Running backs are players who line up behind the offensive line, in the position to receive the ball from the quarterback and execute a rushing play. Anywhere from one to three running backs may be utilized on a play (or even none, a situation typically known as an "empty backfield"). Depending on where they line up, and what role they have, running backs come in several varieties. The "tailback" (or sometimes the "halfback") is often a team's primary ball carrier on rushing plays. They may also catch passes, often acting as a "check-down" or "safety valve" when all other receivers on a pass play are covered. The "fullback" is often larger and stronger than the tailback, and acts primarily as a blocker, though the fullback may also be used for catching passes or for rushing as a tailback does. Fullbacks often line up closer to the line of scrimmage than tailbacks do, so they may block for them. A "wing-back" or a "slot-back" is a term for a running back who lines up behind the line of scrimmage outside the tackle or tight end on the side where positioned. Slot-backs are usually only found in certain offensive alignments, such as the flexbone formation. A similar position, known as the H-back, is actually considered a modification of the normal tight end position (see below).
|