Shift (gridiron football)

There is a distinction drawn between a shift and motion in football. Motion occurs when a player is moving at the time of the snap. A shift occurs when one or more players changes their position on the offensive side of the ball before the snap, causing a change in formation. For example, players may line up initially in an I-formation and then shift the two running backs into wide receiver positions to put the offense in a spread formation. A team may shift any number of players into new positions, so long as they all come to a complete stop for a full second before the ball is snapped to start the play.

The National Football League (NFL) defines all motion and shift penalties as "illegal motion",^[1] while both the NCAA and NFHSAA make a distinction between an "illegal shift" and "illegal motion"; an illegal shift refers to players shifting and not coming to a complete stop before the snap, while illegal motion refers to a player who is in motion towards the line of scrimmage, or a player who is not a "back" in motion.^[2] In both leagues, however, the penalty for illegal motion/illegal shift is five yards from the previous spot and replay the down.

Additionally, the offensive team may be charged with the penalty of a "false start" if a player on the offense jumps or moves abruptly, simulating the start of the play. This movement is not normally considered a subset of the "motion" or "shift" rules, as the player is not judged to be moving into a new pre-snap position; they are merely starting the play too soon. This is also a five yard penalty.

Both motions and shift were introduced by Amos Alonzo Stagg.^[3] The history of college football involves three notable, distinct shifts:

• The Minnesota shift, used by the likes of Henry L. Williams.
• The Jump shift or Heisman shift, used by the likes of John Heisman.
• The Notre Dame Box, used by the likes of Knute Rockne.