A recipe for disaster, right?
The Texans improved from 29th to fourth in points allowed, from 30th to second in yards allowed, from 32nd to third in pass defense and from 18th to 12th in takeaways.
"Wade came in [with a] proven track record, and just turned things around," said Eagles linebacker DeMeco Ryans, who played on that defense, along with fellow Eagles linebacker, Connor Barwin. "Guys just jumped on board and made the decision that, whatever it took, we were going to be good.
"We had to focus in a little more, because we were coming off a lockout and had to get the defense down as quickly as possible. We didn't do much. We stayed simple and guys knew what to do, and we played fast."
Said Barwin: "We had good coaches and good players. That usually helps. But the one underlining factor was that change is good, change is exciting.
"When you do things the same way, things can get stale. I don't know why, but they just do. I think when Wade came, he brought this kind of excitement with the change where everybody bought in and everybody was enthusiastic about training camp, about learning and figuring out the defense. I think that was one of the big reasons we were so successful right away."
Ryans, who was part of an Eagles' defense that finished tied for 29th in points allowed and 31st in takeaways last year, and Barwin, who signed with the team in March, both are optimistic that the Eagles can experience the same kind of leaps-and-bounds improvement as the Texans as they make the move from a 4-3 to a 3-4 under defensive coordinator Bill Davis.
Of course, that's what you would expect them to say. And after watching Davis' defense get roughed up by Tom Brady and the Patriots at NovaCare the last 2 days, it's easy to think it's probably just wishful thinking.
The truth is, it's still way too early to make any absolute judgments about the defense. Davis still is trying to figure out exactly what he has and how best to utilize it.
As Barwin correctly pointed out, it helped that the '11 Texans defense had a lot of good players. They drafted defensive end J.J. Watt and rush linebacker Brooks Reed that year. They signed one of the league's top cornerbacks, Johnathan Joseph. And they already had talented, young playmakers such as Barwin, Ryans and defensive end/linebacker Mario Williams.
When you look at the Eagles' defensive personnel right now, there still are a lot more questions than answers.
Can Trent Cole and Brandon Graham make the transition from hand-in-the-dirt ends to outside linebackers? Despite all of the changes in the secondary, is it really any better than last year's group, which gave up a league-worst - and franchise-record - 33 touchdown passes? Do they have enough good, block-occupying big bodies up front to free up the linebackers to make plays in the new scheme?
"It's a lot like Houston [here]," Barwin said. "Everybody's buying in, everybody's excited to learn. There's growing pains and we're figuring things out on the run. But if everybody's into it, if everybody believes in the defense, we'll be fine."
Barwin, like Cole and Graham, was drafted as a defensive end (he was a tight end his first 2 years at the University of Cincinnati before moving to defense). He was moved to outside linebacker when they switched to a 3-4 and had 11 1/2 sacks the first year of the switch.
"For me, I'm more of an outside linebacker," the 6-4, 260-pounder said. "You can just look at me and see I look like an outside linebacker. So [the switch to a 3-4] was perfect for me.
"The one thing any [4-3] d-end should think about is you want to be in a 3-4 because it opens everything up for you. You might have to be a yard farther from the [offensive] tackle. But when you're a d-end, you're in the same place every time. The tackle knows what you're doing. When you play outside linebacker, it adds a lot more creativity to what you can do.
"If you buy in to that and understand the concepts of what you're doing, you can really confuse the tackle a lot and it will open things up for you. I've told Trent and Brandon from the beginning, this is going to be really good for you if you kind of just learn to understand what you can do with it."
Not every 4-3-to-3-4 switch has enjoyed the kind of overnight success the Texans had in '11.
When Mike Shanahan took over the Redskins in 2010, he brought in Jim Haslett to run his defense. Haslett deep-sixed the 4-3 the 'Skins had used under Greg Blache and put in a 3-4.
That first year, the Redskins finished 17th in points allowed, 31st in yards allowed, 26th against the run, 31st against the pass and 15th in takeaways.
"It takes a little time to get the personnel you want more than anything," said Redskins inside linebacker London Fletcher, who went through the switch. "It's hard in one offseason to do a complete overhaul on your personnel to go from a 4-3 to a 3-4.
"Sometimes, you have square pegs you're trying to fit into round holes. It took us two offseasons to get the personnel we wanted at the outside linebacker position and the types of ends and nose tackle we wanted."
Barry Cofield ended up being that nose tackle. He spent his first five NFL seasons playing in a 4-3 scheme with the Giants before signing with Washington in 2011. He admitted it took him a while to make the transition to the nose.
"You've got to play with great pad level [as a 3-4 nose tackle]," he said. "You have to learn that you really have to occupy yourself with blockers. In the 4-3, you're trying to find the ball, trying to make plays.
"In the 3-4, you can make a great play without even seeing the ballcarrier and just keeping that linebacker clean. You've got to learn to sacrifice yourself. Once you get over that hurdle, it's a lot of fun to play."
Patriots coach Bill Belichick downplayed the differences between a 3-4 and 4-3. Pointed out that most teams, including his, employ multiple fronts.
"I personally never felt it was that big a deal," he said. "People called us a 3-4 team when I was the defensive coordinator of the Giants. But [linebacker] Lawrence [Taylor] rushed 85 percent of the time. So everybody treated us like a four-man line. But to the media and the fans, it was a 3-4.
"Somebody has to play on the end of the line of scrimmage. Whatever you want to call him - linebacker, defensive end, crash end - whatever term you want to use, a guy has to play inside of the outside guy on the line of scrimmage.
"I don't think the spacing, it's important, I'm not saying that. But I don't think it's that big of a deal. We play an even front. We play an odd front. I'm sure Philadelphia will do the same thing."
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