Because of the trampoline effect that occurs when a baseball hit an aluminum bat, aluminum bats can hit a ball significantly farther than wooden bats can.

In aluminum bats, a double-walled bat was introduced in the late 1990s.

Aluminum bats are lighter and stronger than wooden bats.

The trampoline effect has been experimentally tested, and results show that composite bats outperform all aluminum bats.

As has been chronicled in slow-pitch softball recently, composite bats have out-performed standard aluminum bats.