The Odds of Breaking Back

Perhaps the most unquestioned piece of conventional wisdom in tennis is this: after breaking serve, a player is particularly vulnerable to being broken himself.  It certainly seems to be true–to take just one example, in the Isner/Karlovic match last week, there were only two breaks of serve, and they were consecutive.

As with most bits of conventional wisdom, it’s not clear exactly what people mean by it.  When Djokovic crushes someone 6-0 6-1, do we really think his serve is more vulnerable after each of his five or six breaks than it is after the one game his opponent holds?  When a player does break back, is he then more vulnerable in his next service game?

Today, I’ll try to address the more basic versions of the cliche.  The results are a bit surprising.

The dataset

I’m working with all of the 2011 Australian Open matches from courts where Hawkeye was in place.  That’s about 80 of the men’s singles matches, and roughly the same number of women’s matches.  I’ve run the numbers on both genders but will keep them separate, for reasons that will become clear.

These matches give us over 2,700 men’s games across about 300 sets, and nearly 2,000 women’s games over a bit more than 200 sets.

Breaking back: Men

At this year’s Aussie Open, 24% of all men’s games were service breaks.  If we take the conventional wisdom literally, we would hypothesize that in the game following a service break, another break would occur more than 24% of the time.

But it doesn’t.  In the game following a service break, the server is broken only 19.5% of the time.  (I’m excluding service breaks that end a set or take a set to a tiebreak.)  In other words, in the aggregate, a player is more likely to hold serve after breaking serve than he is after his opponent holds.

Of course, as I suggested by mentioning Djokovic a moment ago, there’s a huge selection bias here.  A player who breaks serve is (all else equal) likely to be a better player than one who doesn’t.  The best players in the most lopsided matches are breaking serve frequently, and because they are the better player, it makes sense that they are more likely (again, all else equal) to hold their own serve.

Without looking at individual matchups, it’s not immediately clear how to address this problem.  For one thing, I’m not convinced it’s a problem.  When Federer broke Kohlschreiber today, a commentator may have said, “Roger is particularly vulnerable here, let’s see if he can consolidate the break.”  One could easily respond: “Roger just showed us he’s in tremendous form; the very fact he just broke serve is an indication that he’s less vulnerable than usual on serve right now.”  And so it proved: Roger broke four times; Kohlschreiber never broke back.

What might be more instructive is to look at situations where the player who broke serve is considered to be roughly equal or inferior to his opponent.  Had Kohlschreiber broken serve early in the match, even given the assumption that he must be playing well in order to do so, the conventional wisdom would suggest that Federer is more likely to break back.  Perhaps that’s true.  It’s not something I can answer today–quantifying the matchups is beyond the scope of this afternoon project.  It’s also problematic in that it would also shrink the size of our already-small dataset.

In any event, it is clear that we can’t take this bit of conventional wisdom at face value.  It may be true in certain scenarios–some players may crumple under the pressure of consolidating a break, and others may rise to the occasion after losing serve.  But it is wrong to say that, in general, players are more vulnerable on serve after a break.

Breaking back: Women

As you might expect, breaks of serve are more prevalent in the women’s game, as are breaks-following-breaks.

At the 2011 AO, women broke serve 36.5% of the time.  In games following breaks of serve, they broke 36.0%.  In contrast to the men’s results, this suggests that in the women’s game, a service break doesn’t tell us as much about the strength of the player who has accomplished the break–or, if it does, that a server is more vulnerable after breaking serve.  Anecdotally, it certainly seems that differences in mental strength play a larger role in WTA matches, so I would expect that the break-back rate would be higher.

As I’ve said, this is far from the final word.  As usual, the conventional wisdom masks many subtleties that only further analysis can unearth.

Tuesday Topspin: Federer Cruising

Kohl down: A couple of days ago, I suggested that Roger Federer might have his hands full with a second-round matchup against Philipp Kohlschreiber.  While Kohlschreiber looked great in Indian Wells, knocking out Robin Soderling and nearly upsetting Juan Martin del Potro, he didn’t do much to justify my optimism this week.  He just barely made it past Andrey Golubev, and earlier today, lost to Federer, winning only three games and 36% of total points.

Federer has gotten a head start on the pack, becoming the first man into the round of 16, and one of only two of the top eight seeds in action today.  (The other is Tomas Berdych, who will take on Olivier Rochus later.)  Federer’s section of the draw is distinctly unchallenging; his likely next opponent is Marin Cilic, and after that, he’s seeded to play Jurgen Melzer (or, very possibly Nicholas Almagro).  If he reaches the semifinal, we could be treated to an interesting contrast of clay-court styles, as his probable opponent is either David Ferrer or Fernando Verdasco.

