Denver, Oakland, SD finished 8-8, all of them are 3-3 in the divison games, SD is 7-5 in conference games, but Denver is only 6-6. Why did Denver win the Division?

Also, Cincy and Tenn finished 9-7, Tenn has better conference record 7-5, but Cincy gets the Wildcard. 

I don't understand why.