Everyone knows all about the Dallas offense and all of the problems it can present to the Eagles on Sunday night. If you don't, check out my detailed All-22 analysis here.

What about the defense, though? Defensive coordinator Rod Marinelli has slowly, but surely turned this unit into one built in his vision. It's an "execution" style defense, meaning there are not a lot of exotic looks. The Cowboys will use the "mugged front" that the Eagles saw last week against Minnesota, but overall it's a really stingy group. Here are the three pillars of the Cowboys' success on defense.

1. This is the most disciplined defense in terms of penalties in the entire NFL. Dallas has been penalized just 34 times in its first six games.

2. It's a strong tackling team. The Cowboys allow a mere average of 4.3 yards after the catch per reception, the third-best number in the league. That's helped by the fact that it is a "rally to the ball" type of team.

3. Dallas doesn't allow many big plays. When quarterbacks go downfield, they're just 7-of-26 this year with no touchdowns and a QB rating of 48.2, good for fourth in the NFL.

What does this all mean?

Dallas forces offenses to drive the ball. The Cowboys don't give up anything cheap. They're also the 10th-ranked team in the entire NFL against the run (92.2 yards per game). The front four isn't full of dynamic pass rushers, but they play a pretty heavy rotation and all hold up fairly well in the ground game. Defensive ends Tyrone Crawford and Jack Crawford set the edges well. Defensive tackle Terrell McClain is disruptive inside. Rookie Maliek Collins is more of a penetrator than a run stuffer, but the Cowboys do have a familiar face along the line. It's a player who Eagles fans know can disrupt the run game, and that's Ced Thornton.

Shot 1 - Former Eagle Ced Thornton doesn't start for #Cowboys but is very disruptive against both the run and the pass inside for their D pic.twitter.com/8USvyd10vf — Fran Duffy (@fduffy3) October 28, 2016

After so much success in Bill Davis' 3-4 scheme over the last three years, it was a bit of a surprise to see Thornton sign in free agency with a 4-3 team. People forget that Thornton was originally brought to the Eagles to play in an attacking scheme out of college. He's got the ability to disrupt early in the down as a penetrator, and we know how strong and skilled he is with his hands at the point of attack. Thornton was initially going to start for the Cowboys, but with the kind of play they were getting from Collins, their third-round pick, the veteran was relegated to more of a reserve role inside.

Shot 2 - The guy the #Eagles must account for is LB Sean Lee. We know this all too well. Instinctive, decisive, tough, rangy. Total package. pic.twitter.com/SpuYglFdZV — Fran Duffy (@fduffy3) October 28, 2016

When you're playing the Cowboys, the player you must account for on defense, especially in the run game, is linebacker Sean Lee. Eagles fans know this all too well, as the team's leading tackler absolutely wrecked the game here at Lincoln Financial Field last year in Week 2. Lee is smart, tough, rangy and an outstanding tackler downhill. These are two plays where Lee's decisiveness and his ability to defeat blocks come into play as he hauls two ball carriers down for no gain.

Shot 3 - I see veteran LB Justin Durant make plays like this every game against run or pass. Smart and physical player #Cowboys pic.twitter.com/aa3ODThr1y — Fran Duffy (@fduffy3) October 28, 2016

The other linebacker who consistently flashed to me on tape was veteran journeyman Justin Durant. He makes plays in every game, both against the run and the pass. He's physical, tough and his experience as a longtime starter has helped cultivate good instincts. Durant really only plays in the Cowboys' base package (Dallas plays mostly nickel and dime), but for the snaps he's on the field he is always around the football.

Let's move on to the secondary, the group that has impressed me the most during my study of the Dallas defense despite the fact that they've had to cycle different players in and out of the lineup.

Right cornerback Brandon Carr is a veteran who the team signed in free agency a couple of years ago. When healthy, he has been very solid on his side of the field as a man-to-man corner. Opposite him is former Top 10 pick Morris Claiborne, who has really taken his game to another level this season. Claiborne struggled prior to this year, so he's set to hit the open market this spring. He's long. He's got great recovery speed, and more so than at any point before in his career he's playing with a ton of confidence.

