from Amazon
Friday, August 05, 2011
Indirect v direct standardization
Great piece by Max.
So, let me reiterate the issue. When using indirect standardization (i.e., when using whatever existing fielding metric), you are entitled to say that both Player A (+20 plays) and Player B (+22) performed better than the average shortstop, but there is no way you can infer Player B performed two plays better than Player A.
...I believe fielding metrics should shift to the direct standardization method when data become more objective, detailed and unbiased. Until then the indirect standardization is an improvement over no standardization at all when players face different set of opportunities (but that’s when improper ranking might come out).
Indeed, back in the original UZR, MGL used direct and then switched to indirect after comments at the old Baseball Boards.