Alabama and South Carolina will not play for the National Title, one of them will elimate the other. If Alabama loses that game, their strength of schedule will hold them back since the only ranked team they will play is Mississippi State and LSU up till the SEC title game.
Oregon will more than likely go undefeated so that will also elimate a second SEC team. Then if you have an undefeated Big12 team, WVU or KState, their SOS will proably make them leapfrog someone. WVU has already beaten the #25 and #11 when they were ranked at that point, and KState has beaten #4 OU. If KState and WVU win this weekend, you will probably have 4 play 5 (more likely 6). Whoever wins that game will probably leapfrog in the rankings based on the rankings of each team making them #3.