St. Mary's Academy and the 2026 