Sets up: There haven’t been a lot of upsets so far in the first round, but a slew of matches have gotten interesting.  Among yesterday’s 13 first-rounders, 7 went to a deciding set.  Already today, three more have done so, including the clash between Feliciano Lopez and Janko Tipsarevic, which Lopez won in a third-set tiebreak.  Ivan Ljubicic has just taken the first set from Jo-Wilfriend Tsonga, which means we’ll either see an upset or yet another three-setter.

A fascinating match still on tap for today is a second-rounder between Ernests Gulbis and Milos Raonic.  As I mentioned yesterday, Gulbis had an excellent clay season last year, even if his dreadful recent results tend to camouflage them.  Raonic, of course, has virtually no history on the surface, yet it didn’t stop him from advancing past Michael Llodra.  Oddsmakers give Gulbis a 67% chance of winning, which is almost exactly what my system says, as well.

Five challengers: Thanks to the small Monte Carlo draw, plenty of top-100 players are contesting challengers this week.  There are five of them, meaning that the talent is spread fairly thin.  As I noted over the weekend, the top tourney is in Rome, where a handful of youngsters are in the field.  That event has already seen a major upset, as Serbian qualifier Boris Pashanski knocked out #2 seed Bjorn Phau.  Top seed Andreas Haider-Maurer also has his hands full with an opening matchup against Uladzimir Ignatik.

In Athens, the field is not as strong, but two good players anchor the draw.  Benjamin Becker is the top seed, while Dmitri Tursunov is #2.  In Brazil, the tournament in Blumenau keeps the South American clay circuit going.  Tiago Fernandes, the surprise finalist last week, is in the draw, as are the winners from two weeks ago in Barletta and Barranquilla, Aljaz Bedene and Facundo Bagnis.  There’s also plenty of experience there, as the field includes Martin Vassallo Arguello, Jose Acasuso, and Nicholas Massu.

Plenty of notable Americans are playing at the Tallahassee event, including wild card James Blake and fourth-seed Ryan Sweeting.  Also of interest is a first-round match between wild cards Denis Kudla and Michael Shabaz, as well as the presence of Wayne Odesnik, who qualified.  Finally, Dustin Brown highlights the field in Johannesburg, the weakest of the five events at this level.  Clearly, there will be plenty of tennis to follow this week.

See you tomorrow!

Monday Topspin: First-timers

New titlists: We have two first-time champions on the ATP tour: Pablo Andujar and Ryan Sweeting.  Andujar got better as the week went on in Casablanca, going three sets in the first round against Florent Serra, to a tiebreak against Jeremy Chardy in the second, and finally disposing of Potito Starace 6-1 6-2 in yesterday’s final.  He is definitely a man to watch over the next two months; he’ll next play in Barcelona.

Sweeting was the upset winner over Kei Nishikori in Houston, surprising just about everybody by playing so well on clay.  It was a very close match: the American won 51% of total points, and a lower percentage of service points than his opponent did.  Nishikori may be the more heralded prospect, but Sweeting is working his way up the scale.

New rankings: Champions Andujar and Sweeting are two of the biggest gainers in this week’s rankings, as both ascend to new career highs.  Andujar rises to #52, Sweeting to #67.  Also notable is Nishikori’s jump to #48, also a personal best for him.

The biggest losers are last year’s titlists in Casabalanca and Houston: Stanislas Wawrinka and Juan Ignacio Chela, neither of whom played this week.  Wawrinka drops two spots to #15, while Chela crashes 14 places to #42.

Challenger winners last week were Julian Reister, who breaks into the top 100 for the first time, Tatsuma Ito, who defeated the weak field in Recife, and Paolo Lorenzi, winner in Pereira.  Also of note is Tiago Fernandes, a wild card who reached the final in Recife before he withdrew.  His three-set battle with Julio Silva in the semifinals helped him jump 129 ranking points to #380.

Monte Carlo: If you missed them yesterday, be sure to check out the results of my Monte Carlo simulation.  My clay rankings are in many ways more interesting than the hard court rankings, since they differ so much more from the standard ATP list.

A couple interesting examples of the difference have already been on display.  Yesterday, oddsmakers heavily favored Alexandr Dolgopolov over Ernests Gulbis, only to see the higher-ranked Dolgo lose in straight sets.  By contrast, my system recognizes his three straight quarterfinal appearances in last year’s clay season, including a win over Roger Federer.  Accordingly, it saw the Gulbis win coming, giving the Latvian a 67% chance of advancing.

Here’s another one: Olivier Rochus just snuck by Chela in three sets.  Sportsbooks gave Chela a roughly 65% chance of winning, while my predictions set him at a more modest 54%.  Rochus has had plenty of success on clay, especially at the challenger level, while my system sees Chela as somewhat overrated on the surface.

Of course, we could cherry-pick all day, and we’d be sure to find plenty of examples where my system went wrong.  All I want to highlight is that predicting clay court results is tricky, and it’s easy to give too much weight to recent results (Dolgopolov) or clay reputation (Chela).

