Lanes and Equipment Back   The bowling surface is smooth, level, and made up of four parts: an approach, a lane, a pin deck, and a pit. The approach is an area at least 15 ft (4.6 m) long. Bowlers take several strides in the approach area to gain momentum before releasing the ball toward the pins. A foul line marks the point where players must release the ball down the lane. A player's feet may not touch or cross the foul line, even after the ball has been released. Lines and arrows in the approach area help bowlers aim their shots. These markings come 15 ft (4.6 m), 12 ft (3.7 m), and 6 in (.15 m) behind the foul line. The lane is a narrow area 60 ft (18.3 m) long and between 41 and 42 in (1 m) wide. Arrows in the lane 6 to 8 ft (1.8 to 2.4 m) in front of the foul line help bowlers aim their shots. Two slightly lower areas called channels, or gutters, run alongside the lane to catch wayward tosses. Each channel is 9.5 in (24.1 cm) wide. A ball that enters either channel is recorded as a scratch (worth zero points). The pin deck at the end of the lane has ten dots, called pin spots, that are 1 ft (.30 m) apart. Set on these spots, the pins form a 3-ft (.91-m) triangle with one pin in the middle and four on each side. (The pins at the points of the triangle are part of more than one side.) Pins are generally made of wood and plastic, and weigh between 3 lb 6 oz and 3 lb 10 oz (1.53 kg and 1.64 kg). Each pin must be 15 in (38.1 cm) tall. Pins have a narrow neck that gradually widens to a diameter of 4.75 in (12 cm) at the widest point, called the belly. The pin then tapers to a base 2.25 in (5.7 cm) in diameter. This design causes the pin to fall if tilted 10 degrees. The pit lies behind the pin deck and houses a special machine that sends the ball up a track that runs to the approach area. The machine also gathers the pins and resets them. Other equipment in the lane area includes a scoring desk, an air blower that bowlers use to dry their hands, and benches. The only individual pieces of equipment that bowlers need are bowling shoes and a bowling ball, both of which most bowling centers rent to customers. Bowling shoes have special soles that enable a bowler to glide during the approach. Most bowling balls have three holes, for the thumb and two fingers. Balls are made of various materials-rubber, plastic, urethanes, and combinations of these compounds. Although bowling balls come in assorted sizes and weights, those used in competition measure 8.5 in (21.6 cm) in diameter and weigh between 8 and 16 lbs (3.6 and 7.2 kg). Many bowling balls are black, but color can vary.