Author: jsackmann

Rafael Nadal d. Novak Djokovic: Recap and Detailed Stats

There are a lot of words that can be used to describe Novak Djokovic, but “sloppy” usually isn’t one of them.  Despite plenty of brilliance from the Serbian, he made far too many mistakes to win today.  Of course, the man on the other side of the net, Rafael Nadal, may be the best in game at forcing his opponent to attempt low-percentage shots out of pure desperation.

This morning, I predicted that, in order to win the match, Nadal would need to serve well, piling up more quick service points than usual, as Djokovic is a master of neutralizing the server’s advantage.  Give him a few shots, and it doesn’t matter who delivered the serve or how well they hit it.

That isn’t what happened.  Nadal won fewer than one in five service points on or before his second shot.  (Djokovic did a little better by that metric, but at 21%, not by much.)  Instead, Rafa won the way Novak usually does: by neutralizing his opponent’s serve.

Rafa won 45% of return points today, a mark he has never before reached against Djokovic on hard courts.  Even more importantly, he won return points at the same rate when Djokovic was serving at 30-30 or later.  Djokovic won what would normally be an impressive number of return points: 38%.  In recent years on hard courts, that was always enough to beat the Spaniard.

It was a different kind of hard-court match today, one that was decided in grueling rallies.  20% of points played today reached at least ten strokes, and Rafa won 59% of them.  Of points that finished more quickly, Djokovic simply gave away too many.  By my unofficial (and rather strict) count, he hit over 60 unforced errors, more than double Nadal’s total.

Too many of those sloppy shots came at crucial moments.  A bad forehand miss on a mid-court sitter gave Nadal set point in the third set, which Rafa converted on the first try.  Serving down a break in the fourth at 1-4, Djokovic quickly went up 30-30, then missed his second shot on three straight points to give Nadal another break point.  At 30-0 in that game, it was possible to imagine Novak clawing his way back.  Once the double break was sealed, the match was over.

Djokovic showed plenty of brilliance, especially in the second and third sets, and contributed to some incredible tennis moments, including ten rallies that exceeded 20 shots.  Indeed, Djokovic converted a break chance by claiming the best of those, a 54-stroke slugfest in the second set (video here).  He didn’t go quietly until that dreadful game at 1-4.

By beating Djokovic at his own game, Nadal solidified his status as the most dominant player on hard courts.  His undefeated record on the surface this year didn’t leave that in much doubt, but it had been three years since he won a hard-court Grand Slam.  Assuming he stays healthy, even Rafa might agree that he heads to Australia as the player to beat.

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

Here is a complete win-probability graph, as well.

Djokovic-Nadal XXXVII: The (Actual) Keys to the Match

Both Rafael Nadal and Novak Djokovic have had easy routes to the US Open final.  Neither was tested before the semifinals, and neither has yet to play a top-eight opponent.  Yet both were pushed further than expected in their last matches.  Djokovic nearly lost in another tough five-setter against Stanislas Wawrinka, and Nadal looked almost human at times, spraying errors in his match with Richard Gasquet.

For all that, the field is down to the final two.  They’ve played 36 times before, with Nadal leading the career matchup 21-15. On hard courts, it is the 18th meeting, with Djokovic leading 11-6.  It is their eleventh encounter in a Grand Slam, of which Rafa has won seven of the previous ten, while they’ve split their two previous US Open finals.

Based on the most relevant pieces of this head-to-head–the last seven Djokovic-Nadal matches on hard courts, dating back to the 2010 US Open–we can identify some clear trends that tell us what to watch for, and what each player must do to seal the US Open title.

The key: Rafa’s service games

Of these last seven hard-court matches, Nadal has won three and Djokovic has won four.  If we could find some statistical indicators that each player reached when they won and failed to accomplish when they lost, we might be on to something.  Think of it like IBM’s Keys to the Match, but with actual predictive value.

Sure enough, there are plenty of indicators that fit the bill, and they almost all center on Nadal’s serve:

  • In four of the matches, Nadal has served fewer than 5% aces.  In the other three, at least 7% aces.  He lost all four of the former, and won all three of the latter.
  • In four of the matches, Nadal won fewer than 70% of his first-serve points.  In the other three, he won at least 71%.  He lost all four of the former, and won all three of the latter.
  • In three of the matches, Nadal won fewer than 47% of his second-serve points.  In the other four, won at least 56%.  He lost all of the former, and won all but one (the 2011 Indian Wells final) of the latter.

