Last season, the Broncos made the playoffs but weren't a major threat with Tim Tebow under center. This season, with Peyton Manning, the Broncos went 13-3 and snagged the top seed in the AFC before Rahim Moore and the rest of their defense morphed into pumpkins against the Ravens.
Which team could take that same sort of leap next season with a quarterback upgrade? Say hello to the Arizona Cardinals.
This season, the Cardinals were one of the most unbalanced teams since 1991, according to Football Outsiders' defense-adjusted value over average metric ratings, or DVOA (click here for a detailed explanation). They finished last in offensive DVOA, at minus-31.0 percent, but their minus-13.5 percent defensive DVOA was the sixth-best in the league. Looking at recent teams with that sort of split, you'll find that regression toward the mean tends to happen. For instance, the Jaguars had the 31st-ranked offense in 2011, and improved their offensive DVOA by 8 percent in 2012. That's despite playing more than half the season with a clearly overmatched Blaine Gabbert at QB. So even if Arizona doesn't make any drastic change at the quarterback position, it's already probably going to be a little bit better on offense in 2013.