Dom Capers or the 3-4: Who’s to blame?

Many have called for the head of defensive coordinator Dom Capers (whose head ironically can’t be taken since his contract expired). However, some have argued that the problem goes deeper than just Dom Capers and really its that the 3-4 defense is inherently flawed and that the Packers should switch back to a 4-3 scheme.

This is actually a pretty interesting question: to put it another way, is the 3-4 defense something like the wildcat offense?  What I mean by that is the wildcat offense took the league by storm in 2009 with the Miami Dolphins, but when the rest of the league had proper time to analyze and defend against it properly it slowly faded back into obscurity (see Tim Tebow).  It could be argued that the “Blitzburgh” 3-4 defense run by both Dom Capers and Dick Lebeau took the league by storm when the Packers played the Steelers in the 2010 Super Bowl and perhaps the league has caught up and has finally figured a way to beat the 3-4 defense.

To look into this I’ve used some statistics available from Advanced NFL Stats (great site by the way) and Football Outsiders (also another great site) to look at defensive efficiency for the 2012 regular season.  Just as a little primer on the metrics we’re looking at, Advanced NFL Stats’ dEPA (Defensive Expected Points Added) looks at how many favorable positions a team puts itself in regard to scoring points (i.e. getting a 1st down at your own 10 yard line is nets less EPA than getting a 1st down at the opponent’s 1o yard line since the chances of scoring at your opponent’s 10 yard line are significantly higher than at your own 10 yard line).  For Football Outsiders’ dDVOA (Defensive Defense-adjusted Value Over Average, should it be Defensive Offensive-adjusted Value Over Average?) it’s a metric that attempts to normalize defensive efficiency in regards to offensive efficiency faced.  To put that in lay terms, some defenses get lucky every year by playing poor offenses/poor divisions and/or injured offenses and should not have higher efficiencies than defenses who perhaps perform worse against a far superior offense.  Each has it’s own merits; football is a situational game (which is measured by Advanced NFL Stats), while even the best defenses will struggle with the best offenses in the league (measured by Football Outsiders).  With all that said, for defenses negative numbers are good (I’ve reversed the y-axis to reflect that)