Data is posted through games of 9/20. A few statistics such as net punting/punt return, net kickoff/kickoff return, and fourth down conversions are not yet connected. Data is free for all to use, but if you use it please reference this site as the source and if you include a link, point it to the main page.
Beginning in 2000, 1-A/FBS teams are included in the ratings. Prior to 2000 I include all teams that played a reasonable number of games against other teams. That number changes based on the average number of games played by teams in that season. Only games between the rated teams are considered with the following exception:
1943 - The rated teams were not connected and therefore ratings were run using all games.
Adjusted stats are available for the 2000-2014 seasons, please see information on the ABOUT link.
I hope to soon begin work on a new site layout but there is no ETA on that.