Effect of grip-enhancing agents on sliding friction between a fingertip and a baseball

Abstract Friction between a pitcher’s fingers and the leather surface of baseball is key factor that influences ball delivery, causing Major League Baseball in United States to recently enhance enforcement rules banning unauthorized use friction-enhancing agents or sticky substances. Here, we examine how application rosin powder substances alters friction coefficient fingertip baseball. We find increase which can positively affect spin rate, while has advantage keeping consistent within individuals. Additionally, baseballs used by Nippon Professional Organization Japan are less slippery compared with ones Baseball, suggesting grip-enhancers may have larger impact on for Japan. Furthermore, our results indicate changing characteristics made from friction, reducing