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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.

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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.

fedbp

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.

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Barcelona or Bucharest? Scheduling Decisions Under the Microscope

This post has been withdrawn due to a mistake in the calculations that seriously affects its conclusions.  I am leaving this note here to avoid breaking the link.  Look on the bright side–on this site, there’s plenty of tennis analysis in which the mistakes have less serious effects.

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ATP Finals Outside the Top 100

Yesterday in the Delray Beach semifinals, Edouard Roger-Vasselin and Ernests Gulbis upset the top two seeds, John Isner and Tommy Haas.  Both are ranked outside the top 100, meaning that the final in Florida will be contested by two players who started the event far outside of contention.

As with most “gee whiz”-type tennis events, it’s not the first time.  In fact, there have been at least 59 ATP events since the inception of the ranking system in which both finalists were outside the top 100.  (I don’t have ranking data for 1982, so there may be more.)

However, this is the first such final since 2007, when the Houston final was contested between Ivo Karlovic and Mariano Zabaleta.  As you’ll see in the overall list, these finalists skew toward the Gulbis’s more than the Roger-Vasselins–while such players might have gone through injury or slumps, they often reached a much higher level at some other time.

Newport has been the most common scene of these sorts of finals.  Eight times in the event’s history has the final been played between two men outside of the top 100.  In fact, four of the last nine such finals have been at Newport.

Finally, these finals have become progressively rarer as the number of events on the ATP calendar shrinks and more top players compete in a higher percentage of ATP events.  (Even Delray Beach, this week notwithstanding.)  There were (at least) 25 finals like this in the 1980s, 17 in the 1990s, 10 in the 2000s, and so far just one in the 2010s.

Click here for a list of all of these finals.

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Point-by-Point Profile: Novak Djokovic

In the last few weeks, we’ve seen some overall serving trends–how righties and lefties perform in the deuce and ad courts, and how successful they are at specific point scores.

The tour-wide results are interesting enough, but there’s much more to discover at the individual player level. Because point-by-point data is only available for 2011 grand slam matches, only a few players have had enough points tracked to allow us to make meaningful conclusions. Fortunately, those are the best players in the game, and there’s plenty to discover.

Let’s start with Novak Djokovic. Much of his success seems to stem from rock-solid consistency: he can attack when returning almost as much as most players do on serve; he is strong on both forehand and backhand, and he rarely shows signs of mental weakness. If there is a player who doesn’t display the typical differences between deuce and ad courts and various point scores, it would seem to be Djokovic.

The first table shows the frequency of different outcomes in the deuce court, in the ad court, and on break point, relative to Djokovic’s average. For instance, the 1.018 in the upper left corner means that Djokovic wins 1.8% more points than average in the deuce court.

OUTCOME       Deuce     Ad  Break  
Point%        1.018  0.980  0.975  
                                   
Aces          1.117  0.869  1.046  
Svc Wnr       1.101  0.886  0.865  
Dbl Faults    1.176  0.802  1.102  
1st Sv In     1.028  0.968  1.081  
                                   
Server Wnr    1.027  0.970  0.815  
Server UE     0.973  1.030  0.941  
                                   
Return Wnr    0.972  1.031  2.125  
Returner Wnr  0.832  1.189  1.487  
Returner UE   0.927  1.082  1.092  
                                   
Rally Len     0.938  1.070  1.184 

There are some huge differences here. Given the gap between deuce and ad results for many types of outcomes, it’s surprising that Novak wins so many ad-court points. He hits nearly 12% more aces in the deuce court, suggesting that even when he doesn’t hit an ace or service winner, he better sets up the point. Returners are much more likely to hit winners against him in the ad court, and the point requires more shots.

There are even more extreme numbers on break point. It’s unclear from the numbers whether Djokovic consistently goes for more on the serve on break point–more aces, fewer service winners, more double faults, but more first serves in–but it appears he plays much more gingerly, hitting far fewer winners and allowing opponents to hit more than twice as many return winners than average.

