Italian translation at settesei.it
Over the weekend, Tom Perrotta made the claim that grand slam champions such as Roger Federer and Serena Williams got that way, in part, by keeping early matches short. In his words: “They’re great at not being exhausted.”
This is intuitively appealing, especially after a third round in which Federer and Novak Djokovic barely broke a sweat, while Andy Murray, David Ferrer, and Tomas Berdych each dropped a set. (Even Juan Martin Del Potro was forced to a tiebreak by Leonardo Mayer.)
Before we get carried away, let’s find out what the numbers tell us. As we’ll see, slam champions usually are the men who spent fewer minutes on court getting to the final. It’s less clear, though, whether there is a causal link: After all, a better player should have an easier time of it in the early going.
The ATP has complete match-length numbers for our purposes going back to 2001. That gives us enough data to look at the last 47 slams.
In the last 47 grand slam finals, the favorite (defined simply as the guy with the better ATP ranking) won 33 times. In 6 of the 14 slam finals in which the underdog won, the underdog had spent less time on court in his previous six matches than the favorite did in his. Pretty good, huh?
One problem: Six other times, the favorite won the final despite having spent more time on court. So if you have to pick between the favorite and the better-rested player, there’s nothing in this sample to differentiate your choices.
A more positive takeaway occurs when the favorite has spent less time on court. There have been 35 such finals since 2001, and the better-rested favorite has gone 27-8. Most of the time, the favorite has reached the final expending less effort than his challenger did, and perhaps we can view that as a confirmation of his status as favorite.
(If you prefer games played to minutes on court, perhaps in deference to the Nadal and Djokovic speed of play, rest assured the numbers come out almost identical. There are a few cases where players spent less time on court but played more games–or vice versa–but if the analysis above replaced minutes with games, the results would be the same.)
All else equal, we’d bet on the finalist who has spent less time on court. But that doesn’t necessary imply that the better-rested player is more likely to win the final because he hasn’t spent as much time on court. That seems particularly true at slams, where players almost always get a day of rest between matches, and where top contenders almost never play doubles.
More likely is that one player spent less time on court because he is the favorite. Surely no one was surprised when Federer breezed past Verdasco, and few were surprised that Murray needed more time to put away Feliciano Lopez. Time on court is a clue that one man is playing better tennis, regardless of whether the extra rest aids him in later matches.
We can probably all agree on a safer claim: All else equal, the world’s best would certainly prefer to spend less time on court, even if it doesn’t boost his odds of winning the final. It might be gratifying to fight off an early challenge, but surely it’s more enjoyable to remind the rest of the field why you’re the favorite.