The third post of a series used explaining the statistics that have and will be used on this site, noting their strengths, shortcomings, and how they apply to the Knicks. (Intro, Adjusted Plus/Minus)

If you asked someone to name a new, advanced basketball statistic, chances are they would mention Player Efficiency (PER). It has flaws, but by virtue of being the basketball statistic of choice on ESPN, it is arguably the most referenced statistic. Whether it is used correctly or not is another question.

Contrary to adjusted +/-, PER generally reinforces the public perception of players. Of the top 20 players by PER last season, 19 had made at least one All-Star Game during their career. One type of adjusted +/-, on the other hand, placed Chris Andersen, Anderson Varejao, Dorell Wright, and Ben Wallace as top twenty players last season.

The reason for this is fairly clear.

What is it, exactly? PER relies on box-score statistics, and simply subtracts the bad (turnovers, missed shots, etc.) from the good, with the average set at 15. Points, rebounds (rebound rate, more specifically), assists, steals, blocks, turnovers, and fouls are all found in a normal box-score, and thus all are incorporated into PER’s formula. PER usually does not contradict public opinion because it is solely based on the statistics which are already ingrained in fans’ minds. The surprise PER ratings are generally derived from the incorporation of turnovers and shooting efficiency, as well as its use of per-minute statistics.

Top 10 in ’09-10: LeBron James, Dwyane Wade, Kevin Durant, Chris Bosh, Tim Duncan, Dwight Howard, Chris Paul, Greg Oden, Dirk Nowitzki, Pau Gasol

Pros:
- It is generally a good indicator of scoring efficiency, but its inclusion of other statistics (rebounds, steals, etc.) can muddy these figures.
- Good season-to-season consistency.

Cons:
- Disregards defense. Anyone who has watched a basketball game realizes that defense extends beyond steals and blocks, which are often fortuitous occurrences. Defensive maestro Bruce Bowen never had his PER exceed 10, while Shane Battier’s PER was above-average just once.
- There have been claims that PER rewards inefficient shooters that shoot more.

On the Knicks: David Lee posted the 14th best PER rating last season (22.28), trailing Amar’e Stoudemire (11th) by just 0.41. New Knick Anthony Randolph posted the 40th best rating in the league (18.71), which was enough to put him past Derrick Rose, Tyreke Evans, and Paul Pierce, to name a few. Meanwhile, Wilson Chandler recorded a below-average score of 13.76, and Gallinari was only slightly better.

How should it be used? If PER has to be used, it should be used as just one measure of scoring efficiency. The problem is that ESPN attempts to pass it off as an all-inclusive rating of a player’s true worth, and this “contaminates” the ratings. A player could shoot at 50%, but if he does not do much on the boards or elsewhere, for example, his PER suffers.

Links: What is PER?, PER Numbers (Insider req’d), Calculating PER

Photo: Juan Ocampo/NBAE/Getty Images