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# David Berri vs. John Hollinger

...and Malcolm Gladwell is siding with Berri.

Here's the nut of what Berri has to say:

Hollinger argues that each two point field goal made is worth about 1.65 points. A three point field goal made is worth 2.65 points. A missed field goal, though, costs a team 0.72 points.

Given these values, with a bit of math we can show that a player will break even on his two point field goal attempts if he hits on 30.4% of these shots. On three pointers the break-even point is 21.4%. If a player exceeds these thresholds, and virtually every NBA played does so with respect to two-point shots, the more he shoots the higher his value in PERs. So a player can be an inefficient scorer and simply inflate his value by taking a large number of shots.

But again, our model of wins suggests that inefficient shooting does not help a team win more games. Hence the conflict between PERs and Wins Produced. Hollinger has set his weights so that inefficient scorers still look pretty good. We argue that inefficient scoring reduces a team’s ability to win games, and therefore these players are not nearly as effective as people might believe.

As I recall from the last time I posted on Berri, some readers have a problem with Berri's conclusions, mostly because his system ends up highly valuing players like Ben Wallace and Dennis Rodman and Kevin Garnett and dismissing the value of players like Allen Iverson. But the more Berri's fleshes out in arguments, the more convinced I become.

If you're a skeptic, I urge you to start reading Berri's blog.

One more point: one of the fascinating things about this argument is how similar it is to the argument currently going on in medicine about "clinical" versus "acturial" decision-making. One study after another has demonstrated that in a number of critical diagnostic situations, the unaided judgment of most doctors is substantially inferior to a diagnosis made with the assistance of some kind of algorithm or decision-rule. Doctors don't like to admit this. But it happens to be true.

A lot of the huffing and puffing about Berri's ideas, it strikes me, is just basketball's version of the same defensiveness and close-mindedness.

First of all, I'm interested to see how Hollinger responds, and hope this is the kind of debate that leads to greater understanding of statistics, not macho posturing.

Secondly, there might be fifteen or more really tip-top NBA statistical theorists. Many work in silence, for NBA teams. Others just don't have Berri's gift for getting noticed. Somehow (I guess in large part because of the weight of Malcolm Gladwell's influence) The Wages of Wins approach seems to be having some success in emerging as the de facto standard by which other statistical systems must be judged. Before that call is made, I'd like to hear from the people on the front lines who work with these statistics in real NBA basketball settings every day. Without the weight of real world evidence of efficacy, this feels like a bit of a sideshow.

UPDATE: Hollinger responds.