MEASURING DEFENSE IN THE NBA.

MEASURING DEFENSE IN THE NBA. Half of the game of basketball is played on defense, but little attention is paid to defensive accomplishments. Offense is measured by scoring, and all fans have a ranking in their heads of the scoring abilities of individual players. Not so for defense. On the day of the NBA all star game, which is entirely devoted to offense, the New York times published this article by Michael Lewis, who wrote MONEYBALL, about the discoveries that statistical analysts have made about baseball, and LIAR’S POKER, about modern finance. (I linked here to an article by Lewis about the current financial crisis). The article is about efforts by some NBA teams to measure defense. Shane Battier (portrayed defending against Kobe Bryant) is the focus of the article, as an example of a skilled defender whose efforts go unappreciated. Plus/minus statistics, although they have obvious flaws, are said to be a good starting point for measuring defense. (Plus/minus simply keeps track of your team’s net score during the period you are in the game). It is argued that it is very useful to have a hand in a shooter’s face in order to block his vision of the basket as he releases the ball. The statistician quoted in the article says that “the foul is the worst result of a defensive play” and that a team should “try dramatically not to foul.”