Running back

A running back (RB) is an American and Canadian football position, a member of the offensive backfield. The primary roles of a running back are to receive handoffs from the quarterback for a rushing play, to catch passes from out of the backfield, and to block. There are usually one or two running backs on the field for a given play, depending on the offensive formation. A running back may be a halfback (in certain contexts also referred to as a tailback) or a fullback.

Halfback/tailback

The halfback (HB) or tailback (TB) position is recognized as one of the more glamorous positions on the field, as it is often integral in both the passing and running attack. He is responsible for carrying the ball on the majority of running plays, and may frequently be used as a receiver on short passing plays. In today's game, an effective halfback must have a superior blend of both quickness and agility as a runner, as well as sure hands and shrewd vision upfield as a receiver. More and more quarterbacks depend on halfbacks as a safety valve receiver when primary targets downfield are covered or when they are under pressure. Occasionally, they line up as additional wide receivers. When not serving either of these functions, the primary responsibility of a halfback is to aid the offensive linemen in blocking, either to protect the quarterback or another player carrying the football. As a trick play, running backs are occasionally used to pass the ball on a halfback option play or halfback pass.

Offensive backfield

The offensive backfield is the area of an American football field behind the line of scrimmage. The offensive backfield can also refer to members of offense who begin plays behind the line, typically including any backs on the field, such as the quarterback, halfbacks, and/or fullback.

Play in the backfield

Most running plays begin with a hand-off in the offensive backfield. All kicks and punts must take place in the offensive backfield. If the offensive ball-carrier is tackled in the backfield, the team will lose yards, in that the distance they need to attain for a first down is more than at the beginning of the play.

Rules

There are many rules which differ for play in the offensive backfield as opposed to play in front of the line of scrimmage. The 1906 football rule reforms mandated that the offensive team line up with at least seven players on the line of scrimmage, which are now commonly called "lineman". Therefore, a spokesman maximum of four players are allowed in the offensive backfield. The other players not on the line of scrimmage may be positioned anywhere, but all must be at least 1 yard behind the seven or more players on the line of scrimmage. A forward pass can only be legally made from the offensive backfield.