The Swing of Things
In 1970's baseball evolutionized its play by playing with aluminum bats rather than wooden bats. Massachussetts Interscholastic Athletic Association thought about banning aluminum bats at a high school tournament and then in 2006 there was a bunch of law suits about the unfair advantage that aluminum bats provide. Aluminum bats are hollow, the hitting surface is longer and the bats don't break. However, a study has shown that sometimes the aluminum bats do not out preform the wooden bats; the rebound speed depends on the area of which the ball hits the bat.