The American-style football is normally 11 inches (28 centimeters) long, with a circumference of 22 inches (56 centimeters) at the center. Although once made with the flesh of a pig's bladder (thus the nickname "pigskin"), modern footballs are made of leather, although cheaper footballs for recreational use may be found made of rubber or plastic. The leather is usually tanned to a brown color, especially for use in professional and collegiate play, and stamped with a pebble-grain texture to improve the ability to grip the ball.
At the top of the ball is a white grip comprised of seven small vertical strips holding a larger horizontal strip, designed to help improve holding grip, especially when passing the ball.
In a game, the ball may be moved in one of three ways: running, passing (if the throwing player is behind the line of scrimmage), or kicking the ball in a field goal attempt or punt to the opposing team. It should be noted that the forward pass was only introduced to the game in 1906, the result of political pressure in the face of an alarming number of injuries in the years prior. While it took a while for the forward pass to become a part of the game, it would eventually become the dominant play style in professional American Football.