Ten-pin bowling regulations, identification letters and numbers, and general wear from normal use. For much of the history of bowling, bowling balls were made using a three-piece construction method. Starting in the mid-1990s, however, most manufacturers switched to a two-piece method. In response to these innovative ball designs, the American Bowling Congress placed further restrictions on the technical characteristics of the ball such as the radius of gyration and hooking potential. A game of bowling consists of ten frames. In each frame, the bowler will have two chances to knock down as many pins as possible with their bowling ball. In games
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