As discussed here and there in the 49ers playoff run, this 49ers team shares a lot of elements that fit in with Pete Carroll's ideas for this franchise. Strong defense, strong special teams, offense playing it safe. This is the kind of model you often see defensive-minded coaches bring in, and I think it's a big part of the reason why there are indications that defensive-minded coaches are more apt to fail, at least until they learn the value of a good offense.
The two teams built with the defense-first model lost to a much more well-balanced and well-rounded team (the Giants) and an Indianapolis Colts-like offense-only team (the Patriots). That's a shame, I was hoping for a defense-only Superbowl. The Giants-49ers game again highlighted the value of a franchise quarterback. Ravens-Patriots, oddly enough, had Joe Flacco completely outplay Tom Brady, but the Patriots still won. Conclude from that what you will.
It's pretty clear when we're talking about successful models nothing trumps getting a great or elite franchise quarterback. Even if a defensive team once again gets to the Superbowl (last one was the Bears, I guess?) all that proves is that it's possible, it's still the less likely of the two paths. Possible or likely is a distinction I personally think is worth keeping in mind.
Here is one thing I think is troublesome about this model: it is highly dependent on winning the turnover battle, and not just by a small margin. To become the championship team they were, the 49ers required a +28 turnover margin. That is not sustainable. If you depend on turnovers that badly your margin for error becomes very small, and in a single game only one or two things have to go wrong before you are effectively taken out of the game because you lack a dynamic offense.
Greg Cosell pointed this out, a very basic point so obvious I was kind of surprised it even needed pointing out:
"Now, am I going to say he's the reason they lost? No, I think that would be a little strong. But, I think in tight games like that when everything doesn't go right that's gone right for your team all year, that's when your quarterback has to make throws, and there were a few he missed. Obviously, if Kyle Williams didn't do what he did they might still have won the game.
"When your turnover differential doesn't work in a given game - and by the way, you can't count on that. It worked out phenomenally this year, but I've done studies, a lot of people have done studies, a lot smarter people than me have done studies - that kind of thing doesn't happen year after year after year. So, the +28 will not likely happen next year, and when that doesn't happen - when other things that you expect don't happen, the magnitude's of the quarterback's play increases. That's just the way the NFL is."
Let that sink in, because it's important. Depending on winning the turnover battle game after game does not strike me as a sustainable model in the modern NFL. +28 is completely unsustainable, as has been proven time and time again, as fumble luck changes and - as Cosell points out - your quarterback is asked to do more as he is needed more. The 49ers were a perfect storm of luck in this sense, but that does not make it a very attractive model to duplicate. The likelihood of this extremely small margin of error holding up for three or four playoff games is extremely small, and that - in my view - is a huge problem.