For our entire lives as football fans, it's been drilled into our heads that defense is what wins in football. Some of the great cliches in the sport revolve around having a stout defense.
However, when you take a look at the bottom of the team defensive rankings for 2011, you will find arguably the three best teams in football.
Last season, the Giants, Patriots and Packers ranked 27th, 31st and 32nd respectively in team defense. The Saints, who were the darlings of the NFL playoffs before being bounced by the 49ers, were ranked 24th.
The NFL may be a copycat league, but don't expect teams to copy the blueprint of having absolutely no defense.
Despite the success of teams with less-than-stellar defenses in 2011, more teams tend to build from the defense up.
A number of teams have made changes through free agency, the draft or by changing coordinators. This slideshow examines the teams whose defenses will take the biggest leaps forward in 2012.