WSJ: Defensive stats shifting back toward irrelevance

From Andrew Beaton and Michael Salfino at the Wall Street Journal on July 21, 2015, with mention of SABR members Vince Gennaro, Keith Woolner, and Mike Fitzgerald:

Baseball’s statisticians have long been looking for a way—any way—to figure out what a player is worth on defense. It was nothing less than the holy grail of baseball statistics.

For most of baseball’s existence, though, a fielder’s performance was evaluated by a group that is notoriously unreliable: human beings. Baseball defense was measured not by numbers but the eyes of scouts. To combat this inefficiency, the nerds went to work, coming up with computerized statistics that measured range and outs created, boiling the entirety of defensive performance down to a single number. Problem solved.

But now there’s another problem. A new trend—one that ironically also emerged from baseball’s quest to maximize defense—is rendering all that hard work moot: the defensive shift.

Many of the newfangled metrics that were built to judge a fielder’s range largely ignored where the player was actually standing when the ball was hit. So, the more teams shift defenders in between at-bats, the less the statistic makes any sense.

Read the full article here: http://www.wsj.com/articles/defensive-stats-shift-back-toward-irrelevance-1437518138



Originally published: July 21, 2015. Last Updated: July 21, 2015.