The NFL is kind of like the NCAA. It doesn't matter if you lose to the crud teams, as long as you beat the best teams on your schedule. This means that if the top teams overlook you and you upset them, your postseason resume looks better than a team that didn't beat the best teams but also didn't lose the worst games.
So, you could beat Indy, San Diego, Cincy and New England, lose to Cle, St Louis, Seattle and KC, and that would help you.
Not to mention common opponents which is just a crazy nutty tiebreaker.
Watch this:
Say you're in the AFC South and have the following games in common with Baltimore: Oakland (both of you won), Indy (both of you lost), New England (both of you lost), Cleve (both of you won).
Who gets in?
Well, Baltimore does because they played Cle twice within the division, they won both games, and therefore have a higher %.
if you're in a division with crud teams like St. Lou or Detroit, and you sweep them, half the teams in your conference are at a disadvantage in this tiebreaker.
It's a totally preposterous and stupid tiebreaker. Words can't begin to describe how asinine it is. of all the tiebreakers, common game % is the worst.
I would change the rule so that if you beat a team twice in your division, only one of the wins counts (and vice versa for losses).