We can sum up the importance of Nadal’s service games from a more Djokovic-centered perspective:

  • In three of the matches, Djokovic won no more than 33% of return points.  In the other four, he won at least 37% of return points.  Care to guess which matches he won?

Djokovic’s service non-indicators

The numbers are not nearly so clear for Djokovic’s service games.  In the two meetings when Novak hit the most aces, Rafa won.  In three of the only four matches when Djokovic made 62% or more of his first serves, Rafa won.  (These are starting to sound like some of the more inane of the IBM keys.)

Generally, winning 65% of first serves is good enough for Novak to beat Nadal, except for last month’s match in Canada, when he won 71% of first serves and lost in a third-set tiebreak.  In Djokovic’s worst second-serve performance of the seven matches, the 2011 US Open final, he barely won 44% of those points, yet won the match.

Of course, this doesn’t mean that Djokovic’s service stats don’t matter.  It’s no accident that Novak’s first-serve percentages were much higher in the three sets he won against Wawrinka than in the two sets he lost.  On the contrary, Djokovic’s serve just isn’t as potentially dominant as Nadal’s is.

For example, in Saturday’s semifinals, Nadal won 36% of his service points on or before his second shot, while Djokovic won only 24% of his service points that way.  Nadal’s number isn’t staggeringly high (for example, both Kevin Anderson and Marcos Baghdatis topped 40% in that category in their second-round match) but it’s a number he can earn only when serving well.  When he isn’t earning those cheap, quick points against Djokovic, Novak takes away the server’s advantage, threatening to break in almost every service game.

By contrast, Djokovic–like Victoria Azarenka–doesn’t consistently earn that type of advantage on serve.  Sure, he gets some free points that way, but in general, he takes the slight advantage that serving confers and uses that as an edge in a longer rally.  In the semifinal against Wawrinka, his average service point–including aces and unreturnables–lasted more than five shots.

Getting one number for Novak

Individually, Djokovic’s service stats don’t tell us much.  But if we consolidate them into one number–Nadal’s return points won–we get a little better clue of what beating Novak requires.  In the three matches where Nadal failed to win 34% of return points, he lost.  In the two matches where he won at least 42% of return points, he won.

But if you’re counting, you’ve surely noted that I left out two matches.  In Montreal last month, Nadal won only 34.7% of return points, and won.  In the 2011 US Open final, he won 41.7% of return points, yet lost.  Djokovic can be so effective in his own return games–or simply unbeatable when given break point opportunities, like he was that day–that even a masterful return performance like Nadal displayed in that final isn’t always good enough.

So Novak’s numbers just aren’t as indicative as his opponent’s.  Instead, keep your eyes on Rafa’s serve statistics.  Despite the many long, gut-busting rallies we can expect this afternoon, Nadal has this match–like his previous hard-court meetings with the world #1–on his own racquet.

US Open Final: Serena Williams d. Victoria Azarenka: Recap and Detailed Stats

Today’s final was Serena Williams‘s for the taking.  She didn’t seize it as boldly as she might have, but she performed just well enough to overcome both the windy conditions and a reliably dogged opponent in Victoria Azarenka.

When Serena is playing as well as she did during the third set, it’s tough to see how she ever loses. But today we saw an excellent illustration of both her assets and her liabilities.  If her opponent can hang around in rallies, there will be enough errors to swing some matches in the other direction. Most of the WTA rank and file can’t absorb her pace and stick around long enough to reap the benefits of those errors, but Vika can.

And when Azarenka is playing her best, as she did on occasion throughout this match, she can attack on one of Serena’s less penetrating shots, creating opportunities for her own winners. A player with a bigger serve would do that with her serve; Vika must try to do so within each rally.

By the numbers, it’s a bit of a miracle that Vika forced a third set.  Twice in the second set, Serena served for the match and was broken.  It was a testament to Azarenka’s stubbornness, always putting one more ball back in play, forcing Serena to overcome both the pressure and the wind.  In that second set, Williams had a hard time doing that.

It was the wind–and Serena’s difficulty dealing with it–that kept this match going as long as it did.  While it made life difficult for both players at times, especially when playing on the right side of the chair, Serena struggled much more.  She never really adjusted to the conditions, setting up early and taking big swings when the wind was likely to move the ball a bit too much for that.  Many of Serena’s errors–especially her 33 unforced errors on the backhand side alone–can be attributed to that sloppiness.

