SRS ratings
The Simple Rating System (SRS) measures team strength from scoring margin after adjusting for schedule strength and home field. It evaluates the network of game results together so that performance against a strong opponent is not treated the same as an identical margin against a weak opponent.
Higher values indicate stronger performance. A rating of 8.0 can be read as
roughly eight points better than the average FBS team on a neutral field within
that season's rating system.
How it works
SRS starts with adjusted scoring margins from completed FBS and FCS games. It then solves for the set of team ratings that best reconciles each team's results with the strength of its opponents. Extreme scoring margins are limited so that one unusual game does not dominate the season estimate, and the final FBS ratings are centered around zero.
This is a season-to-date descriptive rating. It is not a win probability and does not separately rate offense, defense, or special teams.
CFBD SRS is proprietary. Exact margin limits, home-field values, and full calculation details are not published.
Standard and expanded SRS
The standard endpoint returns FBS team ratings. The expanded endpoint includes additional classifications where ratings are available, which can be useful for analyses involving FCS opponents.
rating contains the point-based SRS value. ranking is the team's ordered
position when teams are sorted from highest to lowest rating; it is not an
additional model output.
Limits to keep in mind
Early-season SRS can be unstable because the schedule network contains fewer games and less cross-team information. Ratings become more connected as the season progresses, but they still summarize the games played rather than projecting a specific future matchup.
Comparisons are most meaningful within the same season and endpoint scope.