Football - Rankings
Division I-A College Football Rankings
About the Rankings
Since the advent of the Bowl Championship Series (BCS), computer rankings have played a prominent role in determining college football's national champion. Ranking 120 teams using a handful of games involving each is extremely difficult and inherently ill-defined. Many ranking methods are based solely on wins and losses. Others are based on point-scoring and margin of victory. Which are better?
Both types of models are problematic for ranking college football. Win-loss models often predict that undefeated teams (even those who played a very weak schedule) will never lose and are infinitely better than even the best one-loss teams. This results in the Ohio State1 effect (determining the only undefeated team is, de facto, the best around). At the other extreme, point-scoring models discount the value of winning and can rank a mediocre team with a few blowouts ahead of a solid, yet unspectacular team with a better record against a tougher schedule. (We refer to this as the Kansas State2 effect.)
Our rankings are the first to combine both wins and losses AND point-scoring data to extract the most from a limited slate of games. In addition to modeling win-loss and point-scoring data, our rankings explicitly account for home-field advantage and implicitly consider strength of schedule. Rather than rehash the details here, we refer the curious to Annis and Craig (2005)3 for in-depth explanation of the ranking procedure.
You will find our Strength-of-Schedule ratings here.
Our rankings were mentioned in the Kansas City Star (November 18, 2005) and the Charlotte Observer (October 18, 2006 and October 17, 2007).
- In the 2002-2003 season, Ohio State won the national championship after completing the only undefeated season in Division I-A. Despite their 14-0 record, the Buckeyes had seven wins by a touchdown or less, including a 10-6 win we saw in person at Purdue. I'll go to my grave thinking that they were much more lucky than good.
- Under Head Coach Bill Snyder, Kansas State has earned a reputation as a team which schedules extremely weak non-conference opponents, resulting in many season-opening blowouts, and consequently, impressive scoring margins ... even for a three-loss team.
- Annis, D. H. and Craig, B. A. (2005) "Hybrid Paired Comparison Analysis, with Applications to the Ranking of College Football Teams." Journal of Quantitative Analysis in Sports, 1 (1).