Well, except for his pride, when he reaches the fourth round and suffers a triple-bagel at the hands of Novak Djokovic.

If you’re already worrying about not having enough matches to watch during week two, look no further than Colette Lewis’s thorough US Open Juniors preview, which lays out the contenders in both the boys’ and girls’ draw.

Duval’s Triumph, Isner’s Breaks, Flushing’s Favorites

17-year-old Victoria Duval, she of six career tour-level matches, upset 2011 champion and 11th seed Samantha Stosur last night.  Leave it at that, and it sounds pretty impressive.

But it doesn’t quite convey how impressive the youngster’s path to the second round has been.  Duval is ranked just inside the top 300–not high enough to get into the qualifying tournament on that basis.  Armed with a wild card, she beat three players, each with considerably more experience than she has.

Reaching a Grand Slam main draw as a qualifying wild card is notable in and of itself.  The only one of this year’s nine qualie WCs to reach the main draw, she’s only the 16th woman to do so at the US Open since 1998 and only the 31st woman to do so at any Slam in that time frame.

As we now know, she didn’t stop there, and that sets her further apart.  Of the 30 women who previous accomplished the feat, only 11 went on to win a match in the main draw.  (Only one of those, Great Britain’s Karen Cross, at Wimbledon in 1997, won two main draw matches.)  And only one of those ladies–Yulia Fedossova, who qualified for the US Open in 2006–beat a seed.  Her victim was the much less imposing 25th seed, Anabel Medina Garrigues.

Every slam has its share of upsets, but this one goes far beyond that.  By beating a former champion and highly-seeded player, Duval did something no woman had done before.

Yesterday was a good day for American men, who went 5-2.  The only victims were Steve Johnson, who struggled with injuries, and junior champion Collin Altamirano, who no one could’ve expected would give Philipp Kohlschreiber much of a fight.

More notable than the simple fact of winning was the manner in which two US men did so.  In the battle of oppositesJohn Isner defeated Filippo Volandri, 6-0 6-2 6-3, and Donald Young knocked out Martin Klizan, 6-1 6-0 6-1.

Isner set all kinds of personal records in the process.  Not known for his return game–to put it mildly–Isner had never won a bagel set on hard courts.  In fact, until beating Adrian Mannarino in Newport last month, he had never won a set of professional tennis 6-0.

Next, also because of that not-so-pesky return game, Isner tends to lose quite a few games, even when he’s winning.  In best-of-five matches, he had never before won a match without dropping at least nine games.  (That was at the French in 2010, when he beat Andrey Golubev.)  Today he won while giving up only five.

Finally, to reach such a scoreline, Isner broke serve a total of six times.  That’s something else he’s never done before.  He’s broken five times on a handful of occasions, but never six, unless he did so in Davis Cup, for which stats are more difficult to come by.

Still, it seems likely that Klizan played worse than Volandri did.  As you might imagine, Klizan has never lost quite so comprehensively, though he did turn in a similarly abysmal performance in New York three years ago, when he lost to Juan Carlos Ferrero, 6-1 6-3 6-0.

For Young, it was only his third straight-set victory at a slam, regardless of lopsidedness.  And it was only the third time he won a Grand Slam match having earned his way into the main draw.  His other five wins–all at the US Open–came as a wild card.

Since we’re talking about all these Americans winning in New York, it seems like a great time to point you toward Colin Davy’s recent effort to quantify home-court advantage in tennis.  He finds that home-country players–both men and women–have a slight advantage that cannot be explained by other factors, to the tune of about 2%.

In building jrank, I’ve done some work along the same lines, and arrived at a similar number.  (On my old blog, I posted some very crude attempts, not controlling for things like surface, and claimed a much bigger effect.  I don’t think I’ve published the details of my more recent efforts.)

As Colin notes, it’s a small effect compared to other sports. (Isner’s love of the USA notwithstanding.)  To the extent home-court advantage in tennis stems from officiating bias–a common cause in other sports–the increasing use of Hawkeye would seem to lessen the effect.  And oddly, the practice of putting local players on main courts would turn out to be counterproductive.  By putting locals on Hawkeye courts, you’re taking away at least one slight advantage.

Colin also suggests comparing different stages of the tournament, which may reveal that umpires have a greater or lesser bias as the stakes get higher.  That test occurred to me for a different reason.  Travel-related fatigue is a major factor (again, something Colin acknowledges), but it is one that would likely lessen as the tournament goes on.  A player might still be jetlagged for his first-round match, but if he wins a couple of rounds, that effect is likely gone.

It’s an interesting field of study, one that is particularly tricky to separate from others–such as travel effects, surface preferences, venue familiarity, and so on.  As is so often the case in tennis, it is a topic that has been extensively hashed out for other sports, yet barely researched in ours.

In case you missed it yesterday afternoon, I tracked every point of the Federer-Zemlja match, and came up with some very detailed serve breakdowns for each player.  Check it out.