In addition to the two matches I’ve already mentioned, today has already seen a notable upset: Florian Mayer over Mikhail Youzhny.  It’s another strong step forward for Mayer, and a couple more wins on clay will get him in position for a seed at Roland Garros.  It’s an equally strong sign for Youzhny, who has seen his results yo-yo over the last few years.  His only strong showing so far in 2011 was a victory over Jo-Wilfried Tsonga back in February.

See you tomorrow!

Monte Carlo Projections

Clay court rankings and projections are tough.  Most of the top 50 ATP players only compete on clay for a couple months of the year, so at the beginning of the clay-court swing, we’re using surface-specific results from almost a year ago; at the end, we’re depending heavily on each player’s recent results.

Of course, the very top of the list is easy.  Rafael Nadal hasn’t lost a clay court match since the 2009 French Open.  It gets messy soon after that, since Nadal left the rest of the field fighting for crumbs.  Roger Federer is the clear #2 in this field, with Andy Murray a distant third.  (And maybe he should be even more distant.)

These projections are clay-specific, as you can probably tell by some of the percentages.  My clay rankings, however, are heavily regressed back to overall rankings so, for instance, Milos Raonic gets plenty of credit for his recent success on hard courts.  (And today he justified that credit.)

The tournament organizers made it tough for me to do pure projections, since four main draw matches were complete by the time qualifiers were placed.  Thus, the numbers are below are done as if I didn’t know anything about the outcome of today’s main draw matches.  I used rankings generated last Monday, so I might be selling Potito Starace (and, to a lesser extent, Victor Hanescu) a little short by excluding results from Casablanca.

Enjoy!

 

Player                   R32   R16    QF    SF     F     W
(1)Rafael Nadal         100% 92.7% 79.9% 66.8% 52.4% 36.6%
(q)Julien Benneteau      54%  4.4%  1.7%  0.6%  0.2%  0.0%
Jarkko Nieminen          46%  2.9%  1.0%  0.3%  0.1%  0.0%
(q)Vincent Millot        26%  5.6%  0.3%  0.1%  0.0%  0.0%
Guillermo Garcia-Lopez   74% 31.8%  5.5%  2.1%  0.7%  0.2%
Denis Istomin            27% 12.8%  1.3%  0.4%  0.1%  0.0%
(13)Richard Gasquet      73% 49.8% 10.3%  5.3%  2.4%  0.9% 

Player                   R32   R16    QF    SF     F     W
(12)Jo-Wilfried Tsonga   59% 35.2% 17.0%  4.0%  1.7%  0.6%
Juan Monaco              41% 21.6%  8.9%  1.8%  0.7%  0.2%
Ivan Ljubicic            55% 25.5% 10.5%  2.2%  0.9%  0.2%
Jeremy Chardy            45% 17.7%  6.3%  1.1%  0.3%  0.1%
(q)Olivier Rochus        46%  8.7%  2.6%  0.3%  0.1%  0.0%
Juan Ignacio Chela       54% 12.4%  4.2%  0.6%  0.1%  0.0%
(5)(WC)Tomas Berdych    100% 78.9% 50.5% 14.7%  7.8%  3.2% 

Player                   R32   R16    QF    SF     F     W
(3)(WC)Andy Murray      100% 70.6% 54.3% 38.4% 16.5%  8.7%
(WC)Radek Stepanek       30%  5.9%  2.5%  0.9%  0.2%  0.0%
Marcos Baghdatis         70% 23.5% 14.5%  7.8%  2.3%  0.8%
Albert Montanes          64% 30.9%  8.9%  4.0%  0.8%  0.2%
Xavier Malisse           36% 11.1%  2.0%  0.6%  0.1%  0.0%
Thomaz Bellucci          52% 30.9% 10.1%  4.7%  1.1%  0.3%
(16)Gilles Simon         48% 27.0%  7.7%  3.4%  0.7%  0.2% 

Player                   R32   R16    QF    SF     F     W
(10)Mikhail Youzhny      52% 38.1% 18.3%  7.0%  1.7%  0.5%
Florian Mayer            48% 33.3% 13.8%  4.8%  1.1%  0.3%
(q)Frederico Gil         41% 10.2%  2.1%  0.3%  0.0%  0.0%
Sergiy Stakhovsky        59% 18.4%  5.0%  1.1%  0.1%  0.0%
Daniel Gimeno-Traver     40%  7.9%  2.9%  0.5%  0.1%  0.0%
Santiago Giraldo         60% 15.6%  6.6%  1.8%  0.2%  0.1%
(8)Gael Monfils         100% 76.5% 51.3% 24.7%  7.7%  3.0% 

