The Packers are making a defensive switch from the 4-3 scheme to the more challenging and sophisticated 3-4.  Their linebackers are going to be put under enormous pressure this year, and with some of the offenses in the NFC North, this makes the Green Bay Packers' defense one to watch in 2009.

Being a Steeler fan means that I've watched the 3-4 defense since Cowher was named the head coach in 1991.  We've been blessed here with great linebackers for virtually that entire time, but since the philosophy has never wavered, the Steelers have always been able to draft their type of guys that fit the scheme.  The first year of any kind of major philosophical switch is a key one, but this one might be the most challenging of them all.

In 2008, the Packers fell back into the pack with a 6-10 record, one year after reaching the NFC Championship Game.  It was really the injuries that crushed the Packers defense, because once the injuries mounted, failure upon failure hit this team.  They fired their defensive coordinator because they needed a fall guy, and the new one (Dom Capers) is a long-time 3-4 proponent.  One reason?  Capers - along with LB coach Kevin Greene and secondary coach Darren Perry - are all Cowher/Steeler alums. 

The 3-4 becomes such a difficult defense because it, more than the 4-3, requires that all seven front defenders do their job correctly, make the correct reads and play their position exactly to plan without regard of what anyone else does.  When this works well - in New England, Baltimore or Pittsburgh - you see the results.  When it fails, it usually does so in dramatic and explosive fashion.  A bad 3-4 play can easily take a normal 3-4 yard run and have it turn into a 11-12 yard one.  It can take a well-defensed pass defense and allow a big gainer or worse.  It's this tricky nature of the defense - the fact that all 11 men really do have to be constantly on the same page - that creates a very small margin of error in this defense.  When a team does it's job well, the 3-4 creates opportunities in the pass pressure that a 4-3 simply cannot match.  The 4-3's pass rush scheme is usually straight forward - the edge rushers are fast and get upfield quickly, and the two interior guys put forth a huge push and collect blockers.  The 3-4 allows defensive coordinators the luxury of changing sides, overloading a side with pressure (often resulting in television announcers claiming the move is a 'blitz' even though only 4 guys rush the ball) and can wreak havoc upon the offensive reads because they simply aren't sure where the pressure will come from.

In the Packers favor they have a long-time 3-4 coach in Dom Capers.  As a head coach he never quite tasted a ton of success, but as a defensive coordinator he's great.  With him he brings coaching talent that understands the 3-4 game, and knows how to work within it.  Plus, the Packers have drafted well at LB, and this defense gives them the ability to work wonders with that athletic talent.

On the flip side, however, the Packers play 4 games against teams that figure to have already top offenses in the run game (Vikings) and one that ought to be far better because of the new QB talent (Chicago).  The Lions, too, will probably feature as much of a run-heavy offense as they can.  This means that the Packers will be put to the ultimate test this year.  If that 3-4 scheme isn't clicking by the time the Minny Vikes come calling (with or without Favre), the Vikings are going to run all over them courtesy of All Day.  If it's not clicking, then Cutler will have his way with the Pack's D (with or without quality receivers).  Plus, the Packers have to play the AFC North this year, a division that has 3 teams that figure to have pretty solid or better offenses (Cincy, Pittsburgh & Baltimore).  That's no easy task for a new defense.

For Packer faithful, it has the potential to be a long year if the scheme's complexities aren't mastered quickly.  But if Capers et al can work some magic, it may reinvigorate a team, and put the Packers back solidly into playoff discussion.  As I said, it bears watching carefully.