Cowboys Film Study: Motion Statistics
NFL teams use motion for a variety of reasons: to uncover defensive coverages, to get defenders out of position, to exploit positive match-ups, and so on. The frequency of motions also differs greatly among teams. Some, like the Bengals, like to motion very frequently. Others, such as Peyton Manning’s Colts, almost never motion.
We analyzed our film database to determine just how many plays the Cowboys motioned in 2010 and exactly how effective those plays turned out. The results, shown below, were a bit surprising.
As you can see, the Cowboys tend to run the ball at higher rate after motions than on plays where there is no pre-snap movement (46.4 percent runs after motion versus 36.2 percent non-motion).
However, this is not necessarily a knock on Jason Garrett, as the Cowboys frequently remain static pre-snap in situations where the defense knows they are going to pass.
For example, when the Cowboys lined up in “Gun TE Spread” (shown to the right), a formation that they threw out of 83.3 percent of all plays, the offense motioned only 12.5 percent of the time (as compared to a 42.8 percent motion rate on all plays). Thus, while the run/pass ratio after motions is a bit skewed, it creates no real competitive advantage for the defense.
More significant than the rate at which Dallas runs or passes after motioning is the efficiency (or lack thereof) of the post-motion plays. As you can see, the Cowboys gained significantly less yards-per-play on both runs and passes after motions (.7 yards less on passes and a full yard less on runs).
Why is this the case? Are the Cowboys simply less effective on offense when they motion?
It is tough to say, but our initial thought was that the the drop in yards-per-play was caused by a possible tendency to motion on short-yardage plays. Thus, the upside would be limited and the averages would suffer.
However, on short-yardage plays (three yards to go or less), the Cowboys motioned just 44.8 percent of the time–barely more than the 42.5 percent overall rate. Thus, while it is good that Garrett effectively spreads out motions among various downs and distances, the low yards-per-play on motions cannot be attributed to an abundance of short-yardage plays.
Another possible explanation is that, because the Cowboys rarely motion in their hurry-up offense, the yards-per-play might be greater on non-motion plays because defenses are more likely to play soft and give up yardage.
However, this could only explain the difference in passing average between motion and non-motion plays, as teams rarely run the ball in hurry-up scenarios.
Further, the Cowboys actually only ran a true hurry-up offense just 80 times in 2009, or just 8.0 percent of all plays. Thus, it appears that the Cowboys success when not motioning is actually due to something meaningful rather than just down and distance or game situation.
This notion is strengthened by both the rate of big plays garnered and negative plays yielded in motion and non-motion situations. As the chart shows, the Cowboys had their highest rate of big plays (10+ yards) out of static formations.
While this statistic could be affected by the aforementioned tendency of Dallas to not motion in hurry-up situations, the most surprising and meaningful statistic, in our opinion, is the rate of negative plays given up in each scenario. The Cowboys actually gave up a sack after motions at nearly 2.4 times the rate they yielded a sack on non-motion plays. Our sample size of both types of plays makes that number statistically significant.
Further, the rate of overall negative plays (sacks, negative runs, and negative passes) was nearly twice as high on plays where the Cowboys moved a player pre-snap.
But why is this the case? Why do the Cowboys have a larger downside without an increased upside on plays that they motion, despite not running these plays in “low upside” situations?
For us, the answer is not entirely clear. Perhaps Tony Romo is just much better at reading defenses than anyone thought. Maybe motions give him no advantage in reading coverage. We don’t want to put him on the same level as a Peyton Manning just yet, but perhaps he is approaching a portion of his career where, like Manning, he can effectively read a defense without resorting to pre-snap motions.
Another reason might be that the Cowboys’ motions are giving the defense an idea of where the play is going to be run. After watching as much film as we do, there are times when we can predict with great precision what play the Cowboys are going to run. How and where they motion is a big factor in our ability to do this.
This last explanation would explain the significant gap between motion and non-motion run average, as it is easier for a defense to decipher a particular run play from a motion than a pass.
The Cowboys are quite obviously less effective on plays which involve a pre-snap motion. Further, the reason for this does not seem to be due to particular game situations.
So where should the Cowboys go from here? Should they scrap motioning completely and resort to an Indianapolis-esque offense?
Like our solution to many of Dallas’ woes, we believe the “Nash equilibrium” should be implemented. Again, this is the point where the Cowboys’ total yards would be maximized.
Thus, Garrett should steadily decrease the motion rate until the defense compensates enough that the Cowboys’ yards-per-play reaches its peak. Our guess is that this is around 25.0 percent. At this point, it is likely the rate of big plays and negative plays will also be maximized and minimized, respectively.