Player                   R32   R16    QF    SF     F     W
(6)Fernando Verdasco    100% 71.3% 54.5% 31.0% 13.6%  5.2%
Tommy Robredo            73% 24.6% 15.1%  5.7%  1.6%  0.4%
Ivan Dodig               27%  4.0%  1.5%  0.3%  0.0%  0.0%
Kevin Anderson           44% 16.8%  3.4%  0.7%  0.1%  0.0%
Fabio Fognini            56% 24.1%  6.0%  1.5%  0.3%  0.0%
(WC)Jean-Rene Lisnard    14%  3.4%  0.3%  0.0%  0.0%  0.0%
(11)Viktor Troicki       86% 55.6% 19.2%  6.5%  1.7%  0.4% 

Player                   R32   R16    QF    SF     F     W
Ernests Gulbis           67% 44.8% 22.0% 12.2%  5.0%  1.8%
(14)Alexandr Dolgopolov  33% 16.9%  5.5%  2.2%  0.6%  0.1%
Milos Raonic             59% 24.4%  8.8%  3.9%  1.1%  0.3%
Michael Llodra           41% 13.9%  4.1%  1.4%  0.3%  0.1%
Janko Tipsarevic         55% 13.5%  5.3%  1.9%  0.4%  0.1%
Feliciano Lopez          45% 10.7%  3.7%  1.2%  0.3%  0.0%
(4)David Ferrer         100% 75.8% 50.7% 31.4% 14.3%  6.0% 

Player                   R32   R16    QF    SF     F     W
(7)Jurgen Melzer        100% 54.7% 29.3%  9.3%  4.2%  1.3%
Nikolay Davydenko        72% 37.5% 20.3%  6.8%  3.2%  1.1%
Robin Haase              28%  7.8%  2.6%  0.5%  0.1%  0.0%
(q)Maximo Gonzalez       55% 12.3%  2.8%  0.3%  0.1%  0.0%
Victor Hanescu           45%  8.6%  1.8%  0.2%  0.0%  0.0%
Marcel Granollers        16%  8.5%  2.1%  0.3%  0.1%  0.0%
(9)Nicolas Almagro       84% 70.5% 41.1% 15.2%  7.7%  2.8% 

Player                   R32   R16    QF    SF     F     W
(15)Marin Cilic          86% 68.2% 19.9% 10.4%  4.8%  1.5%
(q)Filippo Volandri      14%  5.7%  0.6%  0.1%  0.0%  0.0%
(q)Pere Riba             43%  9.7%  1.0%  0.2%  0.0%  0.0%
Potito Starace           57% 16.4%  1.7%  0.3%  0.1%  0.0%
Philipp Kohlschreiber    61% 11.6%  6.4%  3.0%  1.2%  0.3%
Andrey Golubev           39%  5.2%  2.4%  0.9%  0.3%  0.1%
(2)Roger Federer        100% 83.2% 68.1% 52.6% 39.0% 22.1%

Sunday Topspin: Missing the Cut

Milos on clay: The Monte Carlo draw isn’t entirely set, with a few qualifying matches left to play, but the first round is already underway.  Hometown hero Ivan Ljubicic kicked things off with a 6-1 6-2 trouncing of Jeremy Chardy, and Milos Raonic has just won his first ATP-level match on clay against Michael Llodra.

And a weird, weird match it was.  Unfortunately the ATP website doesn’t appear to have posted stats for the match; we’ll have to stick with “weird” based only on the final score of 6-3 0-6 6-0.  Raonic displayed some inconsistency at Indian Wells, and it’s easy to imagine Llodra posting a result like this.

Still, it’s a good start for the Canadian.  With no points to defend, even a modest level of success in the clay season will keep him heading up the rankings.  Next, he’ll face either Alexandr Dolgopolov or Ernests Gulbis.

ATP finals: Today, Potito Starace plays Pablo Andujar for the championship in Casablanca.  After that match, Starace is slated to head to Monte Carlo for an opening round match against a qualifier.  What makes this noteworthy is that, among the four finalists this week, Starace is the only one who even made the cut for the main draw in Monte Carlo.  Andujar intended to play qualifying before his success this week prevented it.

Starace just barely got past Victor Hanescu to reach the final, needing a third-set tiebreak to do so.  Andujar’s semi, against top seed Albert Montanes, was just as topsy-turvy, despite the more pedestrian score of 6-4 6-4.  The match included 29 break points, including 16 chances for Montanes.  Alas, Montanes only seized three chances while Andujar took advantage of 5 of 13, and that was the difference.

Oddsmakers give Starace the edge here, with about a 57% chance of winning.  Based solely on rankings and results, the Italian is better than that.  But Andujar’s recent results suggest he could be primed for the upset.

