Super Bowl betting began with a couple of blowout wins by the Green Bay Packers for easy payouts with the NFL odds.
But in January of 1969 the New York Jets stunned the entire Super Bowl betting world with their unforgettable 16-7 win over the Baltimore Colts as 18-point dogs with the NFL odds to forever change the perception of the game and its possibilities.
In recent years there have been plenty of stunning upsets with the NFL odds. In February of 2008 the New York Giants pulled off an upset that was as memorable as that of the Jets when they ruined the New England Patriots undefeated season in a 17-14 win as 14-point dogs.
The Patriots themselves pulled off an epic upset win in February of 2002 when they scored a 20-17 win over the St. Louis Rams as 14-point dogs.
The Denver Broncos were 11-point dogs against the Green Bay Packers in January of 1998 and given virtually no chance in their 31-24 win.
The history of the Super Bowl betting is now old enough where nothing should be too surprising or shocking and the aforementioned upsets of recent years demonstrates that there are no sure things in the biggest of the big games.