Lindbergh: What we can learn about widening the strike zone from Brad Ausmus and Dennis Eckersley

From SABR member Ben Lindbergh at Grantland on February 12, 2015:

The week before my first day, a group lunch at Sheppard’s Place, the cafeteria attached to the press box, had led to an exciting discovery. Half the front office sat together and spitballed: director of pro scouting Billy Eppler, director of quantitative analysis Michael Fishman, pro scouting manager Will Kuntz, baseball operations assistant Steve Martone, and Alex Rubin, an intern who had started the previous season. The night before, backup catcher Jose Molina had guided Phil Hughes through six scoreless innings in Detroit, and the conversation turned to Molina’s defensive edge over regular starter Jorge Posada, who often frustrated observers by catching pitches so awkwardly that he cost his pitchers strikes. Could it be, someone wondered, that the gulf between Molina’s and Posada’s gloves could make up the difference on offense between one of baseball’s worst-hitting catchers and one of its best? The consensus was that it wasn’t possible, and the group tabled the idea.

But Rubin — who would eventually be hired as a full-time analyst before leaving to work for the MTA as a self-described “transportation sabermetrician” — had gotten curious. He was on Team Posada, and he wanted to be proven right. After lunch, while he was supposed to be doing data cleanup, he started researching the size of the strike zone with Molina and Posada behind the plate.

The pitch-tracking data he needed to settle the dispute was then only in its second full season, and almost no public research on the subject existed, save for one post whose author, Dan Turkenkopf, had been so skeptical about his own results that the Internet had largely discounted them. Rubin found a more sophisticated, probabilistic way to model the strike zone than Turkenkopf had, and his results seemed robust. “I was just trying to settle a lunchtime argument with some coworkers,” Rubin says. “And then I stumbled into a discovery that proved me more wrong than I ever could have believed.” No matter what queries Rubin ran, no matter what adjustments he made, he kept coming up with the same answer: The difference between the two catchers was dramatic. Team Molina always won. And the epiphany had arisen in storybook style out of a conversation between statisticians and scouts, a case where the eye test had inspired a statistical test that reinforced what the scouts saw.

Read the full article here: http://grantland.com/features/brad-asumus-pitch-framing-dennis-eckersley/



Originally published: February 12, 2015. Last Updated: February 12, 2015.