How MLB umpire grades really work, and what it means for the future of balls and strikes

AP Photo/Matt Slocum

ON THE MORNING after his called third strike that sent Philadelphia Phillies outfielder Kyle Schwarber into a fit of pique, Angel Hernandez, the umpire whose strike-zone judgment has inspired a million tweets, received an email. In it was a breakdown of his performance -- the same evaluation every umpire receives the day after he works the plate -- and on the pitch in question, the report was clear: Hernandez's call, in the eyes of Major League Baseball, was acceptable.

For anyone who saw last week's Sunday Night Baseball game on ESPN, or the clip of Schwarber slamming his bat and helmet before Hernandez ejected him, that assessment might be surprising. The on-screen circle that denotes whether a pitch at any point touched the strike zone was hollow, indicating it was a ball. How, then, could the pitch be an appropriate call in the eyes of Hernandez's bosses?

The answer is simple: The zone you see on TV is not the same as the one the league utilizes to grade home-plate umpire performance.

The criticism of umpires is a story as old as baseball, though never has it been as easily verifiable. First seen on ESPN broadcasts in 2001, visual representations of the strike zone are ubiquitous today -- on every major league broadcast, in the league's app and on its website -- and tracked by hobbyists and enthusiasts whose social media posts throw gasoline on every fan's fire that burns with apparent blown calls.