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Don't try to pigeon hole the Buffalo Bills as a 3-4 or a 4-3 defense.

Now that defensive coordinator Mike Pettine is pulling the strings for the Bills, expect a lot of the same that we saw from him with the Jets: a mix of both fronts, a lot of nickel packages and a game plan-specific defense (via BuffaloBills.com).

It's a situation where I think people try to compartmentalize too much, and just broad stroke it. 4-3? 3-4? What are you? And my answer that question is yes to all of the above. We are a multiple-front, attacking, pressure-style defense. We're going to play man coverage, we're going to play zone coverage. What we’re going to do defensively is take advantage of what our players do well. [ ...] I'm not bringing any defense here; this is going to be the Buffalo Bills defense. It's going to be built around the explosive athletes that are here, starting with the front—that's the solid foundation here—moving to the linebackers and the secondary that's stacked behind them.

The Bills spent years building toward a 3-4 defense, but switched to a 4-3 scheme last season under defensive coordinator Dave Wannstedt. The result is a mix of players that can play different roles depending on the front.

Most of the players have their roots in the 4-3 defense, but some—such as linebacker Manny Lawson and nose tackle Marcell Dareus—come from, and have excelled in, a 3-4 defense. Almost every player, though, has experience in both fronts—for better or worse.

With so many players capable of doing so many different things, it's tough to project exactly who will be filling what role, but with help from Alex Miglio's template for diagramming defenses, let's take a look at what the Bills defense could look like in 2013.

4-3

This is the defense as we last saw it in 2012, with some tweaks across the board.

The linebacking corps has been overturned completely, and there is a slight competition at defensive end now between Mark Anderson and Jerry Hughes, acquired via trade for former Bills inside linebacker Kelvin Sheppard.

The Bills also added Bengals linebacker Manny Lawson as their biggest free-agent signing of the offseason, and chances are strong he'll start on the strong side this year. Nigel Bradham was the strong-side linebacker last year, but his previous experiences came both inside and on the weak side. He emerged in an unfamiliar role, and he could return to one of his more comfortable roles now that there are options for the other spots.

Kiko Alonso has the skill set to play outside or inside. He lined up all over the place for Oregon, but he was primarily an inside linebacker. His athleticism is something the Bills have sorely lacked inside, and he has the versatility to blitz or drop into coverage from that spot. One concern with Alonso is that he's not disciplined against the run, which is an absolute must for an inside linebacker.

Obviously, there's nothing too exotic here schematically, but the 4-3 could still allow for some versatility. Defensive lineman Alex Carrington is a more natural 3-4 defensive end, but could line up inside on passing downs, or maybe even on one of the ends in obvious running situations. At linebacker, perhaps Bradham lines up inside and Kiko Alonso rotates with Bryan Scott on the weak side.

Mario Williams was a right defensive end with the Texans, but moved to the left side last year because he is far better setting the edge against the run than Anderson. Mario could move back to the right side if the Bills wanted to give Carrington a try at left defensive end in four-man lines, and he could even kick inside to the 3-technique on passing downs if the Bills want to get him matched up on a guard.

3-4

There is little doubt in my mind that we'll see some elements of the 3-4 defense for the Bills in 2013. It was the predominant defensive front for Pettine in his time with the Jets. The question comes with where the players will line up.

Anderson and Hughes both have experience playing outside linebacker—Anderson at the end of the 2011 season, and Hughes with the Colts in 2012.

Anderson's move to outside linebacker for the Patriots was necessitated by an injury to defensive end Andre Carter—an injury which forced the Patriots to make wholesale changes in their defensive scheme. Hughes already has a jump-start on the learning curve of his responsibilities in the 3-4 defense, having played in former Ravens defensive coordinator Chuck Pagano's defense last year.

As mentioned earlier, Manny Lawson's roots are as a 3-4 outside linebacker with the 49ers.

He was used predominantly as an edge rusher, but he was asked to cover from time to time. His strengths are as a straight-line player, though, and that's likely how he'll be used.

