Bowling ball Bowling ball A bowling ball is a piece of sporting equipment used to hit bowling pins in the sport of bowling. Balls used in ten-pin bowling are typically hard spheres with three holes drilled in them, one each for the ring and middle fingers, and one for the thumb. Regulating bodies such as the USBC maintain requirements for the properties of bowling balls, including size, hardness, and number of holes, as well as maintaining a list of bowling balls approved for competitive play. Other bowling balls, such as those used in five-pin bowling, candlepin bowling, and duckpin bowling are smaller,
Ten-pin bowling a "shovel-pitch" from the side. A conventional bowling ball is designed to roll about a generally horizontal axis, and often the core is asymmetric so that the ball can hook naturally. However, in parts of Asia, the "spinner", "helicopter" or "UFO" release is more common. A ball spinning about a generally vertical axis of rotation spins like a top down the lane, and slides straighter, regardless of oil pattern. The ball takes an unconventional path along the front pins ("deflection"), creating domino effect pin action. The spin is generated by rotating the hand counter clockwise (right-handed bowlers) until the hand