Do Umpires Discriminate In Favor of Veterans?

From SABR member Phil Birnbaum at Sabermetric Research on August 1:

At the SABR convention last month, some evidence was unveiled that suggests that umpires give more favorable ball/strike calls to veterans.

Pat Kilgo gave a presentation, “Do Umpires Give Favorable Treatment to Some Players?” He and his colleagues — Hillary Superak, Lisa Elon, Mark Katz, Paul Weiss, Jeff Switchenko, Brian Schmotzer, and Lance Waller — looked at called pitches from 2009-10. They compared the call to the PitchF/X data, and, from that, decided if it was a correct call, a “false strike,” or a “false ball”.

They then created a matrix classifying both the batter and pitcher by years of experience. There were 16 classifications for each, from “0-1 year experience” to “more than 15 years experience”. So the matrix had 256 cells. Each cell contained the percentage of “false strikes” for that situation.

As it turned out, there were many, many more false strikes when the pitcher had a lot of experience but the batter did not. And there were many *fewer* false strikes when the situation was reversed, with an experienced batter and rookie-ish pitcher.

Read the full article here:

Originally published: August 5, 2011. Last Updated: August 5, 2011.