While it certainly remains to be seen exactly what Billy Davis has in store for the Eagles defense, it's obvious that we're in for changes. But just how big will those changes be? The answer may come from a 2009 interview Davis did with Pro Football Weekly while he was still LB coach of the Arizona Cardinals.
The scheme that team ran looked a lot like a 3-4, but was in reality a 4-3 "under" system. It's actually very similar to the Bill Parcells, Bill Belichick, Dom Capers front.
Davis described the under formation as "almost" a 3-4 and his description of it sounds similar to what the Seattle Seahawks were running this season and basically what Pete Carroll did as USC.
The basic idea is that the defense slants to the tight end side. The NT lines up on the center's shoulder on the TE side and the SAM linebacker lines up right over the TE. The DE on that side moves to the shoulder of the OT (this would likely be Cullen Jenkins but maybe Trent Cole in certain situations) , while on the other side, the DE will typically play a 5 technique. This would be where you'd likely see Fletcher Cox.
The other linebacker, which he calls the "predator," lines up on the weaks
Explaining the scheme of Eagles defensive coordinator Billy Davis
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