Bowling ball Bowling ball A bowling ball is a piece of sporting equipment used to hit bowling pins in the sport of bowling. Balls used in ten-pin bowling are typically hard spheres with three holes drilled in them, one each for the ring and middle fingers, and one for the thumb. Regulating bodies such as the USBC maintain requirements for the properties of bowling balls, including size, hardness, and number of holes, as well as maintaining a list of bowling balls approved for competitive play. Other bowling balls, such as those used in five-pin bowling, candlepin bowling, and duckpin bowling are smaller,
Ten-pin bowling determining success in the sport of bowling." The USBC completed data analysis and released a lengthy report on its website (www.bowl.com) to the public in the spring of 2008. As of April 1, 2009, The USBC now regulates the chemical surface roughness of all bowling balls manufactured for certified ten-pin bowling. This specification is a direct result from the ball motion study, as the surface roughness of the coverstock of a bowling ball was the number one variable (out of 18) that affected the strength (how much a ball hooks) of a bowling ball. The radius of gyration specification has