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
Bowling ball lighter, and without holes, so that they may be held in the palm of the bowler's hand. Most bowling alleys provide balls for patrons to use within the establishment, often referred to as "house balls." Key properties of ten-pin bowling balls include surface friction, porosity, and mass distribution, which affect the motion of the ball as it rolls. These properties are varied to control how much a ball will slide through the oily surface of a typical bowling lane, and how easily a ball will change direction when the roll is combined with rotational motion. Friction and porosity are variables