The USA Today Expert rankings of high school football teams in the United States are decided by members of the USA sportswriting staff, and are based on the teams' record, final results and quality of players. USA Today Computer rankings are calculated from a methodology invented by statistician Ken Massey, which takes numerous specific factors into account.
USA Today's Expert top 25 is based solely on the judgment of the people creating the rankings. Initial season rankings are based on the recent success of a high school football program, key players and predicted results. While the rankings consider these aspects as a way to rank some programs over others, there are no objective methods of choosing the Expert rankings.
The Computer top 25 is a systematic, repeatable method of putting specific factors into a model and calculating rankings. Massey's computer model takes into account weighted game results depending on home and away games, overall strength of competition and record over time. According to USA Today, the Massey computer rankings are intended to objectively quantify a hierarchy of high school sport programs, and the system becomes more accurate as the season goes on and the computed sample size increases.
Because of the different methodologies employed by the two separate USA Today rankings, the results tend to differ between the two frequently.