Umpires get ball/strike calls wrong 14% of the time, study finds…
Ever wonder just how accurate major league umpires are at calling balls and strikes? They obviously aren’t as accurate as us fans sitting in the seats — after all, we’re always right. But what percentage of ball/strike calls would you guess that umpires botch? 5%? 8%?
Would you believe 14%?
Researchers Brayden King and Jerry Kim analyzed more than 700,000 pitches thrown during the 2008 and 2009 seasons and found that about 14% of non-swinging pitches were called erroneously. King and Kim made their study by analyzing pitch-location data compiled by the high-speed cameras used by Major League Baseball to monitor umpires’ accuracy.
Here are some of the more notable ways they say umps make mistakes:
- Umpires tended to favor the home team by expanding the strike zone, calling a strike when the pitch was actually a ball 13.3% of the time for home-team pitchers.
- Umpires were 13% more likely to call a strike a ball in the bottom of the ninth inning of a tie game than in the top of the first inning, on the first pitch.
- When the count was 3-and-0, umpires mistakenly called a strike 18.6% of the time.
- Umpires were 10% less likely to expand the strike zone for African American pitchers than for Caucasian pitchers.