Could the Loss of DeMarco Murray Hurt the Cowboys' Defense in 2015?

It’s no secret the Dallas Cowboys were a run heavy team last season.

They weren’t technically a “run first” team -- the Cowboys dropped back one more time than they ran the ball in 2014 (still a 1.00 pass to run ratio), but they were the third most run heavy team in the league.

At this point, there’s little use in going over how much DeMarco Murray meant to the offense, but the loss of Murray could have just as much of an impact on the other side of the ball. That could be a major problem for the Cowboys in 2015.

Ball Control

In 2014, Murray lined up for exactly zero snaps on the defensive side of the ball but might have been its most meaningful player.

On a per-game basis, time of possession can be a widely overblown statistic. Announcers will talk about it all the time as a key to the game, but it doesn’t always equate to offensive success. Take the San Francisco 49ers, for example. They ranked seventh among all NFL teams in time of possession last season. It’s hard to imagine anyone looking at the 2014 49ers offense as a model of success. But with a competent run game and efficient passing offense that is able to repeat this type of strategy on a week-to-week basis, this type of play can be an effective way to game plan.

That’s exactly what the Cowboys did last season. Dallas was one of the more efficient running teams in the league but not the best as many would assume. By our Net Expected Points metric (NEP), which factors in on-field variables such as down-and-distance in order to compare a team or player’s production to historical expectation levels, the Cowboys had the ninth best rushing offense on a per-attempt basis while adjusting for opponents.

When an offense can be that efficient with that much volume -- the Cowboys had the fourth most rushing attempts overall last season -- it can be tough for any defense to stop. Dallas also had the second best Adjusted Passing NEP per play last season, which gave the team the ability to do just about whatever they wanted on offense at any time. Not a bad ability to have.

Dallas’ productivity on offense understandably led to a lot of points, which in turn led to a lot of leads. That allowed the Cowboys to slow the pace of their offense down to a glacial speed. According to pace stats compiled by Jim Armstrong at Football Outsiders, no team took more time between plays than the Cowboys at 30.12 seconds per play, and no other team in the NFL was above 30 seconds. The pace statistics also break down to game situations by score, splitting up the pace to whether the offense had the lead or trailed.

In none of the different pace stats did Dallas rank higher than 28th. Overall, that allowed the Cowboys to hold the highest average time of possession in the league last season.

Hiding the Defense

While the offense was able to hold the ball for extended periods of time and turn those possessions into points -- Dallas ranked second in points per drive -- an intended consequence was to keep a defensive that wasn’t very good off the field. The Cowboys were just in the middle of the pack by giving up points, 15th in league, but they were a bottom third defense according to Adjusted Defensive NEP, ranking 24th on a per play basis.

Only three teams faced fewer defense plays than the Cowboys last season. It should be noted two of them, the Steelers and Jets, did rank worse than the Cowboys in Adjusted Defensive NEP per play. The other was the Seahawks. The Jets tried to fix that problem by hiring Todd Bowles as their new head coach, and while the Steelers will be without Le'Veon Bell to start the season, it’s more likely they could follow a similar game plan with Bell and Ben Roethlisberger leading the offense throughout most of the year.

In 2014, the Dallas defense gave up more yards per drive than all but five defenses but were bailed out by turnovers. The Cowboys led the league in defensive turnovers per drive, which was due in part to the third best fumble recovery rate on defense. Dallas recovered 59.26 percent of 20 defensive fumbles last year, tied with Philadelphia and behind just Jacksonville and Atlanta.

Fumble recovery is typically a 50-50 proposition from year-to-year, so the Dallas defense should not be expected to fall on the ball at such a high rate in the future. The Cowboys also tied for seventh in interceptions with 18, but that wasn’t due to stellar secondary play (they ranked 23rd in Adjusted Defensive Passing NEP per play). Rather, inside linebacker Bruce Carter led the defense with five picks after having none in his first three seasons, and he will be suiting up for the Tampa Bay Buccaneers in 2015. A reliance on turnovers can help some teams, but it’s a tricky thing to sustain.

Without turnovers, and with the potential for more time on the field, the Dallas defense is likely to see a few more drives end in points. While the Cowboys were 16th in points allowed per drive, they allowed the sixth most touchdowns per drive of any defense.

Future Impact

To their credit, the Cowboys didn’t just look at the 2014 defense, think it was adequate, and let it be.

There were a few additions that could help the squad improve this coming season. Sean Lee will be back, though it will be unclear how much he will be able to play like his former self, and the Cowboys brought in two potential forces for the pass rush in Greg Hardy and Randy Gregory. Yes this gives them better personnel than last season, but it will remain to be seen what impact it could have if the defense still needs to be on the field significantly more than it was last season.

No one is expecting the Dallas defense to be one of the better defensive units in the league suddenly, but there could still be a few who watched the defense in 2014 and saw something they thought resembled the league average. The Cowboys did a great job of hiding the defense last season, better than any other team in the league. But with a still-yet-to-be determined group of Joseph Randle, Lance Dunbar, Darren McFadden and others stepping in for DeMarco Murray, the luxury of a slow-paced run game that was so successful last season might not be an option.

That, in turn, could lead to more points scored by opponents, which might force the Cowboys to play in some closer games and throw more passes. It might be a chicken and the egg situation, but regardless of the starting point, it could be something that affects Dallas this season.

The Cowboys weren’t a good defense by our metrics last year, but they got by. They might not be put in the same position again this season.