Later this week, my colleagues Alexander Franks and Andrew Miller, who are both PhD students at Harvard,1 will present a research paper at the MIT Sloan Sports Analytics Conference in Boston. In conjunction with professor Luke Bornn of Harvard’s Statistics Department and myself, Franks and Miller have been researching defensive analytics in the NBA for almost two years. You can [url=http://www.sloansportsconference.com/wp-content/uploads/2015/02/SSAC15-RP-Finalist-Counterpoints2.pdf]read the full paper here[/url], but here’s the elevator pitch: We are confident that we’ve developed methods that will enable analysts to more richly characterize defensive performance in the NBA.
Measuring defense is a challenging endeavor, and the behaviors of truly great defenders don’t fit nicely into the cells of spreadsheets. Highlight culture rewards individual offensive achievement, while the defenders in those clips are largely reduced to the same status as officials. If they do their jobs, people don’t even notice they’re there. (Unless we’re talking about Brandon Knight.) As a result, defensive reputations remain murky, and with a few exceptions — Zach Lowe’s wonderful article about the Raptors from two years ago, Ethan Sherwood Strauss’s look at the making of the Warriors defense — meaningful defensive analyses are rare.
In the summer of 2013, the NBA installed player-tracking systems in all 29 of its arenas. Every seemingly mundane action on the court would now be catalogued — from distance run to dribbles taken. But the massive new data set offered something else much juicier: the chance to finally analyze every second of defense played in every arena in the NBA.
It’s all in the little blue lines:
I don’t know enough about the NBA to know whether any of the examples confound eyeballs’ views, but here is Kawhi Leonard’s impressive defensive chart:
And these interior defenders: