From Russell Carleton at Baseball Prospectus on November 9, 2017:
We need to talk some more about defense. Last week, I wrote about how uber-metrics, and particularly WAR(P), adjust for the position at which a player spends most of his time. We know that a shortstop is probably a better fielder than a first baseman, but neither ever really gets a chance to prove it. There are utility men, but as discussed last week (standing on the shoulders of Matt Winkelman), they’re a special case of baseball player. If nothing else, someone thought that them playing both second base and third base some of the time was a good idea, while the guy for whom they didn’t think that would work never got to do it.
The general way that WAR has adjusted for position is to look at the performance of players who have tried their hand at multiple positions within a season and to see how their defensive performance has rated at each place, compared to the average at the position. If “Smith” is plus three runs at shortstop, but plus seven runs when he plays second base, then shortstop must be four runs harder than second base, at least for him. We can take the average of that difference for all players who logged significant time at both spots and get some estimate.
Read the full article here: https://www.baseballprospectus.com/news/article/34881/baseball-therapy-short-changing-shortstops/
Originally published: November 9, 2017. Last Updated: November 9, 2017.