A predictive rating designed to forecast future game outcomes, not reward past results.
Using a version of a Massey Matrix, VPPI estimates a team's true strength on a single scale. Two teams' VPPI difference translates directly into a projected scoring margin and win probability, making it the primary engine behind the Matchup tool and weekly excitement scores.
Ratings are solved iteratively: each team's VPPI is set so that its predicted margin against every opponent matches its actual capped margin, weighted by recency. The system converges in a few hundred passes and is re-solved every week against the full season-to-date.
VPPI is predictive; it tries to be right about next week. VRI is retrodictive; it evaluates teams strictly by what they've accomplished. Use VPPI to pick games, VRI to argue about resumes.