At safety, veteran Barry Church is a true leader at strong safety. He's a great tackler downhill in the run game and holds up fairly well in coverage on the back end. The real standout though, is second-year defensive back Byron Jones, the team's first-round pick out of UConn in 2015. Jones is their starting free safety in their base package, but don't forget that pretty much everyone viewed him as an outside cornerback in the NFL Draft. Like Eagles safety Malcolm Jenkins, Jones plays deep, in the slot, he lines up over tight ends and he's a strong run defender. If he were a baseball prospect, you'd call him a "five-tool player" because of his ability to do anything you need in the secondary.

Shot 4 - Ridiculous play by #Cowboys DB Byron Jones vs AJ Green. Athleticism and ball skills on display here in the deep middle. pic.twitter.com/A0WOlbZXSo — Fran Duffy (@fduffy3) October 28, 2016

Here's Jones lined up as a deep safety in the middle of the field against the Cincinnati Bengals. Star receiver A.J. Green is lined up in the slot and is going to run a deep over route across the field, through Jones' area. Watch Jones react to this route and track the ball in midflight over his shoulder and leap up to the highest point to get the ball on the ground.

Shot 5 - Jones is also a really effective slot corner for them in base and in sub. So versatile vs TEs and WRs alike #Cowboys #Eagles pic.twitter.com/epu4Kf7ffv — Fran Duffy (@fduffy3) October 28, 2016

That play came with Jones lined up as a deep safety, but in the slot he makes plenty of plays too. Whether he's lined up against a shifty route runner like Randall Cobb or a big tight end like Zach Miller, Jones is physical, disciplined, athletic and his ball skills reign supreme in one-on-one matchups. You see his ability in both press coverage and off coverage on the two plays above, getting two passes on the ground.

Shot 6 - Mo Claiborne has taken his game to another level. Grossly underthrown pass here, but great job tracking and finishing for the INT pic.twitter.com/4BkaywEzIH — Fran Duffy (@fduffy3) October 28, 2016

This pass is severely underthrown downfield, but Claiborne does a great job not only tracking it vertically but also finishing in the air for the pick. You hear the word "confidence" thrown around often with players in the secondary, and it's so important. In today's game, defensive backs are always going to give up passes. It's how they respond after those catches that separates bad from good and good from great. It's a reason why the Eagles like rookie Jalen Mills so much, not just because of his physical traits but also because of his short-term memory and the swagger he carries on the perimeter. That's something I see on tape this year from Claiborne, who finally appears to have turned into the corner the Cowboys hoped for when they took him in the 2012 NFL Draft.

Shot 7 - Three plays here by Mo Claiborne. Confidence is through the roof right now. Playing better than at any point in his career #Cowboys pic.twitter.com/PHSKB5A2Pn — Fran Duffy (@fduffy3) October 28, 2016

There's three plays in that clip, and three distinct examples of his improvement as an NFL corner. On the first play, Claiborne breaks up a pass on a double move downfield, an issue he's always had since he arrived in the league. He doesn't panic once he's beaten initially, but instead he works to get back in-phase to get the ball on the ground.

On the second play, Claiborne is in Cover 2 (Marinelli's go-to zone concept). Claiborne has always had some issues with his zone responsibilities in the Dallas scheme. Here, he sinks perfectly into the void between him and the safety (a soft spot in the zone I refer to as the "Turkey Hole") and gets the pass breakup against Cincinnati.

On the third play, it's fourth down in the fourth quarter and the Cowboys need a stop. He's in man coverage. He stays over top of his man and at the catch he comes down and makes the stop short of the sticks for a turnover on downs to get the Cowboys the football. Claiborne has improved his game in every facet this year, and is certainly a player the Eagles' offense will have to account for on Sunday night.