By the third set, the wind had settled down and so had Serena.  Azarenka provided some help with two crucial double faults in the fourth game of the set, including one on break point.  It wasn’t her first poorly-timed double fault of the match–four of her five came at 30-30 or later–but this one was the beginning of the end.  Unlike in the second set, Serena didn’t let up.  She consolidated the break by holding to love, with an unreturnable, two aces, and a running backhand lob winner.

I wrote this morning that Azarenka’s chances hinged on her serve.  She won 54.5% of her service points, a bit less than she did against Serena in Cincinnati, but better than she did in each of her last three matches in New York.  Had she limited her double faults to less important moments, 54.5% may well have been enough.

In the end, Serena was simply too strong.  Vika is the very best on tour at what she does, negating the advantage of those huge weapons, but it allows her very little margin for error against Serena.  That margin for error wasn’t quite enough for her to pull off the upset today.

Here are the point-by-point-based serve, return, and shot-type stats for the match.

Does Azarenka Have a Chance?

The last two times Serena Williams and Victoria Azarenka have met on hard courts, Azarenka has come out on top.  As much confidence as that might give her going into today’s final, it might be the only evidence suggesting she’s likely to win.

Today’s match will come down to Vika’s ability to hold serve, and while she has moved quickly through her last two rounds, she has yet to show that she can serve well enough to hold off the onslaught that is Serena’s return game.

In the semifinal against Flavia Pennetta, she lost more service points than she won, and was broken in five of her nine service games.  Against Daniela Hantuchova, she lost 47% of her service points, suffering three service breaks.  Playing Ana Ivanovic, she lost more than half of her service points, and was broken seven times.

While each of those players had a nice tournament, this is not exactly a Hall of Fame lineup that has reduced Azarenka’s service games to coin flips.  None brings anywhere near the weaponry to the return game that Serena does.  And Serena is considerably more difficult to break back.

These numbers make it all the more surprising that the last meeting between these two players ended in Vika’s favor.  We have detailed data from that most recent matchup:  Azarenka managed to win 55% of her service points (the same figure she held Serena to) and landed 11 of 12 serves on game points, winning nine of them.

Another promising data point is last year’s US Open final, in which Serena managed to win only 44% of Azarenka’s service points.  In both of these recent contests, the differences between Vika’s first-serve and second-serve success rates is tiny–in New York last year, it was a mere two percentage points–suggesting that she needs only a slight edge at the beginning of a rally to win the point.

Azarenka has the ability to step up her game for the big matches, so the question she’ll have to answer today is: Can she serve more effectively than she has all tournament?  If she does, even at the modest level she did in Cincinnati, we’re in for a very competitive afternoon of tennis.

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Check out this final preview from Tom Perrotta, in which everyone agrees that Vika will raise her level today.

If you missed it yesterday, I wrote recaps of both men’s semifinals.  Djokovic-Wawrinka here, and Nadal-Gasquet here.  In those posts you can find links to my point-by-point based stats for both matches.

Finally, don’t miss this piece from Carl Bialik, in which he looks at IBM’s not-very-predictive “predictive analytics,” otherwise known as their Keys to the Match.  Next week, I’ll offer a closer look at the details of the better-performing “Sackmann Keys,” which, it turns out, have much more value for tennis analysis than merely showing up the folks at IBM.

Nadal d. Gasquet: Recap and Detailed Stats

Not often do we come away from a straight-set victory with newfound respect for the loser, but that’s the appropriate reaction today.

As I discussed this morning, Richard Gasquet has never accomplished much of anything against Rafael Nadal. The 10-0 head-to-head, if anything, disguises how lopsided it has been.

Today, for two sets, the Frenchman came as close to going toe-to-toe with Nadal as he probably ever will. From the start, he was playing a much more varied game than we are accustomed to from him, serving aggressively, rushing the net at any provocation, and even standing inside the stadium to return serve.

Despite getting broken three times, Gasquet never really went away. After he lost his first service game, it looked like another Nadal-administred drubbing in the works, but Richard held serve for the remainder of the set, finishing at 6-4.

In the second, he once again lost the first game of the set on serve, but went one better. He broke Nadal back, the first service game Nadal has lost in New York. Gasquet took advantage of Rafa’s carelessness to stay on serve until they reached a tiebreak.

