Madison, Wis. ? When it comes to baseball, Dave Kretschmann always keeps his eye on the bat.

A casual fan whose loyalties are split between the St. Louis Cardinals and Milwaukee Brewers, Kretschmann watches games much differently than he did three years ago.

When a player steps to the plate, Kretschmann isn’t thinking about the pitching matchup or second-guessing the manager. He’s focused on the brand, shape and composition of the bat the player has in his hands. If Kretschmann sees something he doesn’t like, he worries about whether it’s about to shatter into flying fragments that could hurt a player, a coach or a fan.

“I know too much now,” he said.

Faced with an epidemic of dangerous broken bats in 2008, Major League Baseball turned to the U.S. Forest Service for help in solving the problem. And who knows wood better than the Forest Service?

Led by Kretschmann, a research engineer at the Forest Service’s Forest Products Laboratory near the University of Wisconsin campus, the partnership appears to be working.

Since the broken-bat issue reached its peak in the middle of the ’08 season, the overall number of broken bats has remained relatively steady. But Kretschmann has tracked an approximately 50 percent reduction in the most dangerous type of broken bat, where a piece or pieces of the bat literally come flying off the handle after contact with the ball.

Kretschmann calls it a “multiple-piece failure.” Others in the game call it just plain dangerous.

“They’re flying into stands with the jagged edge sticking out, they’re flying into the ground all over the field,” Brewers manager Ron Roenicke said.

Dan Halem, MLB’s senior vice president of labor relations, credited Kretschmann for leading the way in making significant steps for safety.

“It’s a pure safety issue,” Halem said. “The only interest that we have here is making sure that there are no safety incidents with on-field personnel or fans because of a broken bat.”

After sorting through thousands of broken bats — including nearly every bat that broke in the second half of the 2008 season — Kretschmann and colleagues at Harvard and the University of Massachusetts Lowell identified issues that made bats more prone to shattering.

Many in baseball have blamed the rise of maple bats.

“I do a lot of woodworking,” Roenicke said. “I work with maple and I work with ash. Ash, you can take a screw and drill right through it. Maple, you do that and it busts. It’s a fact.”

Indeed, research showed that bats made of particularly low-density varieties of maple instead of ash are more prone to multiple-piece failures. There also are problems with the shape of bats preferred by some of today’s sluggers — bats with thin handles and thick barrels; Kretschmann calls them “tennis rackets.”

But those aren’t the biggest problems. Kretschmann said the main issue with bats that break into multiple pieces is the so-called “slope of grain” in the wood.

Ideally, a bat would be made so the grain runs perfectly straight along the length of the bat. But if it’s off by more than three degrees from parallel, the bat can lose about 20 percent of its strength and Kretschmann found himself examining bats that were off by 10 degrees or more.