The problem, however, is what to do with Mario Williams. He played 3-4 outside linebacker sparingly in 2011 as part of Texans coordinator Wade Phillips' scheme, but he suffered a torn pectoral muscle five games into the season and wasn't brought back as a free agent in the offseason.

He could play outside linebacker, or at 6'6" and 292 pounds, the Bills might consider using him as a 5-technique defensive end in a 3-4. That would certainly make sense if this is a one-gap scheme where every defensive lineman's job is to get upfield by splitting their gap and beating their man. Perhaps Mario Williams could be utilized similarly to J.J. Watt with the Texans in that respect, carrying out a little of both duties. They could also just put him on the outside and turn him loose.

Some of these ideas may seem off the wall, but if you believe in having the best players on the field, this is a good starting point.

The addition of defensive tackle Alan Branch could change things. He has experience as a 3-4 defensive end and at nose tackle, so he could be used in either spot. He could flex with Kyle Williams, who has also played nose tackle in his career.

In this instance, though, Williams lines up on the edge at right outside linebacker. This is if the Bills feel good about his abilities in space. If not, it could remain Anderson or Hughes on the edge.

5-2

If the Bills are going to convert to a 3-4 look, the 5-2 could follow. That's with five defensive linemen and two linebackers.

It borrows looks from both the 4-3 and the 3-4. The defensive line is aligned similarly, but with the Williamses and Dareus shifted to the right, making room for Lawson on the edge, as in the 3-4.

This could also be called a 4-3 "Under" front, with the defensive line shifted to the offense's weak side and the strong-side linebacker playing close to the line of scrimmage.

This could be a front to disguise pressure, with the possibility that Lawson could drop into coverage.

The Jets ran a 5-2 front at times in 2012, with Calvin Pace and Bryan Thomas lined up on the edges. In that scenario, the alignment was more a result of the Jets' inability to stop the run. It may have also had to do with Pace and Thomas' ineffectiveness in space and in coverage, but here, the Bills have some versatility in that regard. Anderson and Hughes won't likely be dropping into coverage much, but Lawson could be used somewhat in that role.

Nickel

This is where things really get interesting. We have heard Mike Pettine say that the nickel defense will be the base, but which version are we talking about?

It could be a 4-2-5 nickel, the front six shown above.

Nothing differs between my vision of the 4-3 and the 4-2-5 except that presumably, one of the the top linebackers has to come off the field. Alonso and Bradham could line up at either weak- or strong-side in this package, but Lawson and Scott would likely be locked in on the strong and weak side respectively.

It could also be a 3-3-5 nickel, the front shown here.

Drawing them into specific spots on the line was difficult; will Mario Williams line up as a 5-technique as shown above, a wide-9, or will the entire line shift to the left with Kyle and Mario Williams lined up over the left and right tackles respectively?

Will the line be two-gapping to hold at the point of attack, or will they be one-gapping to shoot into the backfield? They could even run a mix, with Kyle WIlliams and Marcell Dareus two-gapping on the inside and Mario Williams and another defensive end or linebacker shooting up the field.

Mario Williams

The high-priced defensive end warrants his own section, especially with news that Pettine expects Mario Williams to line up "all over the place" for the Bills.

This really could be its own article, but Mario Williams could be used like Cowboys linebacker DeMarcus Ware, whose position of "Joker" linebacker is indicative of his status as a wild card in the defense. Ware lines up all over the defense: inside and outside both on the line and at linebacker.

At Mario Williams' size, his most likely landing spots are on the edges or as a 5-technique in three-man lines, or in any spot on a four-man line. It wouldn't be surprising at all, however, to see Mario Williams stand up and shoot a gap on either side of the guards. He's never done that in his career,

As with the entirety of the Bills defense, the beauty of it is the versatility.

Erik Frenz is also a Patriots/AFC East writer for Boston.com. Follow Erik on Twitter and "like" the AFC East blog on Facebook to keep up with all the updates. Unless otherwise noted, all stats obtained from the Sports-Reference.com network, and all quotes obtained firsthand or via team press releases.

