The Super Bowl has hosted some of the best games in NFL history. Upsets are not as common as one might think, however, as just 15 Super Bowl underdogs have been crowned as champs.

And 15 of 46 is 32.6 percent. Hardly good odds if your favorite team comes into Super Bowl week as a ‘dog.

However, three of the past four Super Bowl champions came in as underdogs. That could mean one of two things: either Vegas is losing its mind, or the NFL has more parity.

Bet on the latter.

Super Bowl games deemed un-winnable for a team have been unkind to many contenders. But these five ‘dogs laughed in the face of naysayers to hoist the mother of all trophies.

Here are the five biggest Super Bowl upsets in NFL history.