Notre Dame (.9396) is third, not too far behind, but most likely in need of a loss by Oregon or Kansas State to reach the title game on Jan. 7 in Miami.
"These teams are in their order and the only way that order changes is if somebody gets beat," said Jerry Palm, of CBS Sports and collegebcs.com.
As for Alabama's run at three championships in four seasons, and the Southeastern Conference's string of six straight BCS titles, both are in peril.
Kansas State is second in both BCS polls - the coaches' and Harris - and in the computer rankings. The Wildcats have two games left, at Baylor on Saturday and home against Texas on Dec. 1, the day of most of the conference championship games.
Oregon is first in the both polls and fourth in the computer ratings. The Ducks have two more regular-season games left, against Stanford on Saturday and the next week at Oregon State. They can clinch the Pac-12 North and a spot in the conference title game with a win against Stanford. If they get there, the Ducks would play either UCLA or Southern California in the league title game.
If the Ducks and Wildcats can avoid the type of upset that dropped Alabama - and there are plenty of good teams left on their schedules - they will play for the national title.
The Fighting Irish are third in the polls and first in the computer ratings.
"Notre Dame is not going to jump (Oregon and Kansas State) without their help," Palm said. "They're way too far behind in the polls. The voters are not on board with Notre Dame."
Alabama (or Georgia or Florida, which could also both win the SEC with just one loss) needs two of the top three to lose to get to the title game no matter how it finishes.