Tenpin bowling

Tenpin bowling is a type of bowling in which a bowler rolls a bowling ball down a wood or synthetic lane toward ten pins positioned evenly in four rows in an equilateral triangle. The goal is to knock down all ten pins on the first delivery (a strike), or failing that, on the second delivery (a spare). While many people approach modern tenpin bowling simply as a recreational pastime, competitive bowlers consider it a demanding sport requiring precision and skill. The 41.5-inch-wide (105 cm), 60-foot-long (18 m) lane is bordered along its length by gutters (channels) that collect errant balls. The lane's long and narrow shape limits straight-line ball paths to angles that are shallower than the ideal entry angle(s) for achieving strikes. Accordingly, bowlers impart side rotation to hook (curve) the ball into the pins to increase the likelihood of striking. A 15-foot (5 m) long approach area is used by the bowler to impart speed and apply side rotation to the bowling ball, and is separated from the lane by a foul line. Crossing this foul line is detectable via sensors and results in a score of zero for the delivery in league or tournament play. Oil is applied to approximately the first two-thirds of the lane's length to allow a "skid" area for the ball before it encounters friction and hooks. The oil is applied in different lengths and layout patterns, especially in professional and tournament play, to add complexity and regulate challenge in the sport. When coupled with technological developments in bowling ball designs dating back to the early 1990s, easier oil patterns commonly used for league play have enabled many league bowlers to achieve scores rivaling those of professional bowlers who compete on more difficult patterns—a development that has caused substantial controversy. Tenpin bowling arose...