Everybody loves a good underdog story. The less likely the odds, the better.
There haven't been any huge upsets so far this NFL season, but there's plenty of time for that to change. A struggling team such as the Miami Dolphins or Washington Redskins could get rolling one Sunday and knock off a top team, potentially impacting the hunt for playoff spots down the line.
As a bettor, it's important to guess right about potential upsets, as choosing a favorite to cover the spread then watching it get knocked off by a lesser underdog can be devastating.