What Is an Illegal Shift in Football? The Ultimate Guide


Offensive and defensive linemen get ready for the snap.

There are over 40 penalties in football, one of which is an illegal shift, which can be confusing and easy to miss. Illegal shifts can be very costly to a team but before we get too ahead of ourselves we need to find out what an illegal shift in football is and when it happens.

So, what is an illegal shift in football?

An illegal shift is a 5yd penalty that occurs when two or more players on the offense move simultaneously before the play starts. The penalty states that after the formation is set, only one player is allowed movement. This rule gives the defense a chance to set up and make adjustments if needed.

This penalty can be confused with other penalties (which we’ll get to later) so it’s important to remember that illegal shifts occur before the ball is snapped. Illegal shift penalties have changed the momentum and outcome of many football games as we will see below so it’s important for coaches and players to understand the rule.

What Is an Illegal Shift?

As mentioned, an illegal shift is when multiple players move at the same time before the ball is snapped. This penalty is often difficult to spot when watching a game because the rule specifies that all players must be completely still for one full second before another player can move.

The referees look for even the smallest movement which is why when you’re watching a game and see the yellow flag flying, it can be confusing as to why it was a penalty until you see the slow-motion replay.

The movement refs look for can be as subtle as a lineman taking one step back while a receiver is in motion or a player trying to re-set their feet before the snap. It seems like a picky rule, but it ensures that all players are set for at least one full second before the ball is snapped. An interesting fact about this penalty is that it isn’t considered a penalty in the AFL (American Football League) or the CFL (Canadian Football League).

How to Prevent Illegal Shifts

Since this penalty mainly occurs when the offense is trying to get off a quick play, one of the best ways to prevent this penalty is through time management. This preventative method goes beyond the field and requires all coaches and coordinators to be in tune with what’s happening.

All players need to be aware of the play clock and where they’re on the field. Getting off a quick play before the defense is set can be a way for the offense to get a leg up, but it shouldn’t be rushed to the point of making a mistake such as an illegal shift.

Even the slightest step out of turn while trying to rush a play can result in an illegal shift and it isn’t worth the extra two seconds they may have on the defense.

Another possible way to prevent this penalty is by calling the play in the huddle (and sticking to it). This, however, is not always possible. Even the best offensive teams and coordinators have to scramble sometimes, which means a play may be called out after the huddle.

If the defense suddenly makes changes at their line of scrimmage and the offensive coordinator/quarterback wants to change the play, it must be understood by all offensive players to be successful.

If every player doesn’t hear the audible after they leave the huddle, there might be extra movement resulting in an illegal shift. The best way to prevent an illegal shift from happening is by staying away from play changes outside of the huddle.

How Often Do Illegal Shifts Happen?

Illegal shift penalties are fairly common. They’re certainly not one of the top five offensive penalties, but they occur quite commonly in fast-paced situations. When a game is close in score (especially in the third or fourth quarters), the offense is going to try to get a leg-up on the defense.

Of the 47 different penalties given in the 2021 season, illegal shifts ranked 22nd on the penalty count list.

One way to get an advantage is to have no-huddle plays, which can be effective if done correctly, but destructive if everyone isn’t on the same page. The best professional and high-ranking college football teams usually avoid illegal shifts because each player has the plays and their role memorized.

Illegal Shift Signal

The signal referees use for an illegal shift begins with two hands together (knuckles touching) at their chest, with their elbows bent. They then extend their arms out to the sides forming a ‘T’, before bringing their hands back to their chest. They will repeat this motion once or twice.

The signal for an illegal shift can be confused with one for an incomplete pass, but a referee won’t cross their arms at any point when signaling an illegal shift. Also, if there’s no flag on the ground, it’s a safe bet the call is for an incomplete pass and not an illegal shift.

Illegal Shift Penalty

The offensive linemen and quarterback get ready for the snap.

The penalty for an illegal shift is a loss of five yards and a replay of the current down. This might not seem like much, but you should take into consideration that the penalty also results in time lost on the play clock. An illegal shift in the fourth quarter can have a huge impact on who wins the game.

Illegal Shift Examples

While countless illegal shift penalties have been called throughout the years, there have been some notable instances where the penalty changed the course of the game.

Oct. 12, 2019 (UGA vs South Carolina): This was a close game and in the fourth quarter with 13 seconds left on the clock, Georgia ran a play that ended up getting flagged as an illegal shift. This of course cost them five yards, the replay of down, and most importantly, 10 seconds off the play clock. This left them with only 3 seconds on the clock, which ultimately led to the game going into overtime.

Jan. 10, 2016 (Packers vs Redskins): Late in the second quarter, the Packers had a beautiful play with an easy touchdown pass to end the first half. However, another play was called at the line of scrimmage, which led to multiple players moving at once. This should have been flagged as an illegal shift but was overlooked, causing a bit of controversy at the time. This touchdown not being flagged changed the momentum of the game.

September 15th, 2013 (Colts vs Dolphins): The Colts, who had Andrew Luck as their quarterback at the time, had a beautiful play resulting in what the whole stadium believed to be a touchdown. There was of course some confusion when the yellow flag made its appearance. The referee cited the full second requirement, stating that more than one player moved simultaneously. This resulted in the touchdown being brought back and a loss of five yards.

Illegal Shift vs False Start

An illegal shift penalty can easily be confused with a false start penalty. The key difference is a false start penalty occurs when a player makes a post-snap move before the ball has been snapped. (I.E. When a lineman gets in a blocking position before or crosses the line of scrimmage before the snap)

This is a much more common penalty and is actually one of the only penalties that the defense will purposely try to bring about from the offense. It’s not uncommon to see players on the defensive line pointing out when an offensive player commits a false start penalty.

While the false start penalty is a certain movement (post-snap movement) that occurs before the snap, illegal shifts most commonly occur when there are two or more players in motion at the same time before the snap.

These two can be confused, but it helps to remember that an illegal shift is typically going to occur with two or more moving players whereas a false start happens with just one player.

Illegal Shift vs Illegal Motion

Another penalty that can be confused with an illegal shift is illegal motion. There are key differences here as well. An illegal motion penalty occurs when a player is moving at the time of the snap.

This seems like an insignificant distinction, but it’s a very important one. A motion at the time of the snap is a player moving at the exact same time that the ball is being snapped from the center.

There should be no motion on the line of scrimmage at that exact moment the ball is snapped, so when a player moves during that time, it’s considered an illegal motion. An illegal shift, however, can occur before the ball is snapped.

An illegal shift is motion that occurs while the players are still getting set on the line of scrimmage. Again, we’re looking for two or more players in motion here as the main distinguishing factor and this typically happens during a rushed play, which occurs before the ball is snapped.

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Steven G.

My name is Steven and I love everything sports! I created this website to share my passion with all of you. Enjoy!

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