Baseball has a home run conundrum, but experts aren't blaming the balls

Chemical and Engineering News (June 21) MLB players can send baseballs screaming off their bats at nearly 200 km per hour. Under that type of abuse, no synthetic material that Rawlings has tested performs as well as what the company’s already using, Smith-Stephens says.And performance is the primary concern, whether you’re a batter, a ball manufacturer, or even a juiced-ball conspiracy theorist. The key performance metric for ball aficionados is the coefficient of restitution, or COR, which people in the biz pronounce as “core.” The COR for any object falls between 0 and 1, explains nuclear-physicist-turned-baseball-physicist Alan M. Nathan of the University of Illinois, Urbana-Champaign (UIUC). If you drop the object and it doesn’t bounce at all, it has a COR value of 0. If it returns to its original height, its COR is 1.