Category: Match charting

The Questionable Wisdom of the Drop Shot

Italian translation at settesei.it

More than any other shot in tennis, the drop shot can make the player who hits it look either brilliant or idiotic.  The line separating the two is rarely so fine.

When we combine the brilliance and the idiocy, how does the drop shot measure up?  How much does a player gain or lose with frequent use of the dropper?

In the final match of last week’s Challenger Tour Finals between Alejandro Gonzalez and Filippo Volandri, Volandri hit a whopping 23 drop shots–almost one per game (click the “Shot Types” links).  Volandri is a seasoned pro with an excellent sense of clay court tactics, so he avoided the clunkiest drop shot misses–only three of the 23 were errors.  Yet despite facing an opponent who prefers to camp out well behind the baseline, the Italian won only 11 of the 23 points.  Almost half the time the drop shot landed in the court, Gonzalez chased it down, got a return in play, and went on to win the point.

Volandri’s performance in the final wasn’t an anomaly.  In the semifinal against Teymuraz Gabashvili, he attempted 17 drop shots and won only nine of those points.  The other aggressive drop-shotter at the CTF, Oleksandr Nedovyesov, hit 19 drop shots against Gabashvili in a round-robin match.  Even though eight of those 19 drop shots were winners, Nedovyesov lost ten of the ensuing points.

With my shot-by-shot analyses of five matches from last week’s event in Sao Paulo, we can take a somewhat broader look at drop shot tactics and their results.  While this subset may not be representative of all clay-court tennis (for one thing, the altitude makes it a bit easier to chase down a dropper), the aggregate numbers raise some questions about the wisdom of the drop-shot tactic.

As a whole, the six players who took part in these five matches hit 95 drop shots.  16 (16.8%) of them were unforced errors, compared to an overall rate of about 1 unforced error per 10 rallying shots.  29 (30.5%) were outright winners, while another five induced forced errors, immediately ending the point.  That leaves 45 points (47.4%) in which the opponent got the ball back in play.  Of those, the dropshotter won only 19 (42.2%).

Taken together, the results aren’t bad.  The player who hit the drop shot won 53 (55.8%) of the points, and 67.1% of the points when the drop shot landed in play.

There is a noticeable difference, however, in the success rates of the frequent dropshotters (Voladri and Nedovyesov) compared to those of the other four players, who averaged fewer than four drop shots per match.  While the players of what I’ll call the “infrequent group”–Gabashvili, Gonzalez, Guilherme Clezar, and Jesse Huta Galung–may not be as practiced in the art, it is likely that they chose their moments much more carefully, hitting drop shots when the tactic was obvious.

The infrequent group hit 22 drop shots, missing only two.  Not only did nine go for winners, but the overall results were positive as well, as they won 14 (63.6%) of those points.

Remove the infrequent group from the overall numbers, and the aggressive dropshotters won a mere 53.4% of points in which they used the tactic.

53.4% isn’t awful–if you win 53.4% of the points in a match, you almost always win.  However, the type of point in which the drop shot makes sense isn’t an average point.  Usually the dropshotter has better court position than his opponent, who may be off-balance or far behind the baseline.  This isn’t always the case, especially when the dropshotter is simply trying to end the point, or when his brain stops working.  But in the majority of cases, the dropshotter has such an advantage in court position, it seems likely that a more common tactic–such as an aggressive groundstroke, perhaps followed by a net approach–would do better.

Another consideration goes beyond the outcome of a specific point.  A player who fails to run down a drop shot will probably remember that lost point for a game or two and play a little closer to the baseline, maybe making himself less comfortable in the process.  It’s possible that the long-term effect gives an advantage to the player who regularly uses the tactic.

But somewhere between Gonzalez’s four drop shots on Sunday and Volandri’s 23, the marginal advantage of each additional dropper must wear off.  I find it hard to imagine that one drop shot per game has any more of a long-term strategic effect than one drop shot per three games.  If that’s true, Volandri hit 13 or 14 more drop shots than required.  Thus, in about 8% of Sunday’s 162 points, he took an advantageous court position and wasted it on an even-odds shot.

More evidence will surely give us a fuller picture of drop-shot tactics on clay courts.  We may be able to determine whether there is a post-dropper “hangover effect” and if so, how many drop shots are required to reap the benefits.  Until then, it’s worth considering whether drop shots are worth the risk, especially when there may be such a high-percentage alternative.

Novak Djokovic and Neutralizing the Second Serve

Italian translation at settesei.it

When Novak Djokovic stands on the other side of the court, you’d better make some first serves.

Djokovic is one of only two players this year to win more than 55% of second-serve-return points (David Ferrer is the other).  When you consider that he also wins more than 35% of first-serve-return points, it’s less clear that the server has much of an advantage.  In fact, when Novak is performing at that level, if his opponent goes through a bad patch and only makes a quarter of his first serves, Djokovic has a better than 50% chance of breaking serve.

Commentators often refer to Djokovic’s return as a weapon, and they’re not joking.  Only six players (including Novak himself and, invariably, John Isner) won as many second-serve points as Novak won second-serve-return points.