In Houston, the final will be decided between Kei Nishikori and Ryan Sweeting.  Both won yesterday in straight sets, Sweeting out-serving Ivo Karlovic to accomplish the feat.  Nishikori got past Pablo Cuevas despite missing more than half of his first serves.  Cuevas was more successful with his first offerings, but he won only half of his service points, a rate that isn’t going to win you any matches, no matter what the surface.

Normally, the appearance of a wild card in the final of an ATP-level event would be attention-grabbing.  Given the results of U.S. tournaments so far this year, it’s getting to be a habit.  Raonic reached the final in Memphis on a wild card, and Juan Martin del Potro, also on a WC, came one match short of the same mark.

As great a story as it would be if Sweeting won his first ATP title, the odds are against it.  Sportsbooks suggest that Nishikori has a 69% chance of winning today, and my clay rankings say 73%.  Nishikori has had the superior tournament, as well, knocking out the top seed Mardy Fish as well as two guys, Cuevas and Igor Andreev, who can be formidable on clay.

When in Rome: One more note for today.  The main draw for next week’s Rome challenger is set, and it’s one of the strongest challenger-level fields of the year, including many of the young players who have excelled so far this season.

Cedrik-Marcel Stebe came through qualifying (the last time he’ll have to do so at this level, I hope), and will face what, sadly, is a cupcake draw: yet another wild card appearance for Thomas Muster.  Stebe’s nemesis from the Asian swing, Uladzimir Ignatik, got the opposite treatment, as he’ll begin his tournament against top seed Andreas Haider-Maurer.  Also in the draw are youngsters-to-watch Evgeny Donskoy, Thomas Schoorel, and Martin Klizan.

As soon as the qualifiers are placed in the Monte Carlo draw, I’ll post some tournament odds.  That’ will probably be later today, so be sure to check back in.

Saturday Topspin: Tiebreak Monster

“Tennis:” I’m glad that yesterday’s match between Ivo Karlovic and John Isner wasn’t televised.  It made me angry just checking the score occasionally.  The best part about a quarterfinal between these two one-dimensional players?  One of them had to lose.

Ok, that’s a little harsh.  Based on the stats the ATP dribbles out to us, Isner served more cleanly, allowing only one break point.  Karlovic allowed 11–amazingly, the players traded breaks of serve in the second set–and didn’t serve as consistently as Isner did.

In a match like this, however, the numbers don’t matter for much.  It all came down to a third-set tiebreak, and there, Karlovic was a tiny bit better.  Final score: 7-6(2) 6-7(2) 7-6(9).  Good riddance.

It wasn’t all bad for Isner–he came back with Sam Querrey to win a doubles semifinal against Eric Butorac and Jean-Julien Rojer.  Isner and Querrey will face the Bryan brothers in the final.

Backing it up: On a day when Karlovic, Isner, Ryan Sweeting, and Mardy Fish all played, it’s surprising to say that the dominant serving performance of the quarterfinals belonged to … Kei Nishikori.  He won a higher percentage of service points than any one else in the round, and he won an astounding 22 of 23 points when his first offering went in.

Nishikori simply dismantled Fish in the only straight-set victory of the day.  Even if he loses today, he’ll jump to a new career high ranking of #53; if he wins the semifinal match, he’ll crack the top 50 for the first time.

Matchups: Nishikori will play Pablo Cuevas, the only other seeded player left in the draw.  Cuevas dropped his first set yesterday to Guillermo Garcia-Lopez but came charging back despite missing more than half of his first serves.  The oddsmakers have Cuevas as the very slight favorite there; my rankings give Nishikori a substantial edge.

The other semi pits Karlovic against Sweeting.  If nothing else, the pairing guarantees a rarity of some kind in Sunday’s final.  Either a qualifier (Ivo) or a wild card (Sweeting) will play for the championship.  Here, sportsbooks are much more confident, suggesting that Karlovic has about a 65% chance of winning.    My system is a little more favorable to the American, but still puts Ivo’s chances around 60%.

Elsewhere: Despite some early upsets, three of the four semifinalists in Casablanca are seeds; top seed Albert Montanes is starting his match against Pablo Andujar as I write.  It may be time to follow Andujar more closely–he beat Fernando Verdasco in Miami for his first major hard-court accomplishment, and he’ll ascend to a career high around #65 even if he loses today.

The other spot in the finals will be determined between Potito Starace and Victor Hanescu–it’s a particularly important match for the Romanian as he defends his finalist points from last year.

Yesterday I wrote about the cheap points available at the Recife challenger.  Tiago Fernandes won the quarterfinal between wild cards, and today he’ll face his first opponent of the tournament inside the top #500.  Julio Silva, the man he’ll play today, is no world-beater, but the odds strongly suggest that he’s a Fernandes-beater.  (There are some betting lines on the match, and surprisingly, Silva is given only a 70% chance of winning.)

