Adrian Peterson, Vikings among Super Bowl sleepers

Everyone remembers the powerhouse Super Bowl champions -- the 1970s Pittsburgh Steelers, the 1980s San Francisco 49ers, the 1990s Dallas Cowboys. As fun as those team were to watch, it's worth remembering the NFL has had its fair share of surprise champions over the years: the 1980 Oakland Raiders, 1981 San Francisco 49ers, 1999 St. Louis Rams and 2001 New England Patriots.

The NFL does not appear to be in the midst of a true dynasty -- sorry, Seahawks fans -- so who could come out of nowhere to win the Super Bowl? Three teams fit the bill.

(Note: The passing game metrics listed below include yards gained on penalties such as defensive pass interference and illegal contact.)

Minnesota Vikings

The last five years have possibly been the nadir of the Vikings franchise, as they've finished under .500 four times, which had never happened in any other such span in team history.

This all looks poised to change, as multiple signs point toward the Vikings becoming one of the NFL's up-and-coming teams.