Are aluminum baseball bats too dangerous and should therefore be banned from use in league play?
On July 25, 2003, 18-year-old Brandon Patch, a southpaw pitcher for the Miles City Mavericks American Legion team, was killed after a line drive rocketed off an aluminum bat and struck him in the head.
Now, almost two years later and in an attempt to prevent future tragedies, his parents and others are on a crusade to see the national pastime, at all levels, revert to wood bats.
The data is inconclusive on the extent to which aluminum bats increase the risk of serious injury to pitchers and infielders relative to wooden bats. Testing has been limited to laboratories, and therefore does not address actual game situations (baseballs are pitched at 65 mph rather than 85, a more accurate speed for college pitching), fatigue, air resistance, etc. But there is no doubt that aluminum bats allow for faster bat speed (lighter bats and reduced moment-of-inertia allow for faster angular velocity), a larger sweet spot, and enhanced trampoline effect (the bat compresses rather than the ball, reducing the energy on the ball lost from impact with the bat) cause a pitched ball to come off the bat faster relative to a wooden bat. Here's one explanation of the physics of baseball bats. Here's some information submitted to the Consumer Product Safety Commission on baseball bat safety. (PDF file)
But it's not enough to answer that baseball is safer than other participation sports, and therefore aluminum bats are relatively safe. The question is whether aluminum bats sufficienty increase the risk of serious injury to pitchers and fielders from hit balls coming off the bat faster relative to wooden bats. This then has to be weighed against the added value from aluminum bats relative to wooden bats in terms of game dynamics (more home runs, more runs per game). (The graph below shows the average distances of balls hit off of wooden and aluminum bats.)
The NCAA has increased regulations of aluminum and composite bats used in college baseball, but this was an effort to increase the defensive nature of the game and not to reduce the risk of injury to pitchers.
Addendum: Would I ban aluminum baseball bats? No, but as a coach I also would not allow kids younger than 12 to use them, and those older than 12 could use aluminum bats in games only. ("in games only" simply to take away the competitive advantage teams using aluminum bats would have. For kids younger than 12 I wouldn't care so much about the competition; I'm concerned more with player development and learning strategy.)
Far more suffer serious injuries from sliding head first and being hit with thrown balls than from hit baseballs. The first is easily rectified: Sliding head first is not allowed in Little League and I would neither teach it nor allow it for high school-age players. The latter is simply part of the game and unavoidable without seriously altering the nature of baseball.