Fast pitchers push batters' ability to respond

A white blur explodes from the left hand of Reds reliever Aroldis Chapman. By the time the batter is able to see the speeding ball and his brain decides whether to react, 130 milliseconds have elapsed. The ball is one third of the way to the plate.

Then it takes another 100 milliseconds or so for the batter's muscles to tense up, and 150 milliseconds for him to swing the bat, and . . .

Thunk! The ball, after 380 milliseconds, has already landed in the catcher's mitt.

Such are the parameters at the outer limits of elite human performance. Chapman threw a 105.1 m.p.h. fastball last month against the San Diego Padres, the fastest yet recorded with sophisticated new camera-based technology used by Major League Baseball, and such speeds push the limit of how fast a batter can react. Skilled professional hitters can handle a triple-digit fastball, especially if the pitcher doesn't mix in off-speed stuff, but 105?

Good luck, said James A. Ashton-Miller, a professor of mechanical and biomedical engineering at the University of Michigan.

"He's going to definitely have to be focusing on the task, and not worrying about what's for dinner," Ashton-Miller said of the batter.

Such speeds also are pushing what the pitcher's elbow and shoulder can handle - a limit that scientists have measured in part by testing cadavers.

How does Chapman do it? He has at least two characteristics in his favor. Like many fireballers, he is tall, listed at 6 feet 4. The longer the various body parts - trunk, arms, even fingers - the more torque the pitcher can exert on the ball, assuming he has the muscle strength and coordination, said Glenn S. Fleisig, research director at the American Sports Medicine Institute in Birmingham, Ala.

Former Phillie Pedro Martinez, though not terribly tall, was said to generate his speed as a young pitcher in part because of his long, whiplike fingers.

Another key to speed, Fleisig said, is flexibility. When preparing to unleash high heat, Chapman and other top pitchers snap their forearms backward so they are fully horizontal to the ground.

Fleisig warned that in adults, this flexibility cannot be improved with training. The range of motion is due to genetics and to how much a player throws when growing up.