The committee will release new rankings every week until Dec. 4, when its final rankings will determine the pairings for the national semifinals. Those games — the Fiesta Bowl, in Glendale, Ariz., and the Peach Bowl, in Atlanta — will be held Dec. 31. The winners will go to the national title game on Jan. 11 in Tampa, Fla.

The 12-member committee will also help determine the composition of the four other playoff-affiliated bowl games, although conference commitments play a part; for instance, the Rose Bowl will pit a Big Ten team against a Pac-12 team.

The highest-ranked champion from the second-tier conferences, collectively known as the Group of Five, will play in the Cotton Bowl in Arlington, Tex., on Jan. 2. At No. 23, Western Michigan (9-0), of the Mid-American Conference, remained in line for that spot with a 52-20 win over Ball State on Tuesday; Boise State (7-1), of the Mountain West, is one place back in the rankings.

The Big 12, which placed no members in the playoff in 2014 and is the only major conference that does not stage a league championship game, is in a deep hole. No. 17 Baylor (6-1), No. 18 Oklahoma State (6-2) and No. 20 West Virginia (6-1) have had weak out-of-conference schedules, and Oklahoma has lost to Houston, which was not included in the rankings, and to No. 6 Ohio State.

There is a good case to be made that if Alabama, Clemson, Michigan and Washington win the remainder of their games, they will fill the four spots in the final bracket. Washington would be 13-0 while Texas A&M could at best finish 11-1. (The Aggies would be blocked from playing in the SEC championship game by Alabama, which also plays in the conference’s West division.)

Four 13-0 major conference champions would be unprecedented in the playoff era, though, and challenges remain. Alabama plays at No. 13 Louisiana State (6-2) this weekend and hosts No. 9 Auburn on Nov. 26. Texas A&M also has L.S.U. remaining on its slate.

In a throwback, the most eagerly awaited regular-season game remains Michigan’s trip to Ohio State on Nov. 26. The winner is likely to face another current top-10 team — Wisconsin or Nebraska — for the Big Ten title.