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 is on top of the ball with two fingers in the 12-o'clock position and the thumb ending in the 6-o'clock position, at which point the fingers and thumb release the ball simultaneously. The forearm also creates spin and pushes the ball onto the lane. Spinning is difficult to master, and can cause injury if not done properly. Using a lighter bowling ball (10 to 12 pounds) with a completely rounded core is recommended, along with a conventional grip. Spinning causes results like a weak 5-pin more frequently. The backup style of bowling is where the bowler will flick their wrist