Why didn’t the Dallas Cowboys use more pre-snap motion?

Why?

Motions can tell you a lot pre-snap, but they tell you different things depending on whether you’re running or passing the ball.

Rushing the Ball

Cowboys fans are very aware of how poorly things go when the opposing offense runs a jet motion pre-snap. By paying attention to the motioning player, it can leave a gap exposed in the run fit allowing running backs to find open space once they get past the first level. Teams nowadays are better about dealing with motioning wide receivers forcing their cornerbacks to play more physical at the line of scrimmage, but the motion might still force the linebackers to adjust gaps depending on the strength of the formation.

For example, if the formation is showing a 2×2 (2 receivers to the left, 2 receivers to the right) set at the line of scrimmage, motioning someone from left to right forces the nickel cornerback to follow the receiver or force the linebackers to shift to the strong side of the formation to balance the space.

For offenses, a motion that can change the alignment of the linebackers/second-level defenders is integral for their play calling because it can decide two things: the direction of the run and the blocking assignments of the run.

Exhibit A:

If San Francisco lined up their running back, Jeff Wilson, on the left side and ran a Power to the right, they could have been reasonably successful even with the nickel defender in plain sight. However, by moving the tight end to the left, it allows the tight end and the left tackle to clear out the linebackers with little threat from secondary defenders at the line of scrimmage.

Exhibit B:

In this situation, Hasty motions to go set a block on the outside-most defender. In theory, if Hasty can clear space on the outside, Deebo Samuel can use his speed to ride the boundary instead of having to cut back. In this situation, the defensive back reads it correctly and forces Samuel to gain a tough five yards.

Another situation from the Cowboys this season was this big gain from Elliott, but it has little to do with the benefits of the motion. By motioning Jarwin out to the slot, it forces Jeremy Chinn to play the alley and the linebackers turn from stacking the defensive linemen to playing the A and B gaps. It makes it obvious for Tyron Smith to space block the B gap linebacker while Zack Martin needs to reach the A gap linebacker off his combo block. The motion did its job!

Unfortunately, the combo block never materializes correctly. When Elliott cuts inside anticipating the opening, the defensive lineman holds the double team and prevents any chance at a gain. Fortunately, brute force gets Elliott a nice gain.

These are just a few examples of motion in the run game, and while these haven’t been as successful as advertised, they should provide a good idea as to what it can do for the running game. Motions dictate blocking assignments and can manufacture space by attacking weak sides of defensive formations or individual personnel, but they don’t have as significant a pull in the running game as the layman might expect. If they did, the average team would be using pre-snap motion much more than 20 percent of the time.

Where a motion in the running game is perhaps most effective is when the motioning player is setting a block on someone at the line of scrimmage. It’s common for offensive coordinators to motion tight ends to the backside of the run to seal it in a split zone or have a wide receiver motion from the outside to crack/down block an edge defender allowing linemen to block in space.

From this last weekend, people are familiar with Kyle Shanahan himself motioning Trent Williams in the backfield only to set a wham block in the D gap on an unsuspecting lineman in order to prevent the defensive lineman from backdooring the front side of the outside zone toss.

If we’re throwing physics into the equation, it requires a lot of force to stop a large mass from moving at a certain velocity. I digress…

Passing the Ball

The reasons for motioning receivers in the passing game are endless. A motioning receiver could be the recipient of a screen pass giving a receiver already in motion the ability to accelerate quicker than defenders in the area. A motion with any receiver running directly behind another receiver could be used as a rub or pick generating instant separation at the line of scrimmage.

However, the most important use of motion in passing situations is to dictate whether the defense is play man or zone coverage based on their pre-snap look. If a defensive back is following a receiver, the expectation is the defense is playing man coverage. If the defense shifts in any capacity to the motioning side, the expectation is the defense is playing zone coverage.

This isn’t gospel as teams disguise coverages, but it doesn’t happen frequently enough for this to not be true because an undisciplined team trying to disguise coverage frequency leads to worse execution.

It’s from this point on, the offense is at the mercy of the defense. If the defense is showing man coverage, a pick off the line of scrimmage would likely generate separation. Contrastly against zone coverage, this pick doesn’t have the same result as defenders are responsible for space rather than a player.

A screen pass off a jet or orbit motion is likely more successful against cornerbacks lined up off instead of press as wide receivers have more time and momentum to block these defenders than against press coverage.

In summation, a motion has its place within the flow of the offense. The very fact that motions can help QBs decipher coverages makes it such an asset for offenses, but if the quarterback is already good at deciphering coverage pre-snap and the rest of the play is at the mercy of the defense, a motion doesn’t dictate too much in the end?

This leads me to…