If the NFL's New England Patriots did deflate their game balls, even slightly, it would have given them an advantage during their playoff win this past weekend, said Chang Kee Jung, who teaches a course on the physics of sports at Stony Brook University in Long Island, New York.
Ninety percent of the time, you want a ball that’s properly pumped to give you the furthest throwing trajectory, Jung said. But when in bad weather, a squishier ball is easier to throw and catch.
“On cold days, a fully inflated ball is ... hard as a brick,” he said, “Having a softer ball would allow the quarterback to throw more accurately in a tighter spiral and make it easier for the receiver to catch.”
If a quarterback has small hands, a mushier ball would offer even more of an edge in the rain, making it easier for him to grip, Jung added.