Dallas Cowboys defensive coordinator Rod Marinelli is a disciple of legendary defensive coordinator Monte Kiffin. Along with Tony Dungy, Kiffin developed a defense known as the Tampa 2. It was a very specific type of coveragethat depended upon execution more than deception.
In the Tampa 2, the four defensive linemen rushed the passer. The back seven dropped into zone coverage. Arguably the most important player was the middle linebacker. His job was to coverage an inordinate amount of ground. His zone began short, but he also had to be able to drop into the deep middle of the field, taking away the middle third while the safeties covered the deep thirds of the field on the outside.
On defenses like the 2002 Buccaneers, it didn't matter whether the offense knew this was the what the defense was running. Success was based upon execution.
Marinelli does not stick strictly with the Tampa 2. The true Tampa 2 has gone out of style in the NFL as the offenses have adapted and adjusted.
Every zone coverage has holes. (If there were a zone coverage that didn’t have holes, defenses would play it on every snap.) Cover 2, with its static back seven defenders, has obvious holes. (Mainly, the deep-intermediate outside window above the corners and in front of the safeties, and the seams beyond the linebackers and in front of the safeties.) As the scheme became more prominent, offenses naturally focused more on exploiting those holes.
Marinelli's defense in Dallas mixes its coverages, but many of the core principles of his defense are derived from the Tampa 2.
Trying to Avoid the Big Play
Marinelli does not like to blitz. A year ago, Dallas blitzed less than any team not named Jacksonville. The concept was simple. By only rushing four men on most plays, seven drop into coverage. With seven guys back, there are more people to cover and make a tackle in case somebody makes a mistake.
It is the opposite approach of Todd Bowles. Bowles wants to force you into making mistakes. He attacks you. He sends lots of blitzers at the quarterback to force a mistake. That means less guys in the back and lots of one on ones.
Everybody in the back has a lot of pressure on him in a Bowles defense. If one guy makes a mistake, it can be disastrous. It is high risk-high reward. It is also why the Jets invest so much money in their secondary.
Marinelli plays things more conservatively. The aim is to avoid the big play. There are less pass rushers, which means less chance of something big happening for the offense. It also means more guys in the back. The players can keep things in front of them to prevent the big play. Sure enough, the Dallas defense has allowed the seventh least plays gaining 20 yards or more from scrimmage.
It is difficult to execute time after time after time for eight, nine, or ten plays. There is a tradeoff here. This type of defense at least in theory is trying to prevent the knockout punch. It can allow lots of yardage and death by a thousand cuts because it is less apt to deliver the knockout punch itself.
Marinelli did get more aggressive a few weeks back against Washington, but that was viewed as a necessity. Against a quarterback who likes to get the ball out quickly and isn't successful on long-developing plays, will he drop guys in an attempt to disrupt short passes?
Lots of One Gapping
The lack of a blitz leaves the bulk of the pass rush to the defensive line. This means those guys have to get to the quarterback. You will see some defenses where defensive linemen are responsible for eating up space. Their job might be to occupy offensive linemen and keep linebackers clean. That is not as much the case in this defense. Their job is to get up the field and shoot the gaps.
That is what the assignment might look like against the pass. Since these guys are playing the gaps, it gives the linebackers a responsibility to handle gaps against the run.
Speed Over Size
As you might imagine, because the defensive line's job is to penetrate rather than occupy blockers and keep other defenders clean, an emphasis is put on speed over size. A defensive line that needs to tie offensive linemen up would have bigger guys who eat space. This defense does not emphasize that.
Sure enough, SB Nation's Cowboys site, Blogging The Boys, estimated the Dallas defensive line to be the smallest in the league among 4-3 defenses back in August.
This could make it the type of game where Chris Ivory pounding on a defense might wear it down over the course of the evening. It is also an interesting matchup between a defense willing to concede short gains against a quarterback who is typically at his best dinking and dunking.