Next, this is how he performs on a point-by-point basis. Win% shows what percentage of points he wins at that score; Exp is how many he would be expected to win (given how he performs in each match), and Rate is the difference between the two. A rate above 1 means he plays better on those points; below 1 is worse.

SCORE   Pts   Win%    Exp  Rate  
g0-0    360  70.0%  70.2%  1.00  
g0-15   107  65.4%  68.5%  0.96  
g0-30    37  59.5%  66.5%  0.89  
g0-40    15  66.7%  64.8%  1.03  
                                 
g15-0   248  66.5%  71.0%  0.94  
g15-15  153  69.9%  69.9%  1.00  
g15-30   68  67.6%  68.1%  0.99  
g15-40   32  68.8%  66.7%  1.03  
                                 
g30-0   165  67.3%  71.3%  0.94  
g30-15  161  70.2%  70.4%  1.00  
g30-30   94  77.7%  67.9%  1.14  
g30-40   43  62.8%  66.4%  0.95  
                                 
g40-0   111  73.9%  72.0%  1.03  
g40-15  142  76.8%  71.3%  1.08  
g40-30  106  67.0%  68.6%  0.98  
g40-40  104  72.1%  66.8%  1.08  
                                 
g40-AD   29  69.0%  66.2%  1.04  
gAD-40   75  70.7%  67.0%  1.05  

It appears that Djokovic’s caution on break point isn’t hurting him; despite losing a point or two more than expected at 30-40, he gets it back at 40-AD. Novak excels most in the pressure points: 30-30 and 40-40, with strong showings at nearly every point from 30-30 on, with the exception of 30-40–which may just be a fluke–we only have 43 points to work with.

We can go through the same exercises for Djokovic’s return points. The next two tables are trickier to read. Look at them as Serving against Djokovic. Thus, the number in the upper-left corner means that when serving against Djokovic, players win 1% more points than average in the deuce court.

(I’ve excluded return points against lefty servers, including Nadal. Since lefties and righties have such different serving tendencies, limiting the sample to righty servers gives us clearer results, even as the sample shrinks a bit.)

OUTCOME       Deuce     Ad  Break  
Point%        1.010  0.989  1.023  
                                   
Aces          1.024  0.974  1.091  
Svc Wnr       0.998  1.002  1.105  
Dbl Faults    0.994  1.007  0.986  
1st Sv In     1.055  0.940  0.957  
                                   
Server Wnr    1.002  0.998  1.091  
Server UE     0.987  1.015  0.964  
                                   
Return Wnr    1.123  0.867  0.849  
Returner Wnr  0.895  1.114  1.124  
Returner UE   0.858  1.153  1.069  
                                   
Rally Len     0.992  1.009  0.959  

It seems that Novak goes big on the return in the deuce court, but tries to do more later in ad-court points. The break point tendencies may speak to other players’ fear of Djokovic’s return game: They go bigger with their serve, hitting more aces and service winners, and severely limiting Novak’s return winners. In the end, though, it doesn’t matter: he converts the break points anyway.

Here’s more on Djokovic’s return game, again with numbers from the perspective of players serving against him.

SCORE   Pts   Win%    Exp  Rate  
g0-0    346  58.7%  56.3%  1.04  
g0-15   143  53.1%  55.1%  0.96  
g0-30    67  52.2%  53.9%  0.97  
g0-40    32  53.1%  53.0%  1.00  
                                 
g15-0   198  62.1%  57.2%  1.09  
g15-15  151  54.3%  56.0%  0.97  
g15-30  104  45.2%  54.7%  0.83  
g15-40   74  59.5%  53.4%  1.11  
                                 
g30-0   123  60.2%  58.1%  1.04  
g30-15  131  51.9%  56.9%  0.91  
g30-30  110  60.0%  56.0%  1.07  
g30-40   88  54.5%  54.3%  1.00  
                                 
