Some good news for Sammy Sosa fans still whispering, "Say it ain't so." Back in 2003, Sosa was caught using a corked bat—a normal wooden bat hollowed out in the center and stuffed with lighter cork material. That embarrassing incident did happen, and it does go against baseball rules. But, according to physicists at the University of Illinois and Washington State University, a corked bat probably doesn't offer much of an advantage. Sure, Sosa technically cheated. But he didn't actually cheat in a practical sense, they say. At least, not by altering his bat.
There was some anecdotal information from players that there's something like a 'trampoline effect' when the ball bounces off a corked bat," says Nathan, one of the authors of the new study. So the researchers hollowed out a bat, stuffed it with bits of cork and fired a ball at the bat from a cannon. If anything, the ball came off the corked bat with a slower speed than off a normal bat. Less velocity means a shorter hit. Their conclusion: the trampoline effect was bogus.
But there was another way corking might work: a corked bat is a few ounces lighter than an unadulterated one, and a lighter bat means a batter can swing faster, which means he can generate more force and hit the ball farther. Right? Not quite, as it turns out.
A batter indeed can swing a lighter bat faster, but a lighter bat has less inertia. So there's a trade-off, says Lloyd Smith, an associate professor of engineering at Washington State University and a co-author on the paper. By once again firing a ball at a bat at WSU's Sports Science Laboratory, the researchers found that a heavier bat still hit the ball harder (and therefore farther) than a lighter, corked bat. "Corking will not help you hit the ball farther," says Smith.
Smithsonian: The Physics of Cheating in Baseball