Last night, this tweet appeared on my timeline:
Thing I'm curious about tonight: Jedd Gyorko's defense. He's on par with Nolan Arenado in Defensive Runs Saved. Guessing positioned well
— Mark Simon (@msimonespn) July 17, 2017
Jedd Gyorko does indeed rank second in baseball in Defensive Runs Saved, at +13, behind only Nolan Arenado, and five whole runs ahead of Evan Longoria in third place. Last year, in a full season, only three third baseman (Arenado, Adrian Beltre, and Kyle Seager) contributed more positive value by DRS than 2017 Gyorko has racked up in half the playing time, and Beltre and Seager nipped him by just two runs a piece.
Either Gyorko, once a so-so second baseman in San Diego, has transformed himself into one of the best third baseman in the league in St. Louis, or something fishy is going on here. Let’s take a step back.
Today’s two most frequently cited fielding stats, DRS and UZR, both use batted-ball data and fielding zones to determine how well defenders are performing. Where offensive stats are somewhat concrete—a home run is a home run and a double is a double, for the most part—fielding stats are essentially estimates based on various assumptions, like how hard a ball was hit and where a fielder was initially standing. In an era where the exact data on how hard a ball was hit and where a fielder was initially standing exists, somewhere, thanks to Statcast, today’s advanced fielding metrics feel a tad archaic.