Ten-pin bowling ramp in which a bowler will use two hands and push the ball down the ramp onto the lane. There are three widely recognized delivery styles used while the ball is released onto the lane. (See article: Bowling form.) These are the "stroker", "cranker" and "tweener" styles. Lesser used (and newer) styles include "no-thumb" and "two-handed". Strokers often keep their shoulders square to the foul line and their backswing generally does not go much above parallel to the ground. This type of delivery reduces the ball's rate of revolution, thus decreasing its hook potential and hitting power. Strokers rely on
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