Possible clues about the Eagles' defense

So this here is the Eric Edholm article about which you've likely heard, some time in the past 24 hours, if you're a Philadelphia Eagles fan. It's from 2009, when Billy Davis was the Cardinals' linebackers coach, and it features Davis explaining in detail the hybrid defensive alignment the Cardinals were running at the time. Something between a 3-4 and a 4-3 with "under" principles. Davis, who would soon thereafter become the Cardinals' defensive coordinator, has just landed a job as the Eagles' new defensive coordinator under Chip Kelly. And while it's no sure thing that he'll install the exact same defense he was using in Arizona, the story offers some potential clues about the way the Eagles will run their defense with Davis in charge.

The "under" front Davis employed in Arizona, which shifts toward the tight end side, looks like a 3-4. But it doesn't adhere strictly to 3-4 principles, and as you read the details in Eric's story you can start to believe the Eagles' current 4-3 personnel might fit the new defense better than initially thought:

But in the 4-3 'under' front, like the Cardinals use as their base defense which looks similar to the 3-4 to the naked eye, the biggest difference is in the outside linebackers. The strong-side linebacker is still outside the tight end. But the other outside guy -- the Cardinals call this player their "Predator" -- is almost always rushing the passer, although the Cards will occasionally drop him into covers to mix things up. Other differences: The nose tackle shades to the A-gap (in between the center and the guard) on the tight end side, and the end on that side moves between the tackle and tightend.

In this arrangement, the Eagles' "predator" could be either Trent Cole or Brandon Graham. Either one fits the mold as a pure pass-rusher with a great first step and, especially in Graham's case, a high motor. I'm not sure either of those guys translates to the strong-side linebacker role in this scheme, and Mychal Kendricks seems suited to the weak-side linebacker role. They may need to find a more traditional stand-up linebacker and either rotate or decide between Cole and Graham, since you have to think Cullen Jenkins and Fletcher Cox are the ends and the nose tackle is someone not yet on the roster.

Another interesting aspect has to do with veteran middle linebacker DeMeco Ryans, who would remain an extremely important player in a scheme such as this. It's true that one of the reasons the Texans traded Ryans to the Eagles was that he'd become an imperfect fit once they switched to a 3-4, but that had more to do with Ryans' salary and the emergence of fellow linebacker Brian Cushing as a superior three-down option than it did Ryans' ability to play the scheme. And if Davis runs a system similar to the one he ran in Arizona, Ryans takes on a vital dirty-work role:

The only player in the 4-3 'under' who is left uncovered is the "Mike," or the middle linebacker. In the Cardinals' scheme, that's usually Gerald Hayes. "That's my thumper, more of a thick guy," Davis said, circling the capital M on his piece of paper. "In the 'over' front, when I was in Atlanta [2001 to 2003], we put Keith Brooking -- we were actually playing an even scheme, too -- but we stacked Keith right behind the three [technique] and he got to run and make players and use his athleticism, and he made his first Pro Bowl playing behind the three."

But in this scheme Hayes, listed at 249 pounds ("or a little less than that," he admits with a wink and smile), is the only uncovered linebacker. That means he often will be taking on 300-pound guards head on. On Sunday, it could be Steeler ORG Darnell Stapleton and his 305 pounds that will meet Hayes more than once. "You don't think about," Hayes says, "you just do it. You can't worry about taking those guys on. It comes with the territory."

Ryans is listed at 247 pounds and seems a natural for that role, which would answer one of the big questions about the Eagles' current personnel transitioning to a new alignment.

Again, we will learn more about all of this in the coming months, and the way the Eagles line up on defense this year could look different even from what Davis has run in the past. But this is an interesting look at the new guy and where he comes from philosophically, and I found it interesting. Hope you did, too.