| A bowling ball is a round ball made from | | | | and gravity becomes a factor that can range |
| rubber, urethane, plastic, reactive resin | | | | from subtle to perhaps amazing. These |
| (solid, particle, or pearl) or a combination | | | | environmental influences can be segregated as |
| of these materials which is used in the sport | | | | either lane conditions or ball |
| of bowling. Ten-pin bowling balls generally | | | | characteristics. Additionally, a bowling ball |
| have a set of three holes drilled in them, | | | | is not an absolutely uniform |
| one each for the ring and middle finger, and | | | | sphere—the gripping holes (and |
| one for the thumb; however, rules allow for | | | | sometimes a balance hole) alone make that |
| up to five finger holes. A five-pin bowling | | | | impossible. |
| ball has no finger holes and is smaller so | | | | |
| that the bowler can hold the ball in the palm | | | | Bowling ball materials, during the history of |
| of their hand. Candlepin bowling balls also | | | | the USBC, have evolved from wood, to rubber, |
| fit in the hand, but are lighter than | | | | to plastic, to urethane, to reactive |
| five-pin balls. | | | | urethane, to particle, and to epoxy. Wood |
| | | | balls are now just museum pieces. Rubber |
| Most bowling alleys provide free balls for | | | | balls are almost as hard to find - you may |
| patrons to use, called house balls, although | | | | still see them offered to casual bowlers at |
| avid bowlers may purchase their own. These | | | | bowling centers, from their racks for those |
| are often customized, and can feature | | | | who don't own their own ball. Bowling balls |
| specially sized finger holes (in the case of | | | | have been constructed with a core made of one |
| ten-pin balls) or monograms. Most people can | | | | material, a spherical coverstock ("cover" or |
| easily buy a bowling ball that is at least 1 | | | | "shell") and a "pancake" weight block of |
| to 2 pounds heavier than they used as a house | | | | denser material intended to compensate for |
| ball. | | | | the gripping holes. |
| | | | |
| Bowling balls come in a wide variety of | | | | One of the most contentious issues that has |
| colors, and are often either a single flat | | | | arisen is whether significant restrictions |
| color, a swirl-like design of multiple | | | | should be imposed on bowling ball technology. |
| colors, or a single color with an iridescent | | | | Other considerations have been noted with |
| look. It is even possible to obtain | | | | regards to the weight of the bowling pins, |
| transparent bowling balls, painted in such a | | | | lane oiling techniques, and with the |
| way as to make it appear as though an object | | | | construction materials and techniques used to |
| is inside. Some objects have included skulls, | | | | build bowling lanes. |
| footballs, and baseballs. | | | | |
| | | | Finger holes and grips |
| Inside the ball is a core which makes each | | | | |
| ball do something different. These cores are | | | | The way the finger holes are arranged on the |
| dynamically imbalanced to cause the ball to | | | | ball surface changes the core dynamics; this |
| try to stabilize as it is rolling down the | | | | will change how the bowling ball hooks down |
| lane. This makes the ball roll over a | | | | the lane. |
| different point on the surface every time it | | | | |
| revolves and "flares" or causes multiple oil | | | | There are only two different types of bowling |
| rings. | | | | grips for bowling balls: conventional, and |
| | | | finger tip, all other grips of any name i.e.: |
| Ten-pin balls | | | | Sarge-Easter Grip and Semi finger tip are |
| | | | derivatives or these two. In a conventional |
| Regulation ten-pin bowling balls must weigh | | | | grip, the bowler's ring and middle fingers |
| no more than 16 pounds (7.2 kg) (governing | | | | are placed into the ball up to the second |
| bodies do not regulate how light a bowling | | | | joint, while in a finger tip grip the ring |
| ball may be) and have a diameter of 8.5 | | | | and middle finger holes are made to accept |
| inches (21.6 cm). Since the physical size of | | | | the bowler's fingers only up to the first |
| regulation balls is the same, while the | | | | joint. Semi-finger has the bowler put their |
| weight may differ, lighter balls are much | | | | fingers in an unhappy medium between |
| less dense than heavier ones. Thus, balls | | | | conventional and finger tip. A finger tip |
| under 10 pounds will actually float when | | | | grip requires more strength, but it allows |
| placed in water. | | | | the bowler much more control in how the ball |
| | | | rotates after it is released. For the players |
| The behavior of a rolling ball on a surface | | | | with extremely high rates of revolution ("rev |
| is controlled by several factors, the most | | | | rates") and skill level, a Sarge-Easter Grip |
| obvious being the bowler's delivery. In the | | | | may be an option. This is when the middle |
| delivery, the bowler can advantageously use | | | | finger is drilled to finger tip depth, while |
| or fight (intentionally or unintentionally) | | | | the ring is drilled to the conventional |
| the force of gravity. After the ball is on | | | | depth. It allows players with high revs to |
| the surface of the lane, a complex | | | | change their axis tilt and allow more forward |
| interaction of friction, gyroscopic inertia | | | | roll as to keep the ball from over hooking |