Determined to cut down on risky headfirst slides, the Houston Astros are doing something about it. They've put a unique policy into effect for all of their minor leaguers: If any of them try it at first base or home plate, their manager is required to pull them immediately.

All-stars Roberto Alomar, Derek Jeter and Scott Rolen have gotten hurt in the past going headfirst. Junior Spivey, Rafael Furcal and Carl Everett were banged up this year.

"We tell our guys that it's a low-percentage play, and that you can get injured doing it," Astros Director of Player Development Tim Purpura said.

The Astros make exceptions for plays in which runners go headfirst trying to avoid tags. Diving into second base and third base is allowed, though not encouraged.

Purpura said the policy went into effect after Roger Cedeno broke his hand on a headfirst slide into first base in May 2000.

The merits of going headfirst are debatable. Coaches, broadcasters and fans often rail against it, but Yale physics professor Robert Adair, the author of "The Physics of Baseball," once looked at the topic and saw a possible benefit.

"Runners tend to lean somewhat forward, and to go from a somewhat forward lean in the run to a headfirst dive has a certain efficiency," he said then.

In the first inning of a recent game for the Astros' Class A New York-Penn League team, the Tri-City ValleyCats, rookie Ben Zobrist dove headfirst into first and was called out in a close play. Manager Gregg Langbehn pulled him.

"He was trying to make a hustle play, and I can't fault him for that," Langbehn said. "But how many sprinters dive across the finish line?"

-- From News Services