Why Baseball Pitchers (And Other Athletes) Are Getting Taller

Jul 10, 2013

The falling forward motion the thrower affects the amount of force applied to the ball.
Credit Adrian Bejan

Scientists have known for years that the athletes topping the podium in speed sports, like swimming and running, have grown taller over the past century. Now, new research from Duke University shows that athletes in a range of other sports, including certain team sports, are following a similar trend.

Adrian Bejan, an engineering professor at Duke, is the lead author of a paper  called “The Constructal Evolution of Sports with Throwing Motion: Baseball, Golf, Hockey, and Boxing.” In it, he looks at what makes athletes who throw balls (baseball pitchers) and punches (boxers), or use a stick to propel an object (golf and hockey players), good at their sport. As it turns out, height matters; the taller the athletes are, the more force they have to throw themselves forward and make a ball fly faster. This trend follows what Bejan calls constructal law.

“According to the constructal law predictions, the larger and taller machine, like medieval trebuchets, is capable of hurling a large mass farther and faster," Bejan said in a statement from Duke. "The other players on the baseball field do not have to throw a ball as fast, so they tend to be shorter than pitchers, but they too evolve toward more height over time. For pitchers, in particular, height means speed."

Because the statistics of professional athletes are meticulously recorded, they are are an excellent sample pool for scientists studying the evolution of the the human body in sports.

Adrian Bejan, lead author of the study
Credit Duke University Photography

Former Major League Baseball player Randy Jonhson stood six feet, ten inches tall and won five Cy Young awards (the highest award given to a pitcher). He also set the record for strikeouts for a lefthander. If baseball keeps following the constructal theory trend, as Bejan concludes, it’s possible that the next few centuries will see more pitchers like Johnson.

The results of his analyses were published online in the International Journal of Design & Nature and Ecodynamics.