re: What is the worse case scenario for Bama?

If auburn beats Bama, it doesn't matter if they win out - the winner of the SEC title game would get in ahead of Bama, the loser would not get in. The winner of Miami/Clemson gets in ahead of Bama. So worst case scenario is losing to auburn and having Oklahoma and Wisconsin win out. That would probably keep Bama out of the playoffs.

It gets closer and more interesting if Bama beats auburn and loses to UGA in the SECC. I still think the above would play out, though, but it's a tighter discussion.