Then came the disappointment of the match. Gasquet opened the breaker with a double fault, and serving at 1-6, he doubled once more. That was the only sign of the passive, unthreatening Richard we got all day.

The third set was more lopsided, though Gasquet kept playing aggressive tennis. Nadal was just too good. (Gasquet didn’t help, double faulting twice from 30-30 in the final game, but in the end, it was just the difference between 6-2 and 6-3.)

For Gasquet to beat Rafa, he would have to play the match of a lifetime. He didn’t come close to doing that today, but he did show up with a better set of tactics than he generally brings to bear. While a more varied attack from the Frenchman won’t earn him a spot in the top five, it will ensure he remains in the top ten.

Here are the complete point-by-point stats for the match, and in case you missed it earlier, here’s my recap of the Djokovic-Wawrinka semifinal.

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.

The Impossible Cases for Gasquet and Wawrinka

The last eleven times Stanislas Wawrinka has played Novak Djokovic, he has lost.  The last ten times Richard Gasquet has played Rafael Nadal, he has lost.

It takes plenty of optimism, coupled with a hefty dose of creativity, to think we’ll see a close match today.  Even arguing for the likelihood of a fourth set seems a bit much.

Such an argument, if it is to be at all reasonable, must hinge on two things.  First, that the underdogs are playing great tennis, better than their rankings and past results imply.  Second, that the favorites aren’t playing as well as they seem to be.

Underdogs poised for breakthrough?

Certainly, Wawrinka and Gasquet have faced tougher challenges than their opponents have.  Wawrinka has defeated two top-five players, making him 7-7 on the year against the top ten, an impressive mark for anyone other than, well, Djokovic or Nadal.  Gasquet has fought through two five-set battles, including a quarterfinal victory over David Ferrer, the sort of guy who doesn’t lose five-set battles to the likes of Gasquet.

In both cases, though, this argument can be taken too far.  Wawrinka has certainly been playing well, but neither of his last two victories are surprises anywhere near the extent a victory over Djokovic would be.  He had won two of his last five meetings with Andy Murray, and taken a set in two of Murray’s victories.  And even before his fourth-round match, he had a career winning record against Tomas Berdych.

If there is hope for Wawrinka, it comes in his record against Djokovic himself.  The last time they met, in Australia this year, the Swiss effectively fought to a draw, ultimately losing 12-10 in the deciding set.  Yet even that remarkable near-upset might overstate Stan’s case.  Even though it was Wawrinka who won a lopsided first set, Djokovic posted a dominance ratio (DR) of 1.10, meaning that he won 10% more return points than his opponent.  That’s almost always enough to win, and usually enough to avoid playing a sixth set.  Not to take anything away from Stan’s performance that day, but aside from a few lucky breaks, it was business as usual, with Novak playing superior tennis.

For Gasquet, it is even harder to make a case based on his own accomplishments.  He piled up an early lead against a listless Ferrer, then nearly blew it before playing a solid fifth set.  His level careened wildly during his fourth-round five-setter with Milos Raonic, a match which revealed character it shouldn’t have needed to draw upon.  This tournament is full of positives for Gasquet’s future, just not the very near future of his match with Rafa.

Indeed, to find any positive at all in the Nadal-Gasquet head-to-head, we need to go back more than five years, when the Frenchman won a 14-12 tiebreak on the way to a three-set loss.  Since then, everything has gone Rafa’s way.

Favorites overestimated?

If there is any chink in the armor of either Djokovic or Nadal, it is that they have yet to be tested in Flushing.  Neither has played an opponent ranked in the top 20, and Novak has played only one man ranked in the top 40.

So while both players have been dominant–Nadal overpowering almost beyond belief–it would be a mistake to conclude on the basis of these few matches that either player is in some sort of career-best form.  While most Grand Slam semifinalists have to play a third-round match, a fourth-round match, and a quarterfinal, it’s as if these two guys got a bonus second-rounder and two passes through the third round.

Unfortunately for Gasquet, it doesn’t matter what the evidence says about Rafa during this fortnight.  Take as many recent results as you want, and the conclusion is clear: Nadal is playing better than anyone.  The worst thing you can say about his hard court showing this year is that he’s lost a few sets.  He hasn’t lost a match on a hard court all year.  Sure, his dismantling of Tommy Robredo might overstate his capabilities, but not by much.  There’s simply no argument to be made that relies on Nadal’s weakness.

