Last year's Dallas Cowboys finished a disappointing 8-8. While the offense was the subject of much consternation throughout the season, it was actually the defense that was the team's weaker unit. Dallas finished the year first in yards, sixth in points, and second in Football Outsiders' DVOA on offense, but just ninth in yards, 22nd in points, and 21st in DVOA on defense. 

The Cowboys struggled to force turnovers, finishing 31st in the league in interception rate. They struggled to create pressure, finishing a benign 16th in pressure rate, 20th in quarterback hits, and 19th in Adjusted Sack Rate. They were only 16th in tackles for loss and 18th in stuff rate, stopping only 18 percent of opponent categories at or behind the line of scrimmage. As a result, they ranked 15th against the run and 23rd against the pass, according to DVOA. 

While the team's splashiest changes came in the coaching ranks (swapping Jason Garrett for Mike McCarthy) and on offense (letting Jason Witten and Randall Cobb walk, promoting Blake Jarwin and drafting CeeDee Lamb), the team underwent significantly more turnover on the defensive side of the ball. No. 1 cornerback Byron Jones left in free agency, and he wasn't the only one. Defensive linemen Robert Quinn, Maliek Collins, Kerry Hyder, and Christian Covington signed elsewhere, as did safeties Jeff Heath and Kavon Frazier, and cornerback Donovan Olumba. Michael Bennett retired. Linebacker Malcolm Smith remains unsigned.

The Cowboys brought in a whole lot of new players to replace them. Ha Ha Clinton-Dix was brought in at safety. Trevon Diggs and Reggie Robinson were drafted as corners, plus the team signed Daryl Worley. But nowhere have there been more changes than up front. Losing five defensive linemen will tend to do that. To replace Quinn, Collins, Hyder, and Covington, the Cowboys first signed Gerald McCoy, Dontari Poe, and Aldon Smith, then drafted Neville Gallimore and Bradlee Anae. Earlier this week, they signed former Vikings Pro Bowler Everson Griffen, and on Friday, they activated Tyrone Crawford from the Physically Unable to Perform List. 

Dallas gave 11 defensive linemen snaps last year, and right now, the Cowboys have 12 options for those 11 spots: McCoy, Poe, Smith, Gallimore, Anae, Griffen, and Crawford, plus Demarcus Lawrence, Dorance Armstrong, Joe Jackson, Antwaun Woods, and Trysten Hill

We know Lawrence is going to man his usual spot at left defensive end, and likely play a ton of snaps. McCoy will be the 3-technique tackle. Poe will play 1-tech, with Woods likely filling in behind him. Crawford, who played only 90 snaps last season due to injuries, brings an element of versatility the team badly missed a year ago. He prefers to play on the edge (and seems like a likely starter across from Lawrence), but has often been at his best as a penetrating interior lineman. If and when he bumps inside, the Cowboys have a ton of options for the other edge spot in Griffen (eight sacks last year, 57 in the past six seasons) and Smith (12.9 sacks per 16 games average for his career, though he has not played in five years), plus Armstrong, Jackson, and Anae. Hill, the 2019 second-rounder, was not drafted by this coaching staff so he is probably behind Gallimore, this year's third-round pick; but I'd imagine the Cowboys wouldn't be too disappointed if they both beat out Woods, who re-signed for less than a million dollars as an exclusive rights free agent. 

There are a lot of "ifs" involved with this defensive line outside of Lawrence, but the Cowboys only need a few of them to turn into hits to see a great deal of improvement up front. And they're going to need it. The Cowboys did not do all that much to address their issues in the secondary, and it seems as though their plan to replace Jones is to throw volume at the cornerback slot and hope they get a few hits. They need two or three of Chidobe Awuzie, Anthony Brown, Jourdan Lewis, second-round pick Trevon Diggs, fourth-round pick Reggie Robinson, and Worley to step up as average or better starters. They need Clinton-Dix to solidify the safety spot Xavier Woods, otherwise it might have to fall to Donovan Wilson, a sixth-round pick in last year's draft. Or maybe they move Awuzie to safety? 

There are just as many questions on the back end as there are up front, if not more -- but far fewer answers. That's why Dallas needs that front line to emerge as a true strength. They absolutely need to force more turnovers than they have in the recent past. That means getting after the quarterback and forcing him to make mistakes, allowing the young defensive backs a chance to get their hands on the ball. That means shooting through gaps and making more stops in the backfield. It means occupying blockers so Jaylon Smith, Leighton Vander Esch, Sean Lee, and the rest of the linebackers have freer lanes to ball-carriers than they had a year ago. 

The Cowboys have a ton of firepower on offense this year, and that group should be even better after adding Lamb, replacing Witten with a more athletic option at tight end, and moving on from one of the most conservative and run-focused coaches in the league to one who is much more aggressive and pass-heavy. The offense is deep-playoff-run caliber. Whether or not they make that run will depend largely on whether the defense can reach or exceed average. To get there, it's going to have to be the defensive line that leads the way.