Former BCS computers rank Alabama No. 1, Ohio State in top four

College football's last week of the regular season resulted in another first: Alabama is No. 1 in the College Football Computer Composite, the weekly ranking formulated by the former Bowl Championship Series computers.

Alabama ranked No. 1 in three of the five computer formulas that make up the CFCC and was No. 2 and No. 4 in the others.

Clemson dropped to No. 2 after four weeks in the top spot, and sits just half a place ahead of No. 3 Oklahoma. And just as notable, Ohio State rose three spots to No. 4 on the strength of a dominant win against Michigan, which entered the week at No. 12 in the CFCC.

Clemson and Iowa were No. 1 in the formulas that did not have Alabama as the top team.

The College Football Computer Composite combines five of the computer formulas used in the former Bowl Championship Series standings to remove the human element from college football rankings. The computer rankings accounted for one-third of the final BCS rankings, with the Harris and Coaches polls comprising the other two-thirds.

The CFCC is compiled by taking the geometric mean of rankings formulated by Richard Billingsley, Wes Colley, Ken Massey, Jeff Sagarin and Peter Wolfe. Among the metrics feeding the CFCC are wins and losses, strength of schedule, home-field advantage, recency of game and, in Massey and Sagarin's case, margin of victory.

College Football Playoff scenarios for the remaining contenders

The team with the biggest rise this week is Southern Miss, which is up 15 spots after beating Louisiana Tech 58-24 and clinching a berth in the Conference USA championship game.

The team with the biggest decline was Air Force, which one week after clinching a berth in the Mountain West championship game fell 19 spots thanks to a 46-35 loss at New Mexico.

Updated CFCC rankings are published each week during the season on FootballFour.com. You can find every weekly ranking for 2015 here. This week's complete ranking of all 128 FBS teams is below.