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 it is damaging the integrity of the sport. Before 1970, nearly all bowling balls had a hard rubber surface. As the coatings applied to wood lanes changed from softer lacquer to a harder urethane in the early 1970s, the first polyester balls became widely available. Subsequent changes since the early 1980s — particularly with urethane surfaced and later "reactive" resin or composite ("particle") surfaced bowling balls—have been altering the physics of how the ball rolls and strikes the pins. Coupled with synthetic lane surfaces and advanced oiling machines presenting the opportunity to lay out lane oil patterns that make targeting