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 have a decimal component (numbers to the right of the decimal point) discard all numbers to the right of the decimal point, leaving only a whole number, as rounding any decimal number equal or higher than 0.500, "up" to the next highest whole number when calculating averages is prohibited by USBC rules on scoring in tenpins. As of the 2014–15 season, approximately 1.57 million people compete in bowling leagues in the United States. At its peak in 1980, over eight million men and women competed in leagues throughout the United States. In ten-pin bowling there are two major world organizations