Better Know A BCS Computer: Colley Matrix

in Computer Polls by Asher Feldman — August 1, 2010 at 3:27 pm | 1 comment

[Editor's note: In August of 2010, BCS Know How took a look at each of the six BCS computers using all available information and a multitude of sources. Some formulas are more public than others. I aimed to make the most inclusive collection of facts about all of the computers, with a varying degree of success.]

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Let’s take a closer look at the Colley Matrix.

Before we begin, the highly-regarded Burnt Orange Nation took a close look at Colley’s formula in 2006, as part of their series on the BCS computers, so check that out for some background information. The post title is literally coincidence… but I guess there’s only so much you could call a series about BCS computers.

But I digress. Colley claims to run a “bias-free” ranking system, taking no prior performance or personal opinion into account. At the beginning of the season, each of the 120 FBS football teams start on equal ground, so early polls are often unusually different from the human element polls such as the AP, Coaches and Harris Interactive Polls.

Colley relies heavily on strength of schedule to rank his teams. However, the Matrix disregards home-field advantage in any matchup, meaning that all games are weighed equally irrespective of their location.

Colley’s strong reliance on strength of schedule easily allows for three- and four-loss teams to easily rank ahead of two- and one-loss squads throughout the year, and even in final season rankings. The Matrix also does not credit teams for running up the score, as Colley believes increased score margins only act to influence human voters and adds bias to rankings.

In conclusion, Colley (a PhD recipient in astrophysical sciences from Princeton) believes his rankings achieve the following as a part of his computer ranking formula:

1. It has no bias toward conference, tradition, history, or prognostication.
2. It is reproducible; one can check the results.
3. It uses a minimum of assumptions.
4. It uses no ad hoc adjustments.
5. It nonetheless adjusts for strength of schedule.
6. It ignores runaway scores.
7. It produces common sense results that compare well to the press polls.

To check out more from Wes Colley, visit his rankings homepage HERE.

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