This infographic is the first in a series I'll be producing throughout the off-season at my blog, BCF Toys. Comments and suggestions for future infographics are welcomed.
In 1989, there were 106 Division 1A (now called FBS) teams. A total of 582 games were played between those teams, including 18 bowl games. 52 of the total games (8.9 percent, or about 1 in 11) were played between teams ranked in the Associated Press final top-25.
In 2009, 120 FBS teams played a total of 714 games against one another, including 34 bowl games. Only 38 of the total games (5.3 percent, or about 1 in 20) were played between Associated Press final top-25 teams.
The AP final top-25 was significantly more connected in 1989 than 2009. Only nine ranked teams played at least four games against other ranked teams last season; in 1989, 18 ranked teams did so. Twenty years ago, the AP top-10 either played or shared a common opponent with an average of 17 other ranked teams. In 2009, the AP top-10 either played or shared a common opponent with an average of only 12.6 other ranked teams.
In twenty years, the frequency of games played between top-25 teams has been nearly cut in half. The primary reason for the decline has been conference expansion. In 1989, 25 teams were independent, including AP final Nos. 1, 2 and 3 and six of the top-25 overall. In 2009, only 3 FBS teams were independent, none of which were ranked. Additionally, there were 94 FBS vs. FCS games played last year, 17 involving AP top-25 teams. Only 50 such games were played in 1989, two by AP top-25 teams.
With Stanford's upset over Notre Dame and Ohio State's big win over rival Michigan in The Game, the playoff field has narrowed to the existing top four plus Michigan State, Ohio State, Stanford, and potentially North Carolina.