Bowling form

PBA bowler John Furey demonstrates a conventional (one-handed) delivery, which involves the thumb and two fingers of one hand. Finger rotation surrounding the instant of delivery can induce axis rotation (side rotation), causing the ball to hook (curve).

In the sport of ten-pin bowling, there are many different ways in which to deliver (known as a "throw" or "roll") the bowling ball in order to advance it toward the pins in an accurate and powerful manner. Generally, there are three basic forms of 10-pin bowling. The most basic form is known as stroking, which is the most classic form. The most powerful form is known as cranking, which imparts great leverage and maximum rotation on the ball, but sacrifices accuracy. In between the two is the domain of the tweener, who has characteristics of both, but does not truly fit into either category. A well-known variant of "tweening" is the power stroker.

Power stroking is often very similar to cranking and bowlers can often fit in either category, therefore bowlers that use one of these two styles are often simply known as power players. A fourth style, known as helicopter, spinning, or UFO, is a style that is used to great effect in Asia. Finally, many modern bowlers have changed to a one- or two-handed no-thumb delivery. Most of the various forms use different wrist and hand positions and rely on different timings and body positions to accommodate the differences in each style of release.