The formula
Basic model
Dominance, 20% -- number of national championships
Peak strength, 20% -- winning percentage for best 50 seasons in program history
Since integration, 30% -- winning percentage over the past 50 seasons (1969-2018)
Early modern, 20% -- winning percentage over the middle 50 seasons (1919-1968). Mostly pre-integration and included some games against non-college teams
Pre-modern, 10% -- winning percentage over the first 50 seasons (1869-1918) *mostly pre-standardization of current rules and many games against non-college teams
Adjustments
National championships below the FBS level count at 50%
National championships before the poll era (1936) count at 50%
Winning percentages when a team was not in Division I are reduced by 10%