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 off center without falling. The pins must show the name and mark of the maker, either "USBC Approved" or "BTBA Approved" and appear uniform. The maximum diameter of the ball is and the circumference of the ball must not be more than , and the ball cannot weigh more than 16 pounds (7.26 kg). Generally, the lightest ball available for use is 6 pounds (2.72 kg). The ball must have a smooth surface over its entire circumference except for holes or indentations used for gripping the ball, holes or indentations made to bring the ball back into compliance with weight-distribution