Still, Fernandes will get 29 ranking points for his efforts, more than is given to the winner of most futures events.  And it’s arguable that he has even played a futures-level draw.

Monte Carlo: Qualifying in Monaco is underway, and the draw is out.  Novak Djokovic withdrew, but that still leaves eight of the top ten ranked players in the world–only Djokovic and Robin Soderling aren’t playing.

I’ll cover that in more depth tomorrow.  For now, it’s worth mentioning that Roger Federer’s possible second-round opponent is Philipp Kohlschreiber, a man who might be playing well enough these days to make for an early upset.

In the meantime, I’m shaping up my clay-court rankings.  Once the qualifers are placed, I’ll post my tournament odds.  In other words, you can look forward to a Monte Carlo simulation of the Monte Carlo Masters.

See you tomorrow!

Friday Topspin: Cheap Points

Easy going: I mentioned earlier in the week that the Recife challenger has a particularly weak field, with a cut over 400 and a top seed ranked #147.  As you might expect, most of the seeds are progressing easily–four of the top five are in the quarters.

It’s a mess at the top of the draw, though.  No one has benefited more than Brazilian wild card Tiago Fernandes.  Fernandes, ranked #509, drew German qualifier Lars Uebel.  Uebel is unranked, though he did beat two ranked players to get through qualifying.  But Uebel withdrew, leaving Fernandes to face lucky loser Tiago Lopes, ranked #534.

In the second round, Fernandes faced fellow local wild card Bruno Sant’Anna, another man without a ranking point to his name.  Now, in the quarters, he’ll face Guilherme Clezar, yet another Brailizian WC, ranked #724 in the world.  Clezar faced Marco Chiudinelli in the first round, winning a set before the Swiss retired.  Whichever of the wild cards wins today will receive the same number of points as the semifinalists in Monza, where just about everyone in the draw is superior to anyone left in Recife.

Colombia: Also in South America, the Pereira challenger is generating some interesting results.  I mentioned yesterday the success of local wild card Eduardo Struvay.  Another major upset in the second round came when young Argentine Facundo Bagnis knocked out Colombian top seed Alejandro Falla.  Bagnis won a challenger event last week and will ascend to at least #178 with this week’s result.

Today, Bagnis faces 5th-seeded Italian Paolo Lorenzi.  The oddsmakers have noticed the Argentine’s hot streak and give him about a 60% chance of advancing to the semis.

ATP: Finishing off the second round in Houston yesterday, all four matches went to the seeded player.  Pablo Cuevas didn’t mess around in getting past James Blake–he won 84% of service points, allowing the American only two break chances.

Cuevas’s opponent today is Guillermo Garcia-Lopez, winner of the latest ugly match in Houston.  GGL landed only 38% of his first serves, yet somehow allowed Somdev Devvarman only two break chances.  Devvarman converted both, but it wasn’t enough, as Garcia-Lopez broke five times, eventually winning 6-4 6-1.

The other winners yesterday were Kei Nishikori and Mardy Fish, both of whom advanced in straight sets, and will face each other today.  Given some of the serving performances in Houston, you have to wonder if there’s a strobe light just off center court.  In losing to Fish, Albert Ramos made only 44% of first serves; at least Nishikori and his opponent, Igor Andreev, were both comfortably above 60%.

That’s all I’ve got for today.  Monte Carlo (more important: televised matches from Monte Carlo) can’t arrive soon enough!

Thursday Topspin: 13 Feet, 5 Inches

Tall dudes: In a week where the best players are resting, at least the tallest players are in action.  In the round of 16 in Houston yesterday, both Ivo Karlovic and John Isner advanced, over Igor Kunitsyn and Horacio Zeballos, respectively.  You may be surprised, as I was, that neither match required a tiebreak.

Tomorrow, Karlovic and Isner will play each other, for 13 feet, 5 inches of service-domination ridiculousness.  Yesterday, Karlovic won a modest (for him) 71% of points on serve, though he lost only five times when his first offering went in.  Isner was more decisive, winning more than 80% of points on serve.  I really thought Zeballos would do better.

The two big men have played each other twice before, and their record is tied.  Isner won in Memphis last year, and Ivo was victorious back in 2008 in New Haven.  Both matches, of course, included a tiebreak.

Shorter dudes: The other two singles matches in Houston were upsets.  Ryan Sweeting once again beat his friend Sam Querrey, and Teymuraz Gabashvili defeated Grigor Dimitrov.  The latter match must have been a mess–17 double faults, and barely half of total points were won by the server.  Sure, it’s clay, but that’s just sloppy tennis.

Sloppy isn’t even the word for what happened to Querrey.  He had twenty-four break points, and converted only six of them.  I don’t know whether to give credit to Sweeting or criticize Querrey, but clearly somebody was reacting to the pressure.  To put that in perspective, Sweeting won almost exactly half of his service points when it wasn’t a break chance, but 75% when Querrey held a break point.

