American Football Field

Football games are played on a rectangular field that measures 120 yards (110 m) long and 53.33 yards (48.76 m) wide. Lines marked along the ends and sides of the field are known respectively as the end lines and side lines, and goal lines are marked 10 yards (9.1 m) inward from each end line. Weighted pylons are placed on the inside corner of the intersections of the goal lines and end lines.

Lines

Zones

White markings on the field identify the distance from the end zone. Inbound lines, or hash marks, are short parallel lines that mark off 1 yard (0.91 m) increments. Yard lines, which run the width of the field, are marked every 5 yards (4.6 m). A one yard wide is placed at each end of the field; this line is marked at the center of the two-yard line in professional play and at the three-yard line in college play. Numerals that display the distance from the closest goal line in multiples of ten are placed on both sides of the field every ten yards.

Goalposts are located at the center of the plane of each of the two end lines. The crossbar of these posts is ten feet (3 meters) above the ground, with vertical uprights at the end of the crossbar 18 feet 6 inches (6 m) apart for professional and collegiate play and 23 feet 4 inches (7 m) apart for high school play. The uprights extend vertically 35 feet on professional fields, a minimum of 10 yards on college fields, and a minimum of ten feet on high school fields. Goal posts are padded at the base, and orange ribbons are normally placed at the tip of each upright.

The football itself is an oval ball, similar to the balls used in rugby or Australian rules football. At all levels of play, the football is inflated to 12 1⁄2 to 13 1⁄2 pounds per square inch (psi) and weighs 14 to 15 ounces (397 to 425 grams); beyond that, the exact dimensions vary slightly. In professional play the ball has a long axis of 11 to 11 1⁄4 inches, a long circumference of 28 to 28 1⁄2 inches, and a short circumference of 21 to 21 1⁄4 inches, while in college and high school play the ball has a long axis of 10 7⁄8 to 11 7⁄16 inches, a long circumference of 27 3⁄4 to 28 1⁄2 inches, and a short circumference of 20 3⁄4 to 21 1⁄4 inches.

SPORTS

American Football

Game play in American football consists of a series of downs, individual plays of short duration, outside of which the ball is dead or not in play. These can be plays from scrimmage – passes, runs, punts, or field goal attempts (from either a place kick or a drop kick) – or free kicks such as kickoffs and fair catch kicks. Substitutions can be made between downs, which allows for a great deal of specialization as coaches choose the players best suited for each particular situation. During a play, each team should have no more than 11 players on the field, and each of them has specific tasks assigned for that specific play.