Study: Blazers F LaMarcus Aldridge Among NBA's Best Interior Defenders

A research paper by Kirk Goldsberry and Eric Weiss, presented at the 2013 MIT Sloan Sports Analytics Conference, concludes that Portland Trail Blazers All-Star forward LaMarcus Aldridge is near the top of the list when it comes to field goal percentage allowed by interior defenders.

Aldridge ranks No. 5 on a chart of field goal percentage allowed when he is within five feet of the basket, trailing only Indiana Pacers center Roy Hibbert, Milwaukee Bucks center Larry Sanders, Dallas Mavericks forward Elton Brand and Oklahoma City Thunder forward Serge Ibaka. The data was culled from 75,000 field goal attempts taken during the 2011-12 and 2012-13 seasons using video tracking data.

Here's the PDF of the full study, which explains the paper's first goal.

The objective of the first case study was to examine the ability of interior defenders to "protect the basket." This case study considered shot attempts that occurred when there was an interior defender within 5 feet of the basket and was designed to measure two aspects of point prevention: the ability to prevent shots near the basket, and the ability to reduce the shooting efficiency of opponents near the basket. We evaluated shooting patterns using spatial splits. As a means to characterize the opponents' shooting tendencies, we calculated both the frequency and efficiency of shooting in each zone, but placed primary emphasis on close range shooting.

Click on the chart below to enlarge the results.

Here's a summary of the paper.

Basketball is a dualistic sport: all players compete on both offense and defense, and the core strategies of basketball revolve around scoring points on offense and preventing points on defense. However, conventional basketball statistics emphasize offensive performance much more than defensive performance. In the basketball analytics community, we do not have enough metrics and analytical frameworks to effectively characterize defensive play. However, although measuring defense has traditionally been difficult, new player tracking data are presenting new opportunities to understand defensive basketball.

This paper introduces new spatial and visual analytics capable of assessing and characterizing the nature of interior defense in the NBA. We present two case studies that each focus on a different component of defensive play. Our results suggest that the integration of spatial approaches and player tracking data not only promise to improve the status quo of defensive analytics, but also reveal some important challenges associated with evaluating defense.

Thanks to longtime friend of the site Douglas Hwang for the head's up.

-- Ben Golliver | benjamin.golliver@gmail.com | Twitter