Rising Temperatures Could be a Game-Changer for Major League Baseball

Baseball Climate Change Extreme Heat

According to a forthcoming study from Monmouth University, climate change could negatively impact America's favorite pastime. Professor of Economics Eric Fesselmeyer analyzed 18,907 Major League Baseball (MLB) games and found that when temperatures were above 95 degrees Fahrenheit, umpires were more likely to make call pitches incorrectly. Fesselmeyer is still investigating how heat impacts pitch-calling, but one thing is for sure: baseball fans everywhere may see the game change for good.

Why This Matters

It's easy to think of climate change as big events like wildfires, hurricanes, and drought. But climate change is sneaking into our daily lives in small ways, for example:

  • The alcohol content in wine is increasing due to higher growing temperatures, and flavor is suffering due to wildfire smoke tainting grapes.
  • Production of the most common coffee species is expected to plummet by 2050 due to rising temperatures.

Baseball is the latest victim of rapidly rising temperatures. In 2020, MLB pulled in $3.66 billion and employed 24,000+ people. Any threat to the integrity of baseball impacts not only fan enjoyment but also the billion-dollar baseball industry and the livelihoods of thousands. Fesselmeyer says his findings have implications beyond baseball and that worker performance could be negatively affected by heat in other sectors, including agriculture, construction, and manufacturing.

Changing The Game

Fesselmeyer's examination found that pitch-calling accuracy suffered at low and high temperatures but suffered the most above 95 degrees.

  • Pitch-calling was 86.3% accurate below 50 degrees, 86.4% between 50 and 60 degrees, and 86.6% between 70 and 80 degrees.
  • Temperatures between 80 and 90 degrees saw the most accurate calls, with 86.9% accuracy. Accuracy then fell to 86.5% between 90 and 95 degrees and 85.9% above 95.

Although these changes seem small, Fesselmeyer says they're significant enough to change the game. "The drop in accuracy may seem small, but it is nontrivial for this high-revenue, high-stakes industry," he said. "Moreover, high temperatures cause an even greater decrease in accuracy on close call pitches along the edges of the strike zone."

Fessselmeyer investigated other factors that could cause these disparities. He hypothesized that umpires might be calling pitches differently to shorten games in uncomfortable heat, but he ruled out that possibility upon further analysis. He also found that factors like experience level, workloads and age of umpires, game attendance and duration, and weather conditions didn’t impact the way umpires called pitches in hot temperatures.

Automated pitch-calling is already in the works, and baseball experts say it could bring average accuracy up significantly. "MLB is indeed considering robo-umps, which would have the added benefit of eliminating the effect of high temperatures on pitch calling," said Fesselmeyer. "But it is not clear whether the technology will be adopted because baseball purists prefer to preserve the human element in the game."

NASA: Earth Observatory image of temperature anomalies on June 27th, 2021 compared to 2014-2020 average for the same day during the 2021 western North America heatwave.