Lost in the shuffle of coaching rumors and talk of unrest between Sean Payton in the front office, the Saints must still choose a defensive coordinator for 2016. There hasn't been much talk of whether or not Dennis Allen will be replaced, but it is a question that warrants exploring.
First of all, how did Allen do? Allen was brought on in the 2015 offseason, and was obviously to relieve Rob Ryan if Ryan's defense continued to underperform as it did in 2014. Known as a secondary coach, Allen had only one brief stint as a defensive coordinator prior to 2015, in 2011 with the Broncos.
In Rob Ryan's time with the Saints in 2015, opposing quarterbacks were 232/348 (67%) for 3,081 yards (308.1 YPG) and 28 TDs (including 14 in the last 3 games). Meanwhile, against Dennis Allen's defense, opposing QBs were 140/196 (71%) for 1,674 yards (279 YPG) and 17 TDs. Notably, in one less game, Dennis Allen's defense had one more interception (5) than Rob Ryan's at 4.
Now, all of these numbers mean what the person construing them wants them mean. The fact is that, despite some turnover in the secondary and up front, both coordinators were working with largely the same defense. Whether the shortcomings were their own or their personnel's, the fire will always land on the DC. The Saints' unit, however, was young and undisciplined barring a few notable exceptions. A unit that is starting 5 rookies by the end of the season is going to have some growing pains.
The real issue lies in a total inability to adjust. Brandon Browner was a prime example. His play itself has been talked about to death, but the Saints signed a player with no real knowledge of how to use him. When Browner was first signed, I wrote an article about how he could jam up receivers at the line and play physical ball that Saints' corners simply weren't playing. That... Didn't happen. Instead, they consistently had Browner give up cushion, and he didn't have the closing speed to keep up with slants or Go routes when he was playing 6 yards off. His physicality was his strength, and it was never exploited, and when it wasn't working he just kept playing rather than being taken out.
The front 7, meanwhile, was bland and uninspired. conceding that defensive line and pass rush isn't Allen's forte, it was still Cam Jordan against the world. Hau'oli Kikaha was used frequently in coverage rather than pass rushing, which is his biggest strength, and Stephone Anthony barely improved in coverage throughout the season. It's going to continue to be the DC's job to develop linebackers for the Saints as long as Joe Vitt is in charge of the unit, and the Saints' 31st overall and second round picks are running a serious risk of being squandered.
Dennis Allen shouldn't be the future of the Saints' defense. He is more of the same, and it showed when he took over. Perhaps with a full offseason to develop his scheme and implement it, some change could occur, but that runs a huge risk for the Saints' organization, especially in Drew Brees's waning years. Brees is still playing out of his mind, but no one should expect that to go on forever.
If the Saints really want a top flight DC, unfortunately, it would have to be in the form of a new head coach. Teryl Austin would fit the bill. His defense regressed this year from 2014, but it was also without his prime talent Deandre Levy.
Let's assume that Sean Payton is going to stay, because he is. Defensive coordinator will likely be a converted position coach or a college DC. Minnesota linebacker coach Mike Zimmer could be a strong option if he were to leave his dad's tutelage, and Joe Whitt Jr. of Green Bay's secondary could be frontrunners. Both coaches have done good things with their respective units, but the latter could really help where the Saints are weak.
All in all, Sean Payton needs to ask what he's looking for in his defense. The draft finally addressed it, something rarely done in the Payton-Loomis era, but now the coaching mentality has to do so as well. If the Saints really are serious about winning again in the near future, it starts with this decision.