Saturday, March 6, 2010
The value of a blocked shot
By Henry Abbott
On the NBA Playbook, Sebastian Pruiti describes a presentation by John Huizinga and Sandy Weil, who made a big impression at this conference last year with their paper which strongly questioned the existence of the hot hand.
This year they have examined blocked shots and have found that they are not all created equal.
Is blocking a layup more valuable than blocking a jump shot? Mr. Huizinga’s data says yes. In his presentation, he said that it all comes down to expected value. A jumper has an expected point value of 1.04 while a layup has an expected point value of 1.54. Looking at it this way, Brendan Haywood, who many people believe is a very good defender (me included) actually is a less valuable shot-blocker than Jermaine O’Neal.
Haywood gets 69% of his blocks on jumpers, meaning he only blocks 31% of the more valuable layups. On the other end of the spectrum, 91% of Jermaine O’Neal’s blocks were on layup attempts, while only 9% of his blocks were the less-valuable jump shots.
The paper also found that, with many different new factors taken into account, Tim Duncan's blocks are the most valuable in the NBA. The least valuable, they say, are Dwight Howard's.