Bowling ball random when impacting a full rack of pins on the first delivery of a frame, and sometimes when hitting downed "dead wood" pins on subsequent deliveries—the candlepin bowling sport is the only major one that allows fallen pins, provided no part of any fallen pin extends more than 24 inches (61 cm) forward of the head-pin spot, to remain on the lane's pindeck to be used in knocking down more pins with the next ball delivery in the same round—up to three balls are delivered, much as in duckpins, in each round of candlepins for one bowler. Bowling ball A
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