Fewell tweaking original defensive scheme (Photo Source)

In two seasons as part of the Buffalo Bills' coaching staff, defensive coordinator Perry Fewell - under the tutelage of long-time defensive coach Dick Jauron - has completely revamped the Bills' defense, both in terms of philosophy and personnel.  Gone are the days where big, lumbering defensive linemen paved the way for a group of excellent linebackers to make plays - the essence of the 3-4 defense used from the Super Bowl era right up through the early years of this decade.  Lighter, quicker, and faster is the motto that Fewell and Jauron have preached for the past two seasons.

In 2008, however, that motto has been altered to a more appropriate and idealistic phrase: bigger, faster and stronger.

Earlier this off-season, we took a look at how 2008 personnel changes have left this defense bigger and stronger, especially in the front seven.  Those were the obvious changes.  But even prior to this off-season - in fact, even as far back as 2006 - Fewell has made some changes schematically that will likely carry over to his "new" defensive philosophy of 2008.  Let's examine...

2006: Coverage Shifting
Back in the early portions of 2006, when the Tampa 2 defense was installed in Buffalo (Fewell brought it with him from Chicago, where he coached it under Lovie Smith), the Bills employed a scheme in which their two starting cornerbacks - at that time, Nate Clements and Terrence McGee - would line up on specific sides of the field, play in and play out.  That scheming was exploited quickly by opposing offenses; by the end of the '06 season, Clements was matching up with the opposition's top receiver.

In 2007, Fewell reverted back to the cemented corner philosophy, as Clements' departure left the team without a clear-cut top cornerback.  After giving up plenty of big plays in the season opening loss to Denver, however, that philosophy quickly reverted - Fewell then employed a mix of cementing and matching for the remainder of the season.  Without a true "lock down" cornerback, Fewell didn't have the personnel to switch to a match-up secondary exclusively; it explains, in part, why Jabari Greer was left to cover Randy Moss so frequently.

The Front Seven and the blitz
Fewell's biggest changes in the front seven (again, aside from the size changes) will actually come in 2008; we'll get to those in a moment.  For two seasons, the Bills had a rotation of defensive tackles that would play exclusively the one-technique or exclusively the three-technique; linebackers were meant to be light and speed-focused solely in the zone defense's gap-control run scheme.

After injuries decimated Buffalo's defensive end corps in 2007 - and it didn't help that the defensive ends who did play suffered a steep drop in production - Fewell started using the blitz far more frequently to attain the much-needed pass rush a Tampa 2 needs than he did in 2006.  The blitzes were creative, too - the Bills offered some of their most exotic post-3-4 looks in a 25-24 Monday Night loss to the Dallas Cowboys.

What's Changing in 2008
Now, Buffalo's defense will likely function a bit differently for the start of the 2008 season.  Gone are the exclusive one-tech and three-tech defensive tackles; Marcus Stroud, Kyle Williams, Spencer Johnson and John McCargo will each be asked to play both positions, and which they'll be playing will be decided by a given offensive play.  Fewell is now asking his tackles to line up according to how the offense lines up, switching between one-tech and three-tech at will.

The blitz will likely remain a more prominent staple of the scheme as well.  Clearly, Fewell prefers not to blitz (see: the entire 2006 season), but Buffalo's defensive line won't be able to generate pressure every play, and the team's three linebackers - especially Angelo Crowell - are very solid blitzers.  Don't expect to see a lot of it, but the Bills will be blitzing more often than they would have when Fewell first took the job.

Since the blitz should be featured more, expect the match-up corner philosophy to gain prominence as well.  That should become the main defensive back philosophy once top draft pick Leodis McKelvin emerges as a starting cornerback - he's by far the most talented corner on the roster, and with time, he should be able to match up with an opponent's top receiver each week.

The changes that Fewell are employing are pretty major tweaks that will help Buffalo's defense become much more flexible and effective, but the basic philosophies remain - penetration and speed are still the main focuses of this defense.  It's still predominantly a zone defense.  You'll still see every player flocking to the ball on every play.  With added size and the proper tweaks, that speed/flocking philosophy should be much more effective in 2008.