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