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 set by human pinsetters or "pin boys", but with the invention of the semi-automatic pinspotter in 1936 (usually just the "spotting table" component), the process became much easier. In 1946 AMF Bowling launched the first commercial fully automatic pinspotter, the AMF Model 82-10, followed closely by the more developed 82–30 model (still in common use in the 21st century) to replace the earlier Brunswick semi-automatic and fully manual bowling establishments. Brunswick itself introduced its own "Model A" automatic pinspotter design to bowling centers in 1955, and along with its successors (A2 and "JetBack", both with quicker delivery of returned balls