Lets say Big 10 goes chalk from here on out, and Ohio State beats Indiana by 21. So while Indiana would be 11-1, their best win is Michigan, Michigan State, Nebraska, UCLA or Washington. Who cares, you pick. They're all 6-6. Indiana won't have a win against a team with a winning record in this scenario.
How can you give an at large berth to a team that does not have a victory against a team with a winning record, and was completely blown out by the only good team it played?