Sweeting and Gabashvili both have a big opportunity tomorrow, as they’ll face each other.  It would be Sweeting’s first ATP-level semifinal.

Casablanca: I continue to be unenthralled with this field, so I’ll focus on a young underdog, 20-year-old Andrey Kuznetsov.  Tomorrow he’ll face Victor Hanescu, the only seeded player to win a match yesterday.  His good week so far–three wins in qualifying and two so far in the main draw–will gain him at least 21 places in next week’s rankings, and a win over Hanescu would get him 16 more, putting him on the brink of cracking the top 200.

My other favorite 20-year-old Russian: The strongest Challenger field this week is in Monza; stacked with second-tier clay court specialists, the level of play probably isn’t much behind that of either of this week’s ATP events.

Both of the top two seeds in Monza have been eliminated, leaving two title contenders in their place at the top and bottom of the draw.  The man who took out top seed Jan Hajek is local boy Alessio di Mauro, a 33-year-old who reached the final in Casablanca’s challenger event a couple of months ago.  At the bottom of the draw is Evgeny Donskoy, the man who beat di Mauro in that final.

Another one to watch: The Colombians continue to fare well in their home event at Pereira.  Into the quarterfinals already are two locals, Juan Sebastian Cabal and Eduardo Struvay, while top seed Alejandro Falla plays his 2nd-round match today.

462nd-ranked Struvay, yet another 20-year-old, entered the event on a wild card.  He hasn’t advanced cheaply, beating two veterans: Martin Vassallo Arguello in the first round and Eric Prodon in the second.  Vassallo Arguello posted solid results after qualifying  last week, and Prodon is a clay specialist near his career high ranking.

Today: Mardy Fish will finally get underway in Houston, taking on the Spaniard Albert Ramos.  But first, James Blake will play Pablo Cuevas.  If Blake can beat Carlos Berlocq, he has a good shot against Cuevas, right?  Oddsmakers don’t think so, setting Blake’s chances at about 28%.

See you tomorrow!

Wednesday Topspin: Looking Up

Backtrack: If you haven’t read it yet, you should check out the piece I wrote yesterday afternoon about net-rushing, and the way we’ll someday be able to analyze the strategy.  There’s some great stuff in the comments, as well.

Feeling small: It was a rough day in Houston yesterday for Benjamin Becker.  The #5 seed lost his singles match to Ivo Karlovic, winning only eight return points.  Becker is the only seed to fall in the first round, and Ivo was the only qualifier to reach the round of 16.

It didn’t get any easier for Becker in the doubles.  Teaming with Igor Kunitsyn, he lost to John Isner and Sam Querrey in straight sets.  At least in that match he got a few break points.

More from Houston: Of the nine first-round singles matches yesterday, only one went to three sets.  That was the tilt between Carlos Berlocq and James Blake.  Berlocq won a first-set tiebreak before Blake came charging back, eventually winning 6-7 6-3 6-4.  The numbers from that match are positively bizarre.  Blake made only 47% of first serves, and faced twenty break points.  Berlocq only converted two of them.

Ryan Harrison had just as bad a day as Becker did.  He lost in straights to Horacio Zeballos, then dropped his doubles match against … Zeballos.  It will be interesting to see if Harrison is able to make any kind of statement on clay this year, as he won’t have the benefit of the wild cards he has received stateside.

Today’s schedule consists of the bottom half of the draw–four singles matches including Isner’s and Querrey’s.  Querrey will face a rematch of his Delray Beach loss against Ryan Sweeting, while Isner confronts Zeballos.  Karlovic should coast into the quarterfinals thanks to a matchup with Kunitsyn.

Getting interesting: I mentioned yesterday that the field is Casablanca isn’t very compelling.  A trio of upsets already today have lowered the quality, but perhaps they have made the event more interesting.

In three singles matches so far today, the 2nd, 4th, and 6th seeds have all lost.  #2 seed Marcos Baghdatis fell in three sets to 20-year-old Russian qualifier Andrey Kuznetsov, and #4 seed Andrey Golubev lost to Pere Riba after bagelling Riba in the first set.

8th seed Victor Hanescu plays Michael Berrer in a little while, and given the way things have gone so far today, he should be very concerned.

We’ll check back in with the challengers tomorrow–see you then!

Net-rushing, or The Stats We Don’t Have

In yesterday’s morning recap, I made the following comment about Nadal’s baseline game:

The one baffling thing is Nadal’s reluctance to come to net.   He was often standing right on the baseline, even hitting groundstrokes from a step inside the baseline.  Yet he almost never came forward unless forced.  Even with an imperfect net game, even against the passing-shot machine that is Djokovic, I think he would’ve been more successful taking advantage of some of those offensive positions.

