SAN DIEGO, Calif. (KGTV) - Starting this season, all MLB stadiums will store baseballs in humidors as a way to equal the playing field, but that could lead to more home runs already humid ballparks like Petco Park in San Diego.
Alan Nathan is a retired professor of physics at the University of Illinois and specializes in the physics of baseball. He said humidors will regulate both the temperature and humidity at all 30 ballparks.
“Baseballs, wherever they’re stored, come into equilibrium with their environment, and if the environment is a humid environment, it absorbs water,” he said.
For cities that have dry air, this will increase the humidity of the environment for the balls, which Nathan said could decrease the distance they travel.
“When the ball absorbs water, the net effect is fly balls don’t go as far both because of the increased weight and because of the reduced bounciness,” he said.
But in places like San Diego that are more humid, the humidors could decrease the moisture for the balls, causing them to go farther.
“It depends on where your starting point is. if the baseballs had been stored in a very humid environment and you’re putting it in a humidor at a lower humidity, then you’re going to increase the bounciness of the ball, you’re going to increase the number of home runs.
He added that there are many other factors at play so this is not a guarantee, but the science supports more home runs at Petco Park this season.
“It’s likely that home run production will increase to some extent as a result of this,” he said.