Problems with PER
from the Wiki link:
PER largely measures offensive performance. Hollinger freely admits that two of the defensive statistics it incorporates -- blocks and steals -- can produce a distorted picture of a player's value and that PER is not a reliable measure of a player's defensive acumen. For example, Bruce Bowen, widely regarded as one of the best defenders in the NBA (at least through the 2006-07 season), has routinely posted single-digit PERs.
The same goes for Def Rating. It puts way too much emphasis on individual stats (blocks, steals) that can often come at the expense of overall team defense.
In addition, some have argued that PER gives undue weight to a player's contribution in limited minutes, or against a team's second unit, and it undervalues players who have enough diversity in their game to play starter's minutes.
Looking at you, Eric Bledsoe.
Lastly, PER rewards inefficient shooting. To quote Dave Berri, the author of The Wages of Wins:
"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 player 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."
Proof, in my opinion, that PER is a faulty stat. It's supposed to indicate a player's efficiency, but completely ignores his shooting efficiency.
This post was edited on 1/29 at 5:57 pm