Considering that this past summer was the hottest on record, and that scientists predict temperatures will continue to rise about 3.6 degrees Fahrenheit over the next half-century, it stands to reason that more changes are in store for the planet—and the game of baseball.
For example, if pitchers’ moods change in the heat, what about the mood of the ball? How does a baseball react—how does it travel—in hot weather? Michael Mann, a climate scientist and director of Penn State’s Earth System Science Center, writes via email that the ball reacts differently in the heat, and the reason is the density of the air. Hot, humid days are less dense than cool, dry ones.
“If we change the density of the atmosphere near the surface of the earth, that will influence the behavior of objects that are thrown or hit through the atmosphere,” he writes. “That of course includes baseballs. Lower density means less air resistance, which would mean balls would get hit farther.”
In other words, all conditions being equal, a long fly ball that reaches the warning track in April might be a home run on a scorching day in July.
Which brings us to Arlington, a neighbor of Dallas, and home of the Texas Rangers. There, temperatures routinely reach the 90s throughout the summer. This past August alone, the thermometer topped 100 on 12 different days.
Former Rangers head trainer Danny Wheat spent two decades conditioning the Rangers to play in Arlington Stadium, then Globe Life Park, neither of which had a roof. “It seemed like, from June to September, we started every game at seven o’clock, and it was 97, or 100-plus,” he says. “And the sun didn’t go down until nine or nine-thirty. You’re into the sixth inning by then. Even at the end of the game, it would be 90 degrees.”
To combat dehydration, Wheat pumped his players with electrolytes in the form of Gatorade, Powerade, and Pedialyte. Nonetheless, by August and September, his players were noticeably weaker than they were in April and May. “We always had what seemed to be a lot more soft-tissue leg injuries than some of the other clubs. Hamstrings, calf injuries, from guys running the bases,” he says. “Our staff attributed that to the excessive heat and the fatigue.”
But the extreme heat came with a bonus: fly balls carried. “It was common knowledge that the ball travels better in the heat, and it’ll travel better in the summer than in April or May,” Wheat says. “Oakland’s a perfect example of that. It’s cool and dry there at night, and it’s very hard to hit a home run. That was a place where everybody said they liked playing day games because that was the only chance they had to hit a homer.”
Wheat’s anecdotal evidence is backed by physicist Alan Nathan, whose current research is on baseball—specifically, the collision of the bat with the ball and the aerodynamics of a baseball in flight. Nathan, a professor emeritus of physics at the University of Illinois, says, “You’ll see the ball, on average, travel a little bit farther in Texas than in other venues. Pitchers don’t want to play there, batters do. It’s a hitting environment.”