More than 40 million Americans will play organized softball this summer. It's the most popular team participation sport in the United States, according to the Amateur Softball Association. The Institute for Preventative Sports Medicine notes that softball also results in more emergency room visits than any other sport.

Most of those hurt suffer only minor injuries. But every so often, someone's face is broken.

It happened to a Stockton man in 2006 and a Sacramento woman in 2007. Both were pitching when they were struck by line drives hit from the barrels of composite metal bats. The bats were rumored, and in one case proved, to have illegal modifications that increase power and batted-ball speed.

"I never even saw the ball," said Tonya Bagwill, 40, a search-and-rescue training coordinator with the Governor's Office Of Emergency Services. "I just remember picking myself up off the ground, and I was bleeding all over the place."

Bagwill's nose and cheek bone were broken, caus......