What’s most remarkable about his return game is how quickly he neutralizes the second serve, often using tactics that, in the hands of lesser mortals, would be more appropriate for service points.  Unlike other returners, he is somewhat more likely to win a short return point than a long one.  While other players need a few shots to negate the advantage conferred by serving, Djokovic is most effective early in service points.

This graph shows the percentage of second-serve-return points won by Djokovic, by rally length, in four matches I’ve charted (US Open vs Stanislas Wawrinka and Rafael Nadal; Tour Finals vs Wawrinka and Juan Martin del Potro), compared to the the same percentage for other top-ten players (excluding Rafael Nadal) in 19 other matches I’ve charted from the US Open and Tour Finals this year:

novak1

When the return lands in play, Djokovic wins almost 53% of return points, while the pack manages less than 44%.  (All of these matches are between top-ten opponents, so the averages are much lower than season numbers, which are affected by matches against lesser opponents.)  The difference stays about the same when we take out 2- and 3-shot rallies.

When we limit our view to points that reach six shots, Novak still has a substantial edge, roughly 48% to 42%.  But in points longer than seven shots, there’s virtually no difference.

Djokovic’s return is so good that if his opponent misses his first serve, the point has turned into a Novak service point.  Opponents are forced to fight their way into their own service points!

This was particularly true in the Djokovic-Nadal US Open final.  (Follow the link, then click the ‘Serve Influence’ tab for a shot-by-shot winning percentage breakdown.)  Nadal won barely half of his second-serve points when Djokovic got his return in play, but once the rally reached five shots (or six, or seven, and so on), Nadal had the edge, winning 60% of points.  From the five-shot mark, Rafa’s advantage only increased.

Of course, Nadal won that match.  It’s not quite so useful to convert return points into service against an opponent whose own return of serve is so effective.  To win today, Novak needs to do more than just attack Rafa’s second serve.  He must either do so even more effectively than he did in New York, or put himself in a better position to win longer return points after the effect of his return has worn off.

US Open Point-by-Point Stats Recap

As regular readers know, I’m working on a system to track every shot in a tennis match and then generate meaningful data based on the results.  Once I hammer out a few final bugs, I’ll introduce that system publicly.  Then, with my interactive Excel doc–and at least a little bit of practice–you can chart matches as well.

In the meantime, I’ve added another set of tables to each one of the point-by-point recaps.  My system allows (but does not require) the tracking of each shot’s direction, which seems particularly valuable in the case of a tactical baseline matchup like Monday’s final.  Follow the link to the men’s final stats, and then click either of the “shot direction” links.  I’ve broken down each player’s shots into crosscourt, down the middle, down the line, inside-out, and inside-in, then broken down each specific shot type (e.g. “forehand inside-out”) and shown the results of that shot.

At this point, the numbers are little more than a basis for conversation and speculation.  Except for Serena Williams and Victoria Azarenka, I don’t have stats on more than two matches for any individual player.  In time, however, I expect to amass a fair amount of raw data on the top-ranked men and women, and from there, we might really be able to learn something.

In the meantime, here is a list of all the point-by-point stat summaries available from the US Open.

Men:

Women:

Bonus:

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.

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.

Wawrinka d. Murray: Recap and Detailed Stats

The narrative felt familiar.  A flashy player from the fringes of the top ten takes on an established top-five guy, a great defender who would be sure to outlast his opponent in the end.

Yesterday, it was Gasquet and Ferrer.  Today, Stanislas Wawrinka and Andy Murray.  Even after Wawrinka took the first set, the same talking points reappeared: Surely Wawrinka would press, or tire, or Murray would wake up and play better tennis.  Fortunately for Stan, he didn’t have to fight off as spirited a comeback as Gasquet did; he simply kept employing the same successful strategies while Murray, passive and error-ridden, let him run away with the match.

While Murray’s impotence will be the story of this match–he hit only 15 winners in the entire match, and that includes six aces–much must be said about Wawrinka’s game plan.

The Swiss is known for his backhand, but unlike Gasquet, he doesn’t unduly favor it.  Roughly 40% of his groundstrokes are backhands (including slices), meaning he is willing to move around it and attack with the forehand.  The Wawrinka forehand is a weapon that is known to break down, but when it’s working, it can be just as deadly as the backhand.  It didn’t falter today: Stan earned 27 winners and induced five additional forced errors with shots from that side.

But the forehand was only a complementary part of the attack.  What continued to surprise throughout the match was Wawrinka’s willingness–sometimes over-eagerness–to come to net.  His transition game is a little awkward, and many of his errors came from failed approach shots, but by continually putting more pressure on Murray, he closed out points when Andy would’ve been content to let them go on for ten more shots.

Another underrated part of Wawrinka’s game is the serve.  While Stan will never post eye-popping ace numbers, it’s an effective shot that sets up the rest of his game well.  Today, he only tallied four aces and one unreturnable, but of 76 total serve points, Wawrinka won 29 of them with or before his second shot.  That isn’t as foolproof as an Isner-like ace tally, but the end result is the same.

