Hook (bowling)

True scale diagram: A straight path, even one starting from the extreme outside corner of the lane, results in an angle of entry of at most 1.45°. Larger entry angles (shown in diagram) are achievable when hooking (curving) the ball. Larger entry angles have been shown to be generally more favorable for achieving strikes.[1][2]
• Top: Simplified representation of the skid, hook, and roll phases of bowling ball motion.
• Middle: Hook is enabled by side rotation as the ball frictionally engages dry lane surface as it nears the pins.
• Bottom: Though the ball's translational speed down the lane (brown arrows) decreases, its rotational speed (yellow arrowheads) increases.

Technological advances since the early 1990s in ball design have allowed dramatically increased hook potential and strike frequency, without requiring additional skill on the part of bowlers.[3]

A hook in ten-pin bowling is a ball that rolls in a curving pattern (as opposed to straight). The purpose of the hook is to give the ball a better angle at the 1-3 pocket (right-handers) or 1-2 pocket (left-handers.) to achieve a strike. When a ball is rolled straight, hitting the pocket must be precise. By hooking the ball, the ball will hit the pins with more force, producing better carry - especially on the 5-pin during a strike ball. Straight roll - even when it hits the pocket, will tend to leave a tap such as the 5-pin on a light hit, or the 10-pin if the ball was just slightly right of center pocket or with inadequate entry angle. A hook ball can achieve strikes with less precise hits.

A hook ball can also help the bowler shape the shot on challenging oil patterns.

In duckpin bowling, candlepin bowling, and nine-pin bowling, hook potential is greatly reduced since the balls are generally rolled much faster and thus have less time for a hook to develop.

  1. ^ Benner, Mours & Ridenour 2009.
  2. ^ Freeman & Hatfield 2018, Chapter 8 ("Why Does My Ball Hook?").
  3. ^ Stremmel, Ridenour & Stervenz 2008.