Chapter 5, Section B
The channels or gutters are located on both sides of the bowling lane and pin-deck. They extend from the foul line to the pit. From the foul line to the headpin, they are rounded or concave to allow errant bowling balls to roll freely to the pit.
At the pindeck, they are flattened and squared off, as well as lowered to prevent excessive rebounding of pins and to keep the ball from accidentally rolling over the pindeck.
The width of each channel is dependant on the width of the lane, as the total playing surface measured from the outside of one gutter to the outside of the other gutter must be 60 inches.
The minimum width must be at least 9 inches and the maximum 9 1/2 inches. This is due to the tolerance at on the lane width of 41 or 42 inches and the GO inch requirement./p>
The channels are intended to keep bowling balls within their' playing area, and to determine legal pinfall Balls rolled in the gutter are legal deliveries, but no pins can be scored once the ball is in the channel. A channel or gutter ball counts as a ball rolled during a game.