A fantasy lesson in drop rates 

August, 17, 2010

Today's winners in Stats & Analytics:

Calvin Johnson, Mohamed Massaquoi, Roddy White

Today's losers:

Isiah Thomas, the Seattle Mariners, Roy Williams

Football Outsiders is out with a fascinating new metric called plus-minus, which breaks down wide receivers as only Outsiders can. But I think adding a step would make it even more useful for spotting value among fantasy receivers. It's all about the dropsies.

Plus-minus looks at each of a receiver's targets and calculates how many catches he should have had, given the down, distance and direction of the attempts thrown his way. (Bill Barnwell describes the nuts and bolts of the process in an excellent essay here. This reveals players whose catch rates are improbably high and therefore overvalued (like Robert Meachem), and aberrantly low and therefore undervalued (like Roddy White).

That's very cool, and for the most part it makes perfect sense. But it made me wonder about just how to apportion the blame for a low catch rate. Of course, a receiver might just have an off year, in which case we would expect him to improve just by regression to the mean.