TrueHoop: Kirk Goldsberry
March, 6, 2012
By Beckley Mason
Celtics coach Doc Rivers is credited with saying that “offense is spacing.” At the Sloan Sports Analytics Conference, Harvard researcher and Michigan State professor Kirk Goldsberry extended that logic to the whole game, explaining, “Basketball is a spatial sport.”
But when we compare shooters, it's important to note that field goal percentage is not a spatial statistic. It values shots from anywhere inside the 3-point line equally (as does the scoreboard). So while field goal percentage can tell us something about scoring, it doesn’t tell us much about shooting profiles. After all, who really thinks Tyson Chandler, the league leader by percentage, is really the game’s best shooter?
So who is?
Using spatial data mapping to track shooting, Goldsberry found that, in fact, Steve Nash is the game’s best shooter from the most places. To be more exact: Nash averages a point per shot (equal to 33 percent shooting on 3’s and 50 percent on 2’s) from more places than any other player.
As you can see in his CourtVision chart, Nash shoots just about every shot besides the baseline 2-pointer pretty well.
CourtVision by Kirk Goldsberry; Twitter: @KirkGoldsberry
That might not shock people who read this 2010 story from John Hollinger that came to the same conclusion (Insider).
But if the information contained in the charts isn’t new, the presentation is. Indeed, what’s really great about these charts is that they address the constant theme of the entire conference: Data is great, but players and coaches need information they can easily understand and reliably use.
The enormous amount of data that goes into these charts can be instantly understood at a glance. It’s not hard to imagine a time in the near future when every coaching staff in the NBA will carry an iPad-like tablet on the sideline to instantly relate this kind of shooting tendency data to players.
Example: Each defender could get a map of where his man is most likely to make a shot in the last two minutes and a map of the other team’s collective shooting tendencies. With this information, the defenders could better force opposing offensive players to the places on the court from where they are the worst shooters.
The cliché is that a picture is worth 1,000 words. In a 20-second timeout, when valuable talking time is scarce, how much could coaches say with a picture worth 10,000 data points?