The Carolina Panthers defense improved by leaps and bounds in 2013 and became the single biggest reason 7-9 quickly became 12-4. Looking at why this happened the answer is clear, double-dipping at DT was a small stroke of genius.

To see the shift we dive into DVOA, defense-adjusted value over average. You've likely heard the metric before, which is quickly becoming the gold standard in how we analyze teams due to its almost infallible reliability. Football Outsiders released their DVOA rankings while we were in the throngs of playoff madness, now we take a step back to look at the defense.

Final rankings

Total defense: -15.7, third in the NFL improved from 11th in 2012

Pass defense: -15.4, third in the NFL improved from 12th in 2012

Pass rush: -16.3, sixth in the NFL, improved from 11th in 2012

There was wholesale improvement across the board, but it's curious to see that the pass rush didn't jump us quite as high as anticipated. Part of this was likely due to Charles Johnson's injury, but if there's one area we would have expected a 10 spot jump it would have been in pass rushing.

The biggest surprise comes in the secondary, which was likely largely aided by the pressure up front. Talent wise we didn't see huge shifts in 2013, and it was plausible the team could have taken a step back due to the loss of Chris Gamble, but they thrived. With an infusion of talent there's no telling how much better this unit could be.

One huge misstep was the lack of a signature cornerback to handle opposing No. 1 receivers. The Panthers ranked 16th in the league in stopping WR1, but were in the top-five in stopping second and third options. There's been a lot of buzz around getting a future offensive tackle and wide receiver, but cornerback needs to be addressed in the top few rounds if Carolina hope to build on 2013's successes.