Rex Ryan is the new Jets coach. Monte Kiffin is the new University of Tennessee DC. The two have more than an address change in common.
After the first talk of a head coaching interview for Ryan, his defense surrendered a season high 391 yards to the Titans. The next week, after Ryan's interview, they did much better against the Steelers, but still gave up more yards and forced les turnovers than their season's average.
When it came out, 12 games into the season, that Kiffin was going to UT, the Bucs defense was giving up 279.5 yards per game, 95 of them on the ground. In their last four games the Bucs D gave up 386 ypg, including 189 rushing ypg. They went 0-4.
There are other explanations. In Ryan's case the Steelers and Titans were two of the best teams in the league, and naturally, with each successive playoff round, the competition is intensified. The Bucs' the losses can be pinned on Jeff Garcia's injury: Griese started the Atlanta game and Garcia struggled when he came back, throwing half of his season's interceptions in the final two losses.
The relationships here certainly aren't causal, but two very good defenses didn't play their best immediately after their respective coordinators were distracted by job offers. The correlation is worth noting.