And sure enough, it prevented Murray from even sniffing opportunity.  Murray didn’t earn a single break point in the match, the first time he has failed to generate one since his loss to Roger Federer in the 2010 World Tour Finals.

Wawrinka, on the other hand, pushed Murray to 30-30 in almost every one of his service games, and after suffering through a marathon game at the end of the first set, in which he needed seven opportunities to seal the break and the set, he didn’t waste nearly so much time again.  The Swiss converted three of five break point opportunities after that first set.

It was a bad day for Murray, that’s for sure.  It represented a step back to before his days as an Olympic and Grand Slam champion, and it may be a tough one to bounce back from.  Wawrinka, on the other hand, forces us to consider him as one of the “next four,” perhaps the Swiss #1 sooner rather than later.  He won’t always beat Murray with today’s game plan, but he’ll do more damage against higher-ranked players.

In Saturday’s semifinal against Djokovic? That’ll be a big ask, even playing the way he did today.  Novak has reeled off eleven victories in a row in their head-to-head, though their last match was the marathon fourth-rounder in Australia, when Stan pushed him to 12-10 in the fifth set.  The semi won’t have the star power it would’ve with Murray, but we can expect some great tennis.

Here are my detailed serve, return, and shot-type stats for today’s match.

Gasquet d. Ferrer: Recap and Detailed Stats

The knock on Richard Gasquet has long been his inability to play the big matches, to overcome higher-ranked opponents, even when he has the weapons to defeat them.  David Ferrer is the sort of guy who eats such players for lunch.  One might figure the Frenchman would win a set, but not that he would find his way into the semifinals of a Grand Slam.

For two sets today, Gasquet played as well as I’ve ever seen him play. He combined patience with his devastating down-the-line backhand, waiting eight, ten, or more shots before the opportunities arose to unleash the monster.

What’s remarkable is that most conventional stats don’t bear this out. He barely got half of his first serves in. He hit a mere seven winners in the first set, against a dozen unforced errors. But he coaxed plenty of mistakes out of an opponent who doesn’t often make many.

Gasquet was able to race to his two-set lead in large part because Ferrer wasn’t playing his best tennis. The tactics looked familiar, but Ferru wasn’t quite as aggressive as usual, letting Gasquet earn those opportunities to strike. Ferrer hit only three winners in the entire second set.

The next two sets fulfilled everyone’s expectations. Despite his five-set triumph over Milos Raonic, Gasquet’s history suggests he would mentally fade, and perhaps physically give out long before Ferrer would. As the Spaniard piled on the breaks, those forecasts appeared to come true.

Ferrer’s success against Gasquet’s serve tells the story. While failing to win more than 30% of return points in the first two sets, suddenly he won half of Gasquet’s service points. With Gasquet playing more listlessly, settling in further back in the court, a couple of breaks were plenty.

It would have been easy for the Frenchman to go away in the fifth set; he’s done it before. Ferrer’s reputation precedes him, and certainly, he showed no signs of physically weakening as the match went into its fifth hour.

But Gasquet dug out of a 15-30 hole to win his opening service game; he fought past two deuces and a break point to win his second. With both players settling in for a grind, the turning point came on Gasquet’s only break point of the deciding set, when Ferrer double-faulted to give his opponent a 5-2 advantage.

Thanks to a couple of errors from Ferrer in the final game and a big serve on match point, the Spaniard never had another opportunity. Gasquet moves to the semifinals and a probable date with Rafael Nadal.

It was only Gasquet’s second win against Ferrer in nine meetings, and only his seventh career win in a five-setter. His only previous five-set win against a higher-ranked opponent was in his only prior Grand Slam quarterfinal, in 2007 at Wimbledon against Andy Roddick.

And now, after winning his second Grand Slam fourth-round match in 17 tries, he moves to a perfect 2-0 in quarterfinals.

Here are my complete serve, return, and rally length stats for the match.

Murray d. Istomin: Recap and Detailed Stats

Tonight Andy Murray defeated Denis Istomin in four sets for a place in the quarterfinals against Stanislas Wawrinka. I logged every point, and have lots of stats for you to check out.

In particular, check out the new “key points” and “rally length” tables.

Murray started out sluggishly and never appeared to play at 100%. But what he brought was good enough, especially in the second set, when Istomin went down an early break and immediately started looking to the third set.

Istomin has a big game, with the ability to dictate play from the baseline. Murray spent a lot of time in classic Andy defense mode, and often it worked, as perhaps Istomin’s greatest weakness is his predilection for low-percentage shots. His 58 unforced errors (not counting double faults) don’t even convey the whole story, as so many of those should have been simple rallying shots.  It may not be easy to construct a point against a defender like Murray, but Istomin’s tactics didn’t do him much credit.

While Murray came through tonight, it marks another sign of weakness for defending champ. Playing like he did tonight won’t be enough to beat Wawrinka, let alone Novak Djokovic in the semifinals. His serve never really got going, and once he learned he could trust Istomin to lose points without too much help, he waited out his opponent. It worked, but it took over three hours. Andy in champion mode should have won this one in less than two.

Here are the complete chart-based stats.