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Skinny wooden bats used in Major League Baseball have to withstand up to 8,000 pounds of force when they make contact with the ball.

09/17/2013
By Edwin L. Aguirre

As baseball fans know, nothing beats the sight and sound of a player’s bat solidly hitting the ball, sending it flying off into the bleachers and beyond for a home run.

But do you know what happens to the wooden bat when it strikes the ball?

“A 90-miles-per-hour pitch impacting a bat swinging at 70 miles per hour can exert a force greater than 8,000 pounds,” says Patrick Drane, assistant director of the University’s Baseball Research Center

“This peak force is exerted for a small fraction of the 1,000th of a second that the ball and bat are in contact,” explains Drane. “When the ball impacts away from the bat’s ‘sweet spot,’ much of the energy goes into vibrating the bat. These vibrations can cause even the strongest of woods to break.”

The Baseball Research Center — featured in a one-page article written by National Geographic editor Johnna Rizzio in the magazine’s September issue — has been studying the durability of wood bats for Major League Baseball (MLB) for more than five years. The Center’s specialized tests include using an air cannon to generate collision velocities up to 180 miles per hour and utilizing a high-speed video camera to analyze the impacts and breakage.

According to the National Geographic article, major leaguers broke 1,697 bats between July and September 2012. Part of the problem has to do with the kind of wood used in making the bats, with more players preferring maple over ash. 

“Ash had been the most popular wood species used in Major League Baseball bats for more than a century,” notes Drane. “In the past decade, however, maple bats have become much more popular among players because they like the hardness, look and feel of the bats, and some actually think maple bats perform better. Ash and maple bats produce the same batted-ball speeds.” 

As maple bats increased in popularity, the number of bats splintering into multiple pieces was perceived to increase, so the MLB began studying ways to improve the bats’ durability without changing the players’ approach to the game.

“Strict grading of the wood, along with inspection, training and other regulations, has been implemented over the past five years and has resulted in a significant reduction in the number of multi-piece failures that occur during games,” says Drane. “All wood, not just ash and maple, are now regulated to ensure that the best-quality raw material is used in making bats for the professional baseball players.”

Drane adds that ash forests that supply bat manufacturers are also being threatened by the “emerald ash borer,” an invasive insect species that is killing the trees.

“Ash, therefore, will be in lesser supply in the future,” he says. “The effect of this change in the supply will necessitate the use of alternatives to maple, such as yellow birch.”