A sweep in football is a rushing play in which the running back, who is lined up next the quarterback while in the backfield, is given the ball and then rushes parallel to the line of scrimmage in either direction to the line towards the sideline. The ball can also be pitched to the running back while running in either direction. The play gets the name from the sweeping arch the running back makes while running the route of the play. It is a fairly common play in most playbooks, but is most closely associated with the spread offense.
A sweep may also refer to a series sweep, in which a team wins all the games against an opponent over the course of a series or season. In football, Division opponents play one-another twice per season. If one team were to win both of the games during the season, it is said that they "swept the series" against the other team. This is also a term used in baseball.
There are variations of the sweep play that can be run. Popular variants include: the pitch sweep, the jet sweep, and the fly sweep.
The pitch sweep is probably the second most common play of the sweep playbook. This particular play involves the quarterback behind the center and the running back in the backfield. The running back still runs in the sweeping motion, however, he receives the ball via pitch from the quarterback.
The jet sweep and fly sweep are very risky plays as they usually involve a wide receiver carrying the ball rather than the running back. In these sets, the quarterback stands in the shotgun formation with the running back beside them. A third player, either a fullback or wide receiver, will rush parallel to the line of scrimmage and receive the ball from the quarterback after the snap, and continue rushing. These plays are very risky and can lead to big losses.