Corked bat

In baseball, a corked bat is a specially modified baseball bat that has been filled with cork or other lighter, less dense substances to make the bat lighter. A lighter bat gives a hitter a quicker swing and may improve the hitter's timing. Despite popular belief that corking a bat creates a "trampoline effect" causing a batted ball to travel farther, physics researchers have shown that this is not the case. In Major League Baseball, modifying a bat with foreign substances and using it in play is illegal and subject to ejection and further punishment.