While Juan Martin del Potro isn’t known for his return of serve, it isn’t a major hole in his game. This year, he has won 38.5% of return points, worse than most of the top 10, but better than Stanislas Wawrinka, Jo Wilfried Tsonga, and about 30 other members of the ATP top 50.
Where del Potro underwhelms is more specific. Despite effectively returning second serves, he’s far worse than average against first serves. In 2013, his 28.4% of first-serve-return points won ranked him 36th among the top 50, only 0.1% above Milos Raonic and far behind every other member of the top 10. Yet Delpo is in the top ten when it comes to second-serve-return points.
Even for a big server like del Potro, it’s difficult to reach the top five without an effective return game. While he breaks serve less often than any other World Tour Finals qualifier this year, he’s within a percentage point of Wawrinka, Tomas Berdych, and Roger Federer, so it’s clear that statistically, the Argentine is far from being a John Isner-style one-trick pony.
What sets him apart, then, is the enormous gap between first- and second-serve-return effectiveness. To illustrate the difference, I calculated the ratio of second-serve-return points to first-serve-return points for all eight men in London this week, plus Andy Murray. Delpo is third among all players with 40 or more tour-level matches this year, while the bottom five names on this list are all in the opposite third of ATP regulars.
Player v1W% v2W% v2/v1 Juan Martin Del Potro 28.4% 53.4% 1.88 Tomas Berdych 30.6% 54.6% 1.79 Richard Gasquet 30.5% 54.2% 1.78 Stanislas Wawrinka 30.7% 50.3% 1.64 David Ferrer 34.5% 56.4% 1.63 Andy Murray 33.7% 54.7% 1.62 Roger Federer 32.9% 51.6% 1.57 Novak Djokovic 35.5% 55.4% 1.56 Rafael Nadal 35.0% 54.6% 1.56
An aspect–or perhaps a cause–of del Potro’s first-serve-return woes is his knack for letting aces sail by him. In 2013, 10.5% of his opponents’ first serves were aces, more than any other member of the top 50. Controlling for opponent serve quality (he did play Isner twice this year), he “improves” to third-worst, ahead of Dmitry Tursunov and Feliciano Lopez. After this adjustment, we discover that Delpo allowed 22% more aces than an average player would have against the same set of opponents.
When aces are removed from the calculation, del Potro still stands out in comparison to other top players, but he is no longer quite so extreme. His ratio of second-serve-return points won to first-serve-return points won ignoring aces is 1.55, just a bit higher than Berdych’s 1.53, Richard Gasquet‘s 1.52, and David Ferrer‘s 1.51.
If Delpo gets a racquet on the ball, then, he’s not that much less effective against first offerings than his London competitors. But he doesn’t get his racquet on as many balls, and however we might manipulate the numbers for fun and profit, the Argentine doesn’t have the option to ignore aces.
So, how much does a poor first-serve return matter? As with Murray’s infamous second serve, it’s tough to say. In both cases, the weakness doesn’t keep its possessor from winning big matches against the game’s best, but it might be what is preventing him from ascending from the very top of the rankings.
Were del Potro to improve his first-serve return to the level of the next-worst London participant, Gasquet, it would mean a jump this year from 28.3% of first-serve-return points won to 30.5%. That would bump up his overall return points won to just short of 40%, and improve his break percentage from its current middle-of-the-pack 23.8% to a nearly-top-ten 26.0%, in the neighborhood of Berdych and Federer.
An improvement of that nature would make Delpo a much bigger factor at the very top of the men’s game. But like Murray’s second serve, it isn’t that easy. There’s more than one route to the top–del Potro’s game isn’t so unbalanced to keep him from beating the best players in the world, so perhaps he could more easily improve, say, his second serve than his first-serve return. It’s tough to tell from the sideline or, especially, the statsheet.
In the meantime, if you’re supporting del Potro tomorrow against Novak Djokovic, you might consider becoming one of those boorish fans that cheers every first-serve miss off of Novak’s racquet. Lots of Djokovic second serves might be Delpo’s best path to victory.
London forecast: With Berdych’s win today, all eight players remain in contention. A lot hinges on Friday’s match between Wawrinka and Ferrer, while we won’t gain much clarity on Group B until tomorrow.
Player 3-0 2-1 1-2 0-3 SF F W Nadal 70% 30% 0% 0% 98.4% 57.0% 34.1% Djokovic 42% 46% 11% 0% 88.3% 54.9% 30.9% Ferrer 0% 0% 54% 46% 14.8% 5.5% 2.0% Del Potro 22% 50% 28% 0% 71.6% 36.3% 16.4% Federer 0% 30% 51% 20% 29.9% 13.1% 5.9% Berdych 0% 30% 70% 0% 36.0% 12.4% 4.0% Wawrinka 0% 46% 54% 0% 50.9% 17.4% 5.6% Gasquet 0% 10% 44% 45% 10.1% 3.2% 1.0%
For the pre-tournament forecast, click here.
Berdych d. Ferrer: Click here for detailed serve, return, and shot-by-shot stats for today’s evening match.