VPPI · Virginia Predictive Power Index

Purpose

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.

Inputs

• Final score margins for every completed game (capped to limit blowout inflation).
• Location adjustment for home / away / neutral.
• Recursive opponent strength — wins over strong teams pull a rating up; losses to weak teams push it down.
• Recency weighting so late-season form matters more than Week 1.

Calculation

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.

How to read it

• 100+ — elite, state-title contender.
• 80–100 — strong playoff team.
• 60–80 — competitive, mid-tier.
• < 60 — rebuilding / lower division.

A 10-point VPPI gap ≈ a one-score favorite. A 20-point gap ≈ a near-certain win.

VPPI vs VRI

VPPI is predictive — it tries to be right about next week. VRI is retrodictive — it ranks teams strictly by what they've already accomplished. Use VPPI to pick games, VRI to argue about resumes.