FCS Grouping System
The Colley Matrix system, as applied to college football from 2001 to 2006,
did not account for FCS teams whatsoever. This stance was based upon the
idea that good FBS teams who might be of relevance to the BCS should not
lose to FCS teams, and as such, FCS could be rightly ignored.
However, 2006 saw the expansion of the schedule from 11 games to 12 games.
In response to this addition of a 12th game, many FBS teams have
added FCS teams to their schedules. The significantly higher number
of FBS vs. FCS games has created three problems for the complete
exclusion of FCS results. First, a larger fraction of results are
ignored. Second, the increased competition between the two divisions
has increased the parity between them, making FCS victories more likely.
Third, the larger number of games makes the previously "flukish" win by
a FCS more likely, just statistically. These three issues demand that
a good ranking system for FBS somehow account for the games against FCS.
The Colley Matrix has addressed this problem in a straight-forward way
that does not change the fundamental mathematics of the Colley Matrix
rankings system. Here is how it works.
- Selecting only games involving two FCS teams, rank the FCS teams
using the normal Colley Matrix system.
- Form groups of FCS teams.
We now have groups of FCS teams that have played about the same
number of games against FBS as most FBS teams have played this season.
Add these groups into the list of FBS teams.
Rank the FBS teams plus the FCS groups as normal with the Colley
Matrix ranking system.
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Wesley N. Colley
- Determine the average number of games played by FBS teams.
- Starting at the top of the ranked list of FCS teams, begin
adding to the group until the number of games that group has
played against FBS is about the same number of games most FBS teams
have played so far this season.
- When the group is "full," move to the next group and repeat
- Avoid the problem that the last group may be underpopulated by
iteratively "demoting" teams from other groups until the distribution
of FBS games played by each FCS group is fairly even.