No, more often than not, defense still wins championships. Yea, if you have a top offense it is possible to win with a below average defense, but it doesn't happen as often as the other way around (great D with an average O).
Aside from the 2000 Ravens, how many teams had a really bad offense?
I read somewhere since 1970 something 34 of the SB winners were in the top 10 in D and 29 were in the top 10 in O. Not too surprising to find good teams are good on both sides of the ball.
ETA: Check out a bood called Scorecasting, it kinda like Freakonomics but about sports. Anyway it talks about this for all sports, not just FB.
I do agree with whoever said its easier to build a good D, than to get an elite QB. Just look at the Texans this year, from worst D in the league to one of the best.
This post was edited on 12/8 at 10:51 am