MLB Umps Subject To Climate Change, According To Monmouth Study

WEST LONG BRANCH, NJ — According to a recent study published by Monmouth University’s Urban Coast Institute, Major League Baseball umpires are more likely to make bad pitch calls as the weather gets hotter outside and that baseball could be a victim of climate change.

In the study, Monmouth University associate economics professor Eric Fesselmeyer found that MLB umpires call pitches less accurately in uncomfortable temperatures.

When Fesselmeyer examined the accuracy of calls for 18,907 MLB games played between 2007 and 2017, he discovered a clear inverted U-pattern. Umpire accuracy was 86.3 percent when the temperature was below 50 degrees; 86.4 percent for temperatures between 50 and 60 degrees; 86.6 percent for temperatures between 70 and 80 degrees; peaking at 86.9 percent accuracy for temperatures between 80 and 90 degrees; falling to 86.5 percent for temperatures between 90 and 95 degrees; and 85.9 percent when the temperature was higher than 95 degrees.

The analysis shows that the pitch-calling error rate is about 1 percentage point worse when temperatures are above 95 degrees, while accuracy is highest in games played in 80-to-90-degree weather — making it possible that America’s pastime could be affected by climate change, as the warming temperatures and more frequent heat waves threaten to cause further decline in officiating.

“The drop in accuracy may seem small, but it is nontrivial for this high-revenue, high-stakes industry,” Fesselmeyer said in a news release about the study.

“Moreover, high temperatures cause an even greater decrease in accuracy on close call pitches along the edges of the strike zone.”