Cincinnati pitcher Aroldis Chapman pitched a fastball that clocked in at 101 miles per hour at Tuesday night's All-Star game, the fastest pitch of the night. Even though batter Adam Jones missed, imagine if he had hit the ball, but with the wrong part of the bat.
"If you hit it away from the sweet spot, you'll feel pain right underneath the fleshy part of your hands between your thumb and forefinger," said Dan Russell, a professor of acoustics at Penn State University.
Russell has been working with sports equipment companies to engineer a better metal bat for young players just getting introduced to the sport. The newer bats dissipate some of the pain caused by a bad hit.
The stinging sensation of a bad hit is caused by the vibrations that ripple through the bat after making contact with the baseball. Russell says that the bat actually flexes back and forth immediately after hitting the ball. "There are a number of patterns in the shapes that the bat vibrates with," he told ABC News.
Two of those shapes are the main components that causes a players hands to sting. However, a small area on the bat, about 5-7 inches from its tip, is the sweet spot. If a batter manages to hit a ball right on the sweet spot, the vibrations don't travel down to the hands.
In addition to protecting the batter's hands, the sweet spot also sends the baseball flying farther. "Less energy is lost in the bat's vibration," said Alan Nathan, owner of the website The Physics of Baseball and a retired professor of physics at the University of Illinois. "Not only does it feel better [on the hands], but hits the ball harder."
Of course, consistently nailing the baseball in the right place is no trivial task. "Even in Major League Baseball, you see people mishitting the ball and they have the best hand-eye coordination of anyone in the game," said Nathan. "Otherwise, there would be more people hitting home runs."
Since it's hard enough to hit a baseball, let alone right on the bat's sweet spot, Russell researched a way to diminish the excessive vibrations caused by a bad hit. Working with Marucci Sports, he designed a vibration absorber that's built into the knob of of their metal and composite baseball bats.
Inside the knob of the bat is a metal mass surrounded by a rubber spring. When the bat hits the ball and starts vibrating, some of that energy gets transferred directly to the mass and spring, rather than through the handle. Marucci Sports and Russell first introduced the system in 2007, though it took a couple years of refining until they finally made a product that met their expectations.
Russell sees it as a way to keep younger kids interested in Little League. "If every time they hit the ball it hurts, they don't want to play anymore," he said. "We want to put a device in their hands and give them confidence."
For all of Russell's work improving baseball bats, he himself has not been a lifelong baseball fan. "I like watching baseball, but I only started watching after marrying my wife, who's a huge Yankees fan," he said. "I'm just interested in things vibrating."