Fixing the Dallas Cowboys offense: Beating shells coverage

In 2021, the Dallas Cowboys started off one of the best offenses in the NFL. They were fourth in the NFL in expected points added (EPA) per play, second in overall success rate, third in EPA per drop back, and first in drop back (passing) success rate.

Then the bye week happened and everything seemed to change. Borrowing a page from the Vic Fangio playbook, NFL defenses started combatting high-powered passing offenses with a coverage-heavy shell scheme. It smothered offenses and gave aggressive offensive coordinators fits.

An evolution from the Cover-2 of yesteryear, and a departure from the Seattle single-high fad of most recent, defenses focused on packing the secondary and daring offenses to either throw into coverage or settle for peanuts.

Coverage-heavy defenses gave the Dallas Cowboys fits last season, do the Cowboys have what it takes to overcome?

The strategy was first tried out against Dallas in Week 2 by the LA Chargers. Brandon Staley, the top defensive mastermind now leading the trend, dared the Dallas Cowboys to run the ball (specifically on early downs) by showing a light box and packing the secondary.

Using a mix of Cover 2, 3, and 6, he played shells over the top, cut off the crossers the Dallas Cowboys often lean on (most top offenses use them) and forced Dallas to throw unattractive shallow balls short of the sticks or low percentage deep balls down the sideline.

The end result of this was a Cowboys win, but it took exceptional effort from the running game to make it happen. Dak Prescott conceded much of the aerial attack and settled for a 5.1 average depth of target, finishing the day with a -0.01 EPA/play (virtually unheard of for Dak).

Meanwhile, Ezekiel Elliott and Tony Pollard feasted, logging a 0.25 EPA/play and 61% success rate (unheard of in a positive way) enroute to a 198 yard rushing day for the Dallas duo.

Staley’s defense took away everything over the top and forced runs or short passes. His ultra-aggressive secondary is designed to give up short passes/dump-offs/screens and collapse into the “killzone” stopping any potential yards after the catch (YAC) in an instant.

They kept the game close throughout and if not for a abnormally dominant effort by the Cowboys running game, might have beat an otherwise more talented Dallas squad.

The NFL took notice

This blueprint did not go unseen by NFL defensive coordinators. All year teams would successfully use this method on dominant offenses like the Dallas Cowboys, Tampa Bay Buccaneers, and Kansas City Chiefs. It had been picking up steam for the past few seasons and last year hit its peak usage.

Cover-2? Cover-3? Cover-4? Quarters? Contrary to popular belief, Staley-like teams changed between them often, sometimes employing one thing on the strong side and a different coverage on the weakside, what stayed the same was safety shells and the collapsing secondary.

After the Dallas Cowboys bye week, it became the go-to blueprint to stop the Dallas offense. The difference was, after the bye week, Dallas couldn’t run the ball well enough to make the defense pay.

Beating NFL Trends

As mentioned earlier, this defensive strategy isn’t unique for the Dallas Cowboys. It’s a defensive philosophy that’s deployed against nearly all the NFL’s top offenses. It’s designed to take away what offenses want (crossing routes, middle of the field, deep passes) and gives them what they don’t want (early down runs, short passes into the kill zone, low percentage sideline targets).

It’s particularly effective in the way it disguises its intentions. It looks one way before the snap and shifts to something completely different after the snap. The Dallas Cowboys struggled immensely with this element of deceit.

All too often the Cowboys went to the line with what they though was the perfect call, only to fall right into the defense’s trap. With little to no time in the pocket, Dak Prescott could do little to adjust mid-play. Rinse and repeat all season long.

What can the Dallas Cowboys do? For one, Kellen Moore and Dak Prescott have to be prepared for this each and every game. Decades ago Mike Martz and Norv Turner designed their offenses to beat many of these same looks. It’s time to pull solutions from the past.

Coverage-heavy shells worked last season and you can bet teams are going to see if it will work again this season. Even if it looks like that old Cover 1 before the snap, does not mean it’s going to be that when the ball moves. Better diagnosis and failsafe’s need to be built into the game plan.

Note: Shells isn’t just a Cover-2 philosophy. Teams used Cover 3, 4, and 6 with shells as well.

Even more importantly, the Dallas Cowboys need their offensive line to improve. From Week 9 on, the Dallas offensive line was nothing short of atrocious. It’s a period of time in which Tyron Smith missed more games than he played and nearly every spot along the line underachieved.

The running game didn’t have holes to run through nor could they consistently break tackles. Yards per rushing attempt dropped from 5.1 yards (4th in the NFL) to 3.5 yards (21st). And the passing game didn’t do much better. Dak’s completion percentage dropped eight percent and his yards per attempt dropped to 6.6 (18th in the NFL).

Prescott’s 2.75 second average time in the pocket still ranked him the 12th fastest passer, but you’d never know it because he was pressured at a much higher rate – despite the blitz rate dropping from 37% to 24% after the bye. Defensive front-fours were having their way with the Dallas O-line and Dak’s sack rate almost doubled. That’s against all logic and an indictment on the O-line.

If the Dallas Cowboys can just fix their front-five deficiencies, they’ll be in much better shape to succeed. Much like what happened against the Chargers in Week 2.

The Dallas Cowboys had all offseason to overcome this challenge. They invested their first pick in the offensive line and seem to be betting big on Tyron Smith’s health. If the offensive line works out, the Cowboys should be well-equipped for any kind of shells defense that gets thrown at them. If not, it doesn’t matter what Kellen Moore does to game plan or how good Dak gets at recognizing the trickery. They need that O-line to hold up.

The NFL is cyclical and this obviously isn’t the first time shell coverages have been used to take away the strengths of a dominant offense. But the Air Coryell offense was designed to beat this very thing and Kellen Moore is well versed in the concepts of Jason Garrett’s system (yeah, I know. It hurt me to point that out) so he comes fully equipped with troubleshooting solutions.

What beat the Dallas Cowboys offense last season? Coverage heavy looks that relied on the front-4 to get pressure and stop the run. If the Cowboys can rediscover their dominance on the O-line and employ some of the Air Coryell concepts designed to break Cover 2 concepts of the like, then Dallas should be in good shape this season.