— Getting the defensive linemen to accept the reality of the Philadelphia Eagles' new 3-4 base wasn't all that difficult.
But getting them to adjust to the two-gap methods that go with it took some work. Fletcher Cox and Cedric Thornton would be moving from the inside to end spots lined up directly across from the tackles.
Vinny Curry, conversely, was required to move in from the outside shoulders of tackles and tight ends, where he too wouldn't be able to make as many plays that can be measured statistically as he could in a 4-3 system, which he, Cox, Thornton and current outside linebackers Trent Cole and Brandon Graham were acquired to play.
In fact, he couldn't even get on the field until Week 3, when he rewarded the coaches' patience with his first career sack. He's had two more since as he continues to make his presence felt on just about every snap.
Now, as they get set to visit the Green Bay Packers today, the Eagles are the only team besides the Kansas City Chiefs to hold opponents to 21 points or less in each of the past five games. And coordinator Billy Davis on Tuesday pointed to a huge reason behind that success.
"I think one of the strengths of our defense right now is the run game and the run defense," Davis said, "and it starts with those two-gap techniques that the D-linemen are getting better and better at. I just made a big point about Vinny Curry, his technique in the two-gap and the technique that [defensive line coach/assistant head coach] Jerry [Azzinaro] has been teaching these guys since Day 1. They're all improving at a real nice clip.
"And I think that's one of the things we feel confident about competing and stopping some run games to get them to third down and more winnable for us. I think the techniques that we taught from day one are really starting to show themselves, and that's a product of playing the run game better than we did earlier in the season."
What's more, the staff felt good enough about those players and rookies Damion Square and Bennie Logan to trade away their only true nose tackle, Isaac Sopoaga.
Logan was rewarded with his first career start as a result. Square was in the mix too as a reserve.
In the end, it was one happy rotation that is getting better with every snap.
"We start in a very early rotation to make sure that everybody stays fresh throughout the game," Davis said. "I thought both of the [rookies] did a great job of staying in their technique and taking care of the little things, and they played well because of it."
The centerpiece of this conversion, though, is Cox. Without him, it would have gone nowhere.
Like many who go from a one-gap to a two-gap, Cox has struggled to match last year's numbers. Numbers , though, are only a fraction of the complicated evaluation process that has him accurately valued much higher than he was last season, when his 5.5 sacks were the third-most by an Eagles rookie.
Cox has 3.0 sacks through nine games this season, which puts him on a pace for less than last year, when he made just nine starts. Cox also is on pace to fall well short of last year's 46 solo tackles. Doesn't matter, considering the plays he's helped so many others make by occupying blockers up front without complaint.
The 3-4 can be such a scourge for down linemen that it can drive them out of the game, or at least to seek employment elsewhere.
That's what former Washington Redskins defensive tackle Albert Haynesworth did after having it written in his free-agent contract that he can become a free agent if the team switches to a 3-4. Well, it did.
No such selfishness on this squad.
"Being able to adjust on the go was the main thing," Cox said. "But at the end of the day, I say that I don't believe I play two-gap, I just whip the man across the line of scrimmage.
"The [two-gap] doesn't bother me. It's all about sacrificing for your team. Sometimes on some downs, you have to sacrifice for the linebackers."
Cox still considers himself primarily a 4-3 defensive tackle. "But things have changed. I have to be able to adjust on the go, just like I said."
That's a technique Curry is still trying to master but getting better at it as he continues to be worked into the rotation after being inactive for the first two games.
"It's a big adjustment for me," he said, "but it's my job, so I do it to the best of my ability."
With the multiple looks the team gives in any given contest, the two-gap technique is not called for on every play, either. So there's usually plenty of other plays in which they have a little more freedom to improvise.
That doesn't even matter to Square, who made the team as an undrafted free agent two years after Thornton did the same thing.
"You have the three guys up front so you can do what you want to do on the back end," Square said. "That's the name of the game in the 3-4."
Thanks to the right personalities, the Eagles are beginning to thrive up front, even though their skill sets still lean the other way.