A retrodictive resume rating built on the Colley matrix — what a team has done, not what it might do.
VRI ranks teams by accomplishment. It only knows wins, losses, and who you played — margin of victory is intentionally ignored so a team can't pad its rating by running up the score.
Every team gets one equation: rating = (1 + ½(wins − losses) + sum of opponents' ratings) / (2 + games). Solving the full linear system simultaneously gives a fair, bias-free rating that has no preseason input — only games played determine the numbers.
VRI is a 0–100 scale where 50 is "average resume." Teams with a high VRI have beaten quality opponents; teams with a low VRI either lost a lot or beat weak schedules. Because margin doesn't count, VRI tends to reward gritty wins more generously than VPPI does.
VRI answers "who deserves it?" VPPI answers "who'd win on Friday?" When the two disagree, that's usually a team riding luck (high VRI, low VPPI) or one that's better than its record (high VPPI, low VRI).