Will wants to know my thoughts on the efficacy of corking. A bit of a disclaimer, I am neither a physicist nor a baseball player.

But here goes. First, I'm inclined to believe that corking does help. A little, maybe 4 feet on a 400 foot drive. Here's why. The Slate article argues that conservation of momentum is the formula that governs how the bat reacts. But momentum is not conserved in the collision any more than energy is. Not only are the ball and the bat not perfectly elastic, but if anyone reading this has ever hit a baseball knows, the bat vibrates in your hand. A lot, and sometimes painfully. If we start looking at the kinetic energy of the ball (which will determine its height and ultimate distance), it goes as the square of the velocity but only the first power of the mass. If the kinetic energy of the bat is higher (as will happen with a corked bat), there's more kinetic energy going into the collision and the ball will go farther. I'm inclined to go with the ballplayers here; there's an advantage, though not a very big one. If Matt's reading this, maybe he can resolve the controversy?

As for the question of why, then, shorter and thinner bats aren't prohibited, I think that's relatively easy. A longer bat has the advantage of providing greater torque when the batter hits the ball and gives the batter control of a much wider area of the plate, while a thicker bat increases the size of the all-important "sweet spot" (how many porn related Google hits am I getting from that phrase?) and again gives the batter control of more of the plate. No one is stopping me from going out to hit a ball with a sawed-off broomstick, but no matter how fast I can swing it, it's probably not a good idea. The problem is that corked bats are less dense, so you get the advantages of length and thickness without the disadvantage of more weight. It's a win-win situation for the batter.

It's not a huge advantage, really. But I think it's probably a little one. Will MLB now start inspecting (via X-ray) randomly selected bats at the beginning of the game? I don't think it would be a bad idea, really. If nothing else it might restore some credibility to baseball.

And that's way more physics than i ever want to think about again, thank you very much.