One calculation across every scored game in Mississippi, MHSAA and MAIS, 1A to 7A, to say how good each team is, what it has done, and what to expect on Friday.
Two numbers per team
The PCPI says how good a team is: how many points better or worse than an average Mississippi team. It's one least-squares fit of every scored game at once, so beating a good team counts for more than beating a weak one.
The résumé says what a team has done: the chance that a top-10% team would match its record against that exact schedule at those sites. Wins and losses only. Petal and Bruce are both 6–0; Petal's schedule puts its résumé 2nd, Bruce's puts it 66th. The Top 25 is ranked by résumé, with the PCPI beside it.
When the two disagree
That's the story. Gulfport is 2nd in the PCPI and 31st in the résumé: it lost 40–39 at Petal and won its other four by 34 or more. Petal is 2nd in the résumé and 19th in the PCPI: six wins, three of them by four points or fewer.
Friday's number
Each game gets a projected margin and a win chance from the ratings of the week before ("Caledonia by 23 · 95%"). A margin that rounds to zero is a toss-up. The side given under 50% that wins is an upset.
The win chance widens when the ratings know little about a team: the typical miss is about 22 points before a first game, narrowing to about 14 by Week 5. That's why a chance rarely reads above the mid-80s early on. Each week's numbers are set before its games and never revised, so they're the numbers we're measured against.
What counts
Every game with a result we can stand behind: confirmed, ruled by the Press Coverage team, or from our archive back to 2015. A disputed game stays out until it's settled. Forfeits count in the record and the résumé but not the rating, since there's no score. Jamborees and scrimmages don't count.
Built from measured parts
- Margin cap
- 35 points, the handbook's running-clock line. Running up a score buys nothing.
- Starting point
- 90% of last season's final rating, worth one game. It fades as games pile up; it's what makes the early weeks usable.
- Home field
- Fitted from the season's results every week: about 2 points (1.8 after Week 6); 1.0 to 1.9 in 2015–2025. A disputed host plays as neutral.
- Class step
- +2 points per MHSAA class, measured from ten seasons (the bigger school beat expectation by about 1.9, 3.2 and 4.3 points at one, two and three steps). Only between two MHSAA teams; MAIS games carry no step.
- This season's fit
- 869 games, 371 teams (11-man) after Week 6: the 267 we rank (225 MHSAA, 42 MAIS) and 104 opponents, 90 from out of state, kept so those games count. 8-man is its own fit: 40 teams.
The weekly rhythm
Ratings are rebuilt after each week's games. Each Sunday night the week's numbers are set: from then on its ratings, ranks and projections never move. A late correction reaches the next week, never a set one. Scores and records always follow the latest confirmed result.
How right it is
82% of winners called from Week 4 on, and about 70% in Weeks 1 to 3, backtested on 2016–2025 using only earlier games.
The win-loss formulas Georgia, Louisiana and Oregon use, in our own backtest on the same Mississippi games, land at 71 to 72%. This season: 76%, 72%, 78% and 83% in Weeks 1 to 4.