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 speed and certain type of bowling balls. If a bowler has a specific form of bowling suitable for a specific oil pattern, coupled with the right bowling ball, his margin of error is highly increased versus other bowlers. The result is that sometimes the bowler throwing the more accurate shot loses to the bowler who has created a larger "target area". Some advanced bowlers simplified this to: "To a large degree, the equipment and oil pattern determines the winner." At the end of 2007, the USBC completed a two-year study on bowling ball motion and how advanced, high-tech equipment may