I’m going to be honest with you: I have my misgivings about advanced defensive metrics—especially those that are publicly available to schmoes like you and me. 1 It’s not that I think the methodology behind these stats is flawed or that the approach itself is a silly one—it’s just that all these metrics seem a bit too reliant on two somewhat flimsy inputs.
First, there is the simple problem of sample size: it is unlikely that a single player will accrue enough defensive opportunities on different sorts of batted balls in a given year to give us a realistic impression of what his actual skills are. It’s been said that you need three years of defensive data—I assume playing almost every day—to make up for this paucity. [Read more...]
- Craig just got back from the Sloan Analytics Conference, and I’m dying to talk to him about it. One item I’m hoping to discuss is the movement toward proprietary, team-housed analytics, especially in regard to defensive valuations in baseball. This is where it’s going, methinks. There was a decade or so where the schmoes were outsmarting the teams, but I’m pretty sure that’s over now. They’ve bought out the geniuses and their IP, and moved it behind closed doors. The “Moneyball Era” was exciting. But let’s face it: it’s over. [back]