Dallas Cowboys Bigger Priority: Fixing Run-D or Improving Secondary?

2020 was a failure on all fronts for the Dallas Cowboys defense. Offenses ran against Dallas to the tune of 5.0 yards/carry and 158.8 yards/game. Through the air they passed for 7.4 yard/attempt and 227.6 per game, The 31st ranked run defense and the 11th ranked pass defense combined to give the Cowboys a 22nd ranking overall (based on traditional y/g).

So it really goes without saying, it’s important for the Dallas Cowboys to fix both aspects of their defense this offseason. It’s awfully hard to win a game, let alone go on a postseason run, running out a bottom-10 defense every week.  In other words, Team 40-Burger ain’t much good if your defense is Team 41-Burger. Am I right?

But what defensive area specifically should the Dallas Cowboys prioritize? Is the 31st ranked run-D the bigger issue or is it the 11th ranked pass defense that should be top priority? Let’s look at some key numbers and try to determine. The answer might surprise you…

The Dallas Cowboys’ secondary hurt them far more than their horrific run defense

As the above line bluntly states, the Cowboys secondary deserves the most attention and should be the bigger priority this offseason. Whether it’s through free agency or the NFL Draft, Dallas will need to invest more time and resources to stop the pass than to stop the run And it’s not just because two starters, Chidobe Awuzie and Xavier Woods, are set to leave. It’s because Dallas was hurt more against the pass than they were against the run last season.

Despite what the overall league rankings indicate, the Dallas Cowboys were worse against the pass than they were against the run last season. For as back-breaking as those 5+ yard runs were game after game last season, the damage was far less than the plays made through the air against Dallas.

Let’s add some value to the raw numbers. 5.0 y/c doesn’t mean much if we don’t have context, right? A 5.5 yard run sounds bad but if it’s on 3rd-and-6, it’s actually a win for the defense. A 20-yard pass completion allowed sounds like bad thing, but if it happened when time expired in the first half, it’s a win for the defense.

Looking at expected points added (EPA) and success rates, we can see how often opponents had success against Dallas, and to what extent. The scores are in context so we have the ability to replace what we “feel” with what we “know.” Always the goal in enlightened sports analysis.

In a nutshell, by using historical data from the past decade plus, expected points added looks at the points expected from a certain down and distance before the play, recalculates after the play, and appraises the value of said play. As such, a 2-yard run on 4th-and-1 at midfield would be worth more than an 8-yard run on 4th-and-10 at midfield. The first play would extend the drive and increase scoring chances while the second play would kill scoring chances and result in a negative EPA score. Yards don’t matter as much as context.

Success rate is similar. Simply put, if a team increased their scoring chance (+EPA) then the play was a success. If they didn’t increase their scoring chance, the play was unsuccessful. That’s why a 3-yard run on 1st-and 10 is an unsuccessful play and a 2-yard run on 3rd-and-2 is a successful play. One play helps the team and the other hurts the team (1st-and-10 is better than 2nd-and-7 every day of the week).

Last season the Dallas Cowboys gave up runs at a clip of 5.0 ypc but only 44.5 percent of them were successful runs by the opposing offense. That means more often than not, Dallas won the running game battle on defense. Against the pass we saw opposing offenses achieve a success rate of 51.7 percent against the Dallas D. So more often than not, opposing passing offenses beat the Dallas D (as per rbsdm.com with win probability between 30-70%).

Since not all successes are created equal, let’s look at the EPA of these plays so we can appraise the value. As a whole, the Dallas D gave up and average EPA of -0.015 on the ground. You’ll notice that number is negative, meaning as a whole, offenses hurt their scoring chances running the ball against Dallas. If you’re anything like me this is in direct conflict to how I “felt” last season (which is why these numbers are so important).

Through the air, the Dallas D gave up an average EPA of 0.204. That’s a positive number so combined with the higher success rate against, it clearly wins the crown as the weakest link of the Cowboys defense.

Flashbacks of opponents running at will not withstanding, this shouldn’t come as a surprise. League wide, only six teams gave up a positive EPA on the ground. And we know from previous studies, the winner of the passing game has a bigger impact on the game than the winner of the rushing battle. That’s not to say a running game can’t dominate a contest and be the deciding factor, it just means more often than not, it’s the passing game that makes the difference.

It’s also worth pointing out, while only nine run defenses were worse than Dallas’ last season (in success rate), three of those were division winners. Green Bay and Kansas City were also worse in run EPA against. That tells us it’s certainly not a death knell to have a porous run D. It’s frustrating and should be avoided, but it’s nowhere near as important as some are making it out to be. And its importance pales in comparison to pass defense. Of the eight teams who were worse than Dallas against the pass, only one made the postseason.

The Dallas run-D also improved down the stretch. Over the second half of the season, Dallas’ rush EPA against, improved to -0.061 (pushing them into the top-20). Again, not ideal, but certainly some reason for optimism.

Dallas needs to improve their run D, there’s no question. But playing more single high safety (which moves an extra man in the box) should work wonders by itself. It’s the passing game that did the most damage to Dallas last year and if the Cowboys played in more close games, we’d see that reflect in the cumulative stats so may people lean on for their decision making.

Factor in the turnover in personnel this offseason, and the secondary should probably be Priority 1 and Priority 2 this offseason.

The Dallas Cowboys need to devote most of their attention to fixing the secondary. Opposing offenses inflicted far more damage through the air than they did on the ground and it’s important to keep that in mind while we prioritize offseason tasks.