ver-increasing performance of metal bats has begun to affect the game at the college level and below. Aluminum bat makers have been exploring stronger and lighter metal alloys. The results include ever-lighter bats with thinner walls, and consequently higher bat speeds and even greater trampoline effects. A ball hit by these bats travels farther, faster.In addition, H&B has begun making a bat called the AirAttack in which a polyurethane bladder is inserted into the center hollow, then filled withpressurized nitrogen gas. The gas pressure in the bladder supports bat walls, pushing them out after they are deformed under impact. This support allows a much thinner wall and a greater trampoline effect. H&B has a softball bat called the Inertia, in which the interior of the bat contains a rolled-up steel spring that does the same thing. Batting averages and home-run production have gone up consistently at the college level as these advances have appeared.

Titanium was used briefly, but it was quickly prohibited because that metal's combination of high strength, light weight, and elasticity was clearly going to result in shattering all hitting records in all phases of the game. "You could actually grab the barrel of the bat in your hands and squeeze, and you could feel the bat give," says Manning, who adds: "The trampoline effect was enormous, and though titanium was banned, we learned a lot about how to make aluminum bats achieve the same effect."

Recently, a heated debate has broken out over the widespread use of aluminum bats in college leagues. Many in baseball fear that modern technology is creating a "superbat," which will irrevocably alter the game and endanger players. "Indeed," says Manning, "the rules committees are diligently looking at the performance of bats, and they have already put some limits on performance; they may well add more. They are not only concerned about the integrity of the game, the balance between offense and defense, but they are also concerned about safety." In fact, since interviewing Manning, the NCAA rules committee has decreed that many modern metal bats are dangerous to players and disruptive to the game.The high speed of the ball coming off the these metal bats has put pitchers in danger, as a line drive hit at them may be traveling too fast for them to get out of the way. And, according to Manning, the energy of a hit ball increases as the square of the velocity, so a fast hit can do more damage. As a result, the NCAA has ordered recently that bat manufacturers alter their designs to make bats heavier, with a smaller barrel. And baseball organizations from college to Little League are considering a return to a "wooden bats only" policy, though the fragility and expense of wooden bats may make such a move unfeasible.

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