In the comments, Tom Welsh laid out the flip side of the argument concisely:

During the Nadal-Djokovic match yesterday I noticed several occasions when each of those brilliant players came in to the net and was left looking like a hopeless beginner – either by a passing shot, or a sizzling ground stroke to the short ribs, or by a perfect lob landing just a couple of feet inside the baseline. I’m not tennis player, but it seems to me that no one can afford to come in these days unless the opponent is stretched to the breaking point. Even then, it’s taking a big risk.

That’s the argument in a nutshell.  Even more briefly:

  • PRO: Players should be more aggressive and come forward more often.
  • CON: In the modern-day game, approaching the net is usually too risky.

Which is it?

Pick your poison

The first thing that needs to be understood is that, against an elite tennis player, anything is a risk.  Short of a decisive smash, any shot you hit is likely to come back, and there’s a non-zero chance that what comes back is going to be a winner.  Choosing to come forward isn’t a decision between risk and no risk, it’s a matter of degree.

The main difference is that, if you come forward and fail, you’ll look like a fool, and your opponent will look brilliant, in the ways Tom described.  If you stay back and fail, it’s somehow more understandable–in a 15-stroke rally between top players, somebody has to lose.  Of course, you lose the point either way.

One of the problems of arguing this point with anecdotal evidence is that I think we, as both fans and players, remember the brilliant passing shots and jaw-dropping lobs.  If you rush the net and your opponent misses what would’ve been a sensational running forehand, you remember the amazing shot-that-almost-was.  Human brains don’t default to probabilistic calculations, while brilliant moments catch and keep our attention.

Commentators, steeped in strategy of the 70’s and 80’s, will always want too much net-rushing.  Most players will tend to stay back too much.  If we can ever establish the proper opportunities to come forward, the “correct” answer will turn out to be somewhere in between.

Where the stats fail

Answering the question analytically will be very difficult, and given the information currently out there, it’s flat-out impossible.

In the meantime, let’s think through what it would take to answer the question.  Starting with what I take to be the question itself:

Given his skillset, his opponent’s skillset, and each player’s position on the court, when should a player come forward?

That’s a lot of stuff we can’t quantify.  Even if we posit a couple of generic pro players, it’s still an unanswerable question.

Particularly useless are existing net stats.  Occasionally during a match, a broadcast will show us that so-and-so has won 5 out of 8 points at net.  The commentators reliably chime in, usually suggesting that the player has better net skills that we give him credit for (perhaps he’s been playing some doubles lately), and that he would benefit by coming in more.

In most cases, those 8 points couldn’t be less relevant.  Think back to Sunday’s Nadal-Djokovic match.  Much of the time Nadal came forward, it was in response to a Djokovic drop shot.  In other words, Nadal came forward on the defense!  I’m guessing he lost most of those points.  On the flip side, imagine Del Potro cracking a serve out wide, then coming in behind it to hit a swinging volley winner.  That’s 1-for-1 on the net point tally, but it doesn’t say a thing about Delpo’s deftness of touch around the net.

A framework

Let’s imagine that we suddenly had access to Hawkeye’s shot-by-shot data.  We’d know the hit point for every ball of every point of every match where the Hawkeye system was installed.  (Drool.)

If we knew that, we could come up with a fairly simple model to estimate the likelihood of winning a point from any position on the court, against a certain quality of shot.  Standing at the middle of the baseline smacking a 60 mph service return, you might have a 70% chance of winning the point.  Stuck in the backhand corner after your opponent has cracked a 90mph groundstroke, and it might be more like 20%.

The details of the model aren’t important.  What matters is that, with a certain data set, we could estimate the probability of winning a point given a variety of conditions.

Extending this framework to analyze a tactic like net-rushing wouldn’t be that complicated.  Let’s say Nadal is standing on the baseline with a 70% chance of winning the point.  No matter what he does afterward, he will probably hit a forehand into one corner or the other, after which we can once again estimate his probability of winning the point.  From there, he has two choices: Come forward, or stay back.  Some game theory might get involved, since his opponent will probably see him approach the net and may change his own strategy accordingly.

Again, we can work out the details when there is data to play with.  Given these relatively simple figures, we could estimate Nadal’s probability of winning the point coming forward behind his forehand and staying back after hitting the shot.

The numbers would give a better way of judging whether a particular play is advisable.  For Nadal, it may turn out that staying back is always smarter–after all, the numbers will probably tell us that, from any given position, he has a better chance than nearly anyone else of winning the point.  But, say, Ivo Karlovic may be better off coming in behind the exact same shot from the same position.  There’s a continuum between the extremes, of course, and we’ll need to know a lot more before we know what that looks like.

In the meantime, I’d still like to see Nadal come forward–and I’ll try harder to remember the times when his opponent goes for a blistering passing shot and misses.