The Buffalo Bills transitioned to a 3-4 defense in 2010. The lack of personnel to fit the scheme forced Chan Gailey and defensive coordinator George Edwards to play more 4-3 defense as the year wore on. While Buddy Nix will continue to draft personnel for the 3-4 defense, Gailey said that the team will run a multiple front defense. The hiring of Dave Wannstedt, historically a 4-3 coach, reinforces the point. I expect Buffalo to run three to four variations of their defense. Here's how Alabama junior Marcell Dareus would fit in.
Bullough-Fairbanks 3-4
This is the base 3-4 defense employed by members of the Bill Parcells coaching tree. This defense is very stout when the three defensive linemen are capable of playing two-gap assignments, but is vulnerable to two-tight end offenses.
3-4 Over (also known as the 4-3 Over)
This defense is effective at penetrating and disrupting the offense, but can be run against effectively by teams that can rush with power.
46 Defense
This is a difficult defense to play against when run effectively, as seen in New York and Philadelphia. Effective West Coast or possession-passing teams that can protect the quarterback can beat this defense.
Marcell Dareus in the Bullough-Fairbanks 3-4 Defense
Dareus is capable of playing both a two-gap assignment and one-gap assignment. Dareus is somewhat similar to B.J. Raji in terms of size and lower body power, and occupying two gaps was something he regularly accomplished at Alabama.
Dareus can also play nose tackle, though this somewhat negates his ability to penetrate and make plays on the move.
Dareus in the 30 Over Defense
While the Bullough-Fairbanks 30 front would become the Bills base defense, the 30 Over becomes a variation to throw at offenses out of the same formation. This defense is similar to the defense that Dallas played under Wade Phillips. Dareus has enough burst off the line of scrimmage to cause offensive line blocking schemes to account for him, even if left on the backside. Similar to how Buffalo could use Nick Fairley, Edwards could walk Dareus down into the 3-technique position for a defense that looks like this:
While not as explosive as Fairley, Dareus' strength combined with quickness needs to be accounted for. He may be a half-step slower than Fairley bursting into gaps, but his size and strength would make him difficult to dislodge once in the gap.
Dareus in the 46 Defense
Edwards can play this defense with two-gap defensive tackles, or one-gap defensive tackles. As in the 3-4 schemes, Dareus can play both assignments well, which allows the defense to shift between schemes without changing personnel.
Assessment
Unlike Fairley, Dareus is a schematic fit for any defense that Buffalo runs, not just one-gap schemes. Adding Dareus to Kyle Williams and Torell Troup would give Buffalo tremendous talent on the interior of the defense. Dareus is a very stout defender, which would allow Buffalo to use multiple schemes out of similar sets and personnel packages.
If Dareus is available at the third overall pick, GM Buddy Nix might be hard pressed to pass him up.