{"id":1218,"date":"2013-08-19T13:48:32","date_gmt":"2013-08-19T17:48:32","guid":{"rendered":"http:\/\/heavytopspin.com\/?p=1218"},"modified":"2013-08-19T13:48:32","modified_gmt":"2013-08-19T17:48:32","slug":"toward-atomic-statistics","status":"publish","type":"post","link":"https:\/\/www.tennisabstract.com\/blog\/2013\/08\/19\/toward-atomic-statistics\/","title":{"rendered":"Toward Atomic Statistics"},"content":{"rendered":"

Italian translation at settesei.it<\/em><\/a><\/p>\n

The other day, Roger Federer mentioned in a press conference<\/a> that he’s “never been a big stat guy.” \u00a0And why would he be? \u00a0Television commentators and the reporters asking him post-match questions tend to harp on the same big-picture numbers, like break points converted and 2nd-serve points won.<\/p>\n

In other words, statistics that look better when you’re winning points. \u00a0How’s that for cutting edge insight: You get better results when you win more points. \u00a0If I were in Fed’s position, I wouldn’t be a “big stat guy” either.<\/p>\n

To the extent statistics have the potential to tell us about a particular player’s performance, we need to look at numbers that each player can control as much as possible. \u00a0Ace counts–though they are affected by returners to a limited extent<\/a>–are an example of one of the few commonly-tracked stats that directly reflect an aspect of a player’s performance. \u00a0You can have a big serving day with not too many aces and a mediocre serving day with more, but for the most part, lots of aces means you’re serving well. \u00a0Lots of double faults means you’re not.<\/p>\n

By contrast, think about points won on second serve, a favorite among the commentariat. \u00a0That statistic may weakly track second serve quality, but it also factors the returner’s second serve returns, as well as both player’s performance in rallies that begin close to an even keel. \u00a0It provides fodder for discussion, but it certainly doesn’t offer anything actionable for a player, or an explanation of exactly what either player did well in the match.<\/p>\n

Atomic statistics<\/strong><\/p>\n

Aces and double faults are a decent proxy for performance on serve. \u00a0(It would be nice to have unreturnables as well, since they have more in common with aces than they do with serves that are returned, however poorly.)<\/p>\n

But what about every other shot? \u00a0What about specific strategies?<\/p>\n

An obvious example of a base-level stat we should be counting is service return depth. \u00a0Yes, it’s affected by how well the opponent serves, but it refers to a single shot type, and one upon which the outcome of a match can hinge. \u00a0It can be clearly defined, and it’s actionable. \u00a0Fail to get a reasonable percentage of service returns past the service line, and a good player will beat you. \u00a0Put a majority of service returns in the backmost quarter of the court, and you’re neutralizing much of the server’s advantage.<\/p>\n

Here are more atomic statistics with the same type of potential:<\/p>\n