Edgar Martinez once used a corked bat. The legendary Mariners designated hitter made his confession to The New York Times in 2003, a few days after Cubs slugger and habitual cheater Sammy Sosa was busted for swinging doctored timber. Of course, while Sosa was caught red-handed using his corked bat in a game against the Tampa Bay Rays, Edgar told reporters that he only dabbled with cork a decade prior during a stint in the Puerto Rican winter leagues. Even then, Seattle's foremost masher added, boring out the barrel of his bat and stuffing it with cork "didn't make any difference" in his performance. Now, nearly another decade later, there's finally some scientific evidence to back Edgar up.
Smith concluded that corked bats, a cheating technique that's nearly as old as the game itself, can indeed help a struggling hitter, just not for the reasons they have historically suspected. The general assumption among baseball aficionados is that hollowing out a cavity in a wood bat and filling it with a lightweight, buoyant material such as cork produces the same "trampoline effect" that makes baseballs rocket off the barrels of aluminum bats.
To test this hypothesis, Smith and Alan Nathan, a professor emeritus of physics at the University of Illinois, corked a bat and fired baseballs at it from a cannon. (No, that doesn't mean Randy Johnson's left arm.) The researchers then measured the speed at which the balls bounced off the barrel and found that it's actually slower than the ricochets off a normal, regulation bat.
But, though the experiment debunked the trampoline effect, Smith explains that there are still other factors to consider when it comes to the perceived advantages of corked bats. Corking makes the bat lighter, and therefore hitters can theoretically react more quickly to pitches and make better contact than they would otherwise. This, Smith says, is generally true. The flip side is that a lighter bat has less inertia, and therefore hitters will have less power than they would otherwise.
"If they're trying to get that long ball or home run, they should go for as heavy a bat as they can possibly swing," Smith tells Seattle Weekly.
Based on the tests in WSU's "sport sciences laboratory," Smith says that short of using bats made from exotic woods or composite materials, there's very little that big-league hitters can actually do to cheat and get meaningful results at the plate. Even tinkering within the rules--such as using bats made from ash, maple, or hickory--makes little difference when swing comes to hit.
"People make a lot of noise about having the perfect wood, but they really don't do much for you," Smith says. "Having good-quality wood will help you, but the idea that maple is this super-magic wood or something of that sort, that just doesn't really play out."
According to Smith, the one thing nobody has tried yet that might make a difference is the shape of the bat. He suspects that "having a big glob of weight" in the tapered section of the bat handle would reduce the amount of bend during the swing. "That would tend to increase performance a bit," Smith says, "especially if they're hitting the ball off the sweet spot."
Of course, Smith also acknowledges that his imaginary bat would look so ridiculous that "nobody would want to use it anyway." In the end, it comes down to intangibles, the subjective criteria that tend to drive stat obsessives and scientists crazy.
"If a person feels what is in their hands is better than what they had before, you have a psychological advantage," Smith says. "We know that psychology is important in sports. Most teams have a better average at home than they do away. Why is that? Because their bed is more comfortable? The fans? There's factors that we can't quantify in a lab."
Edgar Martinez, for example, was particularly fond of light bats. Here's hoping that doesn't mean they were corked.