Djokovic, while ranked and seeded #1, hasn’t been quite so unbeatable.  He failed to reach the final of either summer Masters 1000 event, losing to Nadal in Montreal and John Isner in Cincinnati.  He hasn’t won a hard-court event since Dubai, six months ago.  In addition to the summer losses, he fell to Tommy Haas in the spring, and has lost hard-court sets to the likes of Denis Istomin, Fabio Fognini, and Sam Querrey.

That’s your dossier against the Serbian.  He’s not the undefeated Novak of 2011.  In short, he’s human–unlike Nadal.

The best-case scenario for Wawrinka is for a replay of the Melbourne match, with a couple more breaks going his way.  It’s far from likely–oddsmakers give Stan a roughly 25% chance of pulling off the upset, while my forecast is more pessimistic, figuring his chances at 14%.

Neither outcome seems particularly in doubt.  But whether today’s action lasts for six short sets or ten long ones, we can count on some entertaining tennis.  In current form, Gasquet and Wawrinka have two of the most beautiful (and devastating) backhands in the game.  And come to think of it, their semifinal opponents play some pretty good tennis, too.

Early Round Dominance and Women’s Semifinal Outcomes

Today’s women’s semifinals have at least one thing in common.  In both, one player has yet to drop a set at the US Open and has lost many fewer games than her opponent.

Does it matter?

The differences are particularly glaring in today’s second semifinal, between Serena Williams and Na Li.  Serena has not lost a set, and has dropped only 13 games.  Li has been pushed quite a bit further, losing 31 games in her first five matches.

Out of 714 Open-era Grand Slam semifinal matches, 30 have featured two players with such a wide gap.  To quantify it, we’ll note that Li has lost 2.38 times as many games as Serena has.  Of those 30 matches, the player who had displayed more dominance in the early rounds won 25.

Strangely, though, the connection has been much weaker in recent years.  Most of those 25 super-dominant semifinals were the usual suspects in WTA history: Margaret Court, Chris Evert, and Steffi Graf.  Only five of these lopsided pairings have taken place since 1994, and of those five, the less dominant player has won three.  The most recent example was Li’s semifinal in Australia.  She went into her match having lost 31 games, while her opponent, Maria Sharapova, had lost only 9.  Despite showing so much more weakness in the early rounds, Li won her semifinal 6-2 6-2.

In general, however, the more dominant the early rounds, the better chance a player has of reaching the final.  Of the 349 Slam semifinals in which one player had lost fewer games in her first five rounds, 228 (65.3%) advanced to the final.  The same percentage applies to the player who lost fewer sets en route to her semifinal.

Despite her low ranking and her buzzsaw of an opponent, this bodes well for Flavia Pennetta, right?

Well, not exactly.  As hardly needs mention, there are other factors involved here.  A great player might have a sloppy early-round match or suffer an unlucky draw.  That doesn’t mean she’s any less great, or less likely to show her top form in the semis.  Victoria Azarenka has certainly had a more challenging tournament so far than Pennetta has, but it would be a mistake to read too much into that.

For the most part, early-round dominance and superior WTA rankings go hand in hand.  Of 228 semifinal matches where I have ranking data, just over half (117) were won by the player who had dropped fewer games–who just happened to be the player with the better ranking.  No surprises here–if someone is going to play like Serena has so far, she’s probably #1.

The remaining 111 matches are where things get interesting.  In 75 of them, one player had the higher ranking (like Azarenka) and the other had been more dominant in the early rounds (like Pennetta).  The results favor the higher-ranked player, but not as much as you might expect: 30 of those 75 (40%) went in favor of the lower-ranked player.

Of course, most of those lower-ranked players aren’t quite the underdogs that Pennetta is.  As we saw yesterday, Flavia is one of the lowest ranked semifinalists in women’s Slam history.  Only two players outside of the top 32 have ever advanced to a final–Venus Williams at the 1997 US Open, and Serena at the 2007 Australian.  Whatever else you might say about the Italian, she’s not a Williams sister.

Using these two variables, though, it is Na Li who faces the tougher challenge today.  She’ll need to beat a higher-ranked player who has been untouchable through five rounds.  Keep the faith: That’s exactly what she did in Melbourne this year.