Kirk Goldsberry

The world of sports geekdom has always been about the numbers. Increasingly, though, it may be about the maps.

Many basketball statistics focus on discrete events — whether a player made a shot, or blocked one. But doesn’t it matter where those events happen?

Kirk Goldsberry, a visiting scholar on geography at Harvard, is one of the people at M.I.T.’s Sloan Sports Analytics Conference dabbling in sports after developing skills in another field. He has worked as a professor, and creating maps that give insight into public health issues.



He set out to answer who was the best shooter in the N.B.A., a quality that traditional metrics like shooting percentage do not fully address. (Tyson Chandler currently leads the league in field-goal percentage, for instance, largely because he specializes in the kind of jump shots that end with both of his hands touching the rim.

To do this, Goldsberry divided the area from just behind the 3-point line down to the rim into 1,284 “shooting cells,” and looked at how players shot during every N.B.A. game between 2006 and 2011. Not a single player took a shot from every spot on the floor. (Kobe Bryant came the closest, shooting from 1,071 places. ) Then, Goldsberry looked at which players averaged more than one point per attempt from the greatest percentage of the places they shot from.

By this analysis, Steve Nash and Ray Allen were the best shooters in the league.

This seems like a small revelation, but Goldsberry proposed other questions that could be answered through mapping: Where do the most steals occur? Where are the Pacers bad at defending against offensive rebounds? Where does Kevin Garnett tend to commit fouls?

There is likely to be a lot more thinking about the geography of the N.B.A. in the years to come. About a third of the league’s arenas have recently installed camera systems that capture and log the position of every player on the court 25 times a second. This has created huge databases of location data that will allow teams to determine how far a player runs in a game, or how many dribbles Kevin Durant generally takes before he shoots.

Current and former employees for N.B.A. teams said that the shift toward visual thinking was changing the skills that their analysts needed.

“You should see the files we get from these things. It’s just rows of X’s and O’s,” said Mike Zarren, assistant general manager of the Boston Celtics. “If you’re good at spatial analytics, I want to talk to you.”

Goldsberry’s analysis did not use data from the cameras, but another research paper presented at the conference mapped the places on the court where a missed shot was most likely to result in an offensive rebound. It found that the offense had a much better chance after missed layups and 3-pointers than on long 2-pointers.

Spatial analysis comes with another clear advantage, said Goldsberry: it is easy to understand. Several coaches and team executives at the conference described the necessity of keeping the statisticians away from the players, who should not be thinking about their relative shooting percentage on plays in which they take two dribbles rather than three.

A map, on the other hand, turns the mathematical rigor into a simple chart. Goldsberry showed off a map that plotted every spot on the floor where Bryant had shot from, color-coded by shooting percentage, so that it was clear where the defense would do best to send him.

“Virtually anybody can understand a well-designed chart,” Goldsberry said.