First, a quick summary of the rankings. I rank college football teams using a Bayesian hierarchical model that incorporates margin of victory. The pre-season rankings serve as the prior distribution for the model and are a combination of “expert” opinions about the relative strength of teams before the season starts (specifically, the pre-season rankings from Yahoo, Athlon and Lindy’s). I update the model every Sunday once new results are available. Using the updated model, I simulate the remainder of the season 10,000 times, which allows me to estimate a team’s expected final record, probability of winning all of their remaining games, etc. I will provide a more detailed description of the model and simulation on my methodology page for those that are interested.
The pre-season rankings are simply a combination of published pre-season rankings and reflect the general consensus going into the season. Alabama is the unanimous number 1, followed by Ohio State, Boise State, Florida, Texas, Nebraska, Oklahoma, USC, Virginia Tech and Oregon. I have two quick comments on the top ten. First, the Oregon Ducks made weekly appearances in the police blotter during the offseason (although, none were as strange as the recent arrest of an offensive lineman at rival Oregon State) and, depending on when the rankings I used for the prior were published, the pre-season rankings may not reflect that quarterback Jeremiah Masoli was dismissed from the team. Oregon is still a contender for the Pac 10 title but losing Masoli will hurt. Second, USC had a tumultuous offseason culminating in being placed on probation for the Reggie Bush fiasco. The Trojans are not bowl eligible and can’t receive votes in the Coaches Poll but they still look like the strongest team on the West Coast.
Here are the top 15 teams ranked by the probability that they go undefeated:
P(WARG) = probability of winning all remaining games
One of the most interesting storylines of the season is Boise State’s quest for a national title. They are a legitimately elite team but, more importantly, their schedule is much weaker than the other national title contenders. They will have an excellent chance of running the table if they defeat Virginia Tech on Monday night. TCU is in a similar position to Boise State but probably starts the season ranked too low to have a legitimate shot at the national title. The title contenders from BCS conferences have a much tougher road to the national title. Even as the unanimous number 1, Alabama only has a 6.5% chance of going undefeated. Ohio State has the best chance of the BCS crowd but still only has a 13% chance of going undefeated. Finally, I’d be remiss if I didn’t discuss the #3 team on this list: Navy. The Midshipmen have had a great run over the last few years and are expected to be a solid, top-30 caliber football team. Their schedule is incredibly weak and they have a very real shot at going undefeated. Can they make the BCS? We’ll see? It would be a great story for sure.
Have a good one. I can’t wait until kickoff!