Strange phenomena in NBA player-performance modeling as the Wages of Wins Journal discusses Rashard Lewis:
Lewis is a comb0-forward, which means he has logged minutes at power forward and small forward in his career. WP48 is calculated by comparing a player relative to the average player at his position. Because power forwards tend to rebound at a higher rate than small forwards, power forwards tend to offer higher levels of productivity. So when Lewis is compared to players at the four spot, he tends not to look so good. Relative to small forwards, though, he can be very good.
To illustrate, consider last season. When Lewis played power forward his WP48 was only 0.096, which is close to average. At the three spot his WP48 was 0.209, which is above the “perfect” mark.
This is more than a little perverse. Good power forwards are hard to come by. That Rashard Lewis is capable of performing competently in that role is an asset he has as a player. But thanks to the WoW position-adjustment method, it registers as a problem for his game. If he was much, much worse at playing the 4, he'd never be asked to do it, and his WoW rating would look much better. But in the real world, he'd be a less valuable basketball player.
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Heads in the Sand
Well, this depends on how you view the role of player ratings. If you view the ratings as a measure of a player inherent basketball skills, yes, the flaw you discuss exists. However, if you view the ratings as a measure of a players actual production on the floor, they are perfectly acceptable. The issue, in that case, isn't with the player's skills, but rather with the coach not putting him in a position to maximize the his skills. Now, of course, a coach isn't paid to maximize any particular player's floow production, but rather the production of the entire team. So if a coach has a better team with Lewis playing a mediocre PF than with Lewis playing a very good SF, so be it; that all depends on the other players the coach has available to play at any particular time. (Indeed, the linked post mentions that this may be the case in Orlando with Lewis.) But, theoretically, each player should be put in a position to maximize his talent - that should get you the best team. If the actual players on the team don't allow for this - ie, if you don't have enough good PFs and Cs so that you are forced to play Lewis as a PF, where he is clearly mediocre - then the GM hasn't done his job.
Posted by Al | July 7, 2007 3:24 PM