g40-0    74  64.9%  59.0%  1.10  
g40-15   94  61.7%  57.5%  1.07  
g40-30  102  53.9%  57.2%  0.94  
g40-40  189  50.8%  55.4%  0.92  
                                 
g40-AD   93  54.8%  54.3%  1.01  
gAD-40   96  55.2%  56.4%  0.98  

While Djokovic excels at deuce (servers should win 55.4% of those points; they manage to win only 50.8%), the reverse happens at 30-30. There aren’t many clear trends here, which may simply attest to Djokovic’s return dominance, regardless of point score.

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Thursday Topspin: Capitalizing

Open quarters: Of the eight men left standing in Barcelona, five are seeded in the top eight.  The other three are unseeded, but only one needed to pull a major upset to get to the quarters.

That man is Ivan Dodig, who took out Robin Soderling in the 2nd round, allowing the Swede only six games.  It’s been a breakthrough season for the Croatian, who will crack the top 50 thanks to his performance this week.  He backed up the 2nd-round win with a tough three-setter against Milos Raonic today.  Perhaps most impressive, he reeled off seven points in a row to win a first-set tiebreak.

Dodig has an opportunity to go even further, as the man seeded to face him in the quarters was Tomas Berdych, who withdrew.  Instead, his next opponent is Feliciano Lopez, who defeated Kei Nishikori today, after upsetting Guillermo Garcia-Lopez yesterday.  Thus, at least one semifinalist will be unseeded.

That man will almost certainly face Rafael Nadal in the semis.  Nadal, as goes without saying, breezed through his match today against Santiago Giraldo–if anything, it’s surprising that he failed to win 60% of total points.  Nadal’s quarterfinal opponent is Gael Monfils, who won in straight sets over Richard Gasquet–a positive result for Monfils, who just scraped by Robin Haase in the second round.

Predictions: There aren’t betting lines yet for all of the quarterfinals, but I have run my algorithm to get percentages for tomorrow’s four matches:

  • Nadal vs. Monfils: Oddsmakers have the Frenchman at 30-1, which seems excessive to me.  Yes, of course, Rafa is the heavy favorite, and yes, of course, Gael could self-destruct and play no better than Giraldo did today.  But on the other hand, Monfils is one of the few men with a game that could–if the stars aligned exactly right–beat Nadal on clay.  My system gives Gael a 20% chance, which as I’ve commented before, is just a reflection of how my system doesn’t know what to do with someone so surface-dominant as Nadal.
  • Dodig vs. Lopez: After beating Soderling, Dodig will no doubt gain several places in my ranking system, but that won’t happen until next Monday.  As it is now, my algorithm isn’t too impressed, especially with Dodig’s potential on clay.  It gives Feliciano a 64% chance of reaching the semis.
  • Jurgen Melzer vs. David Ferrer: Even after Melzer’s impressive victory over Roger Federer last week, Ferrer is still the favorite here.  I have him at 60.5%, while early sportsbook odds set him at 77%.
  • Nicholas Almagro vs. Juan Carlos Ferrero: It’s nice to see Ferrero right back in the mix, even if it took some good fortune to get him there.  In fact, he just barely got by Simone Vagnozzi today, a result that must have Almagro licking his lips in anticipation.  Early sportsbook odds have Almagro at 78%, while my system puts him at 70%.

Streaking southpaw: Thomas Schoorel isn’t letting up–after winning a title last week, he hasn’t lost a set this week, including his opening-round upset of Jeremy Chardy.  Tomorrow he’ll face 5th-seed Ivo Minarin the semis.

Another man to watch on the challenger tour is Aljaz Bedene, the Slovenian who won his first title at this level three weeks ago in Barletta.  Last week he reached the semifinals in Blumenau, and he’s in another quarter in Santos, where he’ll next face 5th-seed Diego Junquiera.

See you tomorrow!

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