a. A shift is a simultaneous change of position or stance by two or more offensive players after the ball is ready for play before the snap for a scrimmage down.
Approved Ruling 7-1-3 I. A21 is legally on the end of the line of scrimmage next to A88, who is in a three-point stance. Team A stops for one second while A21 and A88 are in the above positions, and then A21 moves to a legal backfield position and stops. Then A88 moves to a wider position on the line. RULING: Legal if both A21 and A88 are stationary at the snap (Rules 2-22-1 and 7-1-4).
Approved Ruling 7-1-3 II. A21 is legally on the end of the line of scrimmage next to A88, who is in the stance of a restricted lineman. Team A has stopped for one second when A21 leaves the line of scrimmage and goes in motion into the backfield. A88 moves to a wider position on the line. RULING: A88 may break his three-point stance since he is now on the end of the line of scrimmage, but Team A must stop again for one second before the snap to make the play legal (Rule 7-1-4).
Approved Ruling 7-1-2 I. After a huddle or shift, all Team A players come to a stop and remain stationary for one second. Then, before the snap, two or more simultaneously change their positions. RULING: All 11 Team A players must again stop for one second before the snap, otherwise it is a live-ball foul at the snap for an illegal shift. Penalty—Five yards from the previous spot (Rule 2-22-1).
Approved Ruling 7-1-2 II. Ten Team A players shift while A1 remains stationary. A1 then starts moving backward before one second elapses and the ball is snapped. RULING: If A1, who moved, did not halt with the other Team A players for one second before the snap, it is a dead-ball foul at the snap for a false start. Penalty—Five yards from the succeeding spot.
Approved Ruling 7-1-2 III. After the Team A players have stopped for one second, end A88 runs wide and stops, and before one second elapses, back A36 starts moving backward. RULING: Legal. But if back A36 starts before end A88 stops, the simultaneous movement of two players constitutes a shift, and all Team A players must be stationary for one second before the snap (Rule 2-22-1).
Approved Ruling 7-1-2 IV. Team A is in a no-huddle offense and is moving to the line when the ball is made ready for play. Although some players settle into their positions and stop, at least one player never stops and is still moving when the ball is snapped. RULING: Dead-ball foul: Illegal shift that converts to a false start. Team A never satisfied the one-second rule before the snap. Officials should shut the play down and penalize Team A five yards.
b. The shift ends when all players have been motionless for one full second.
c. The shift continues if one or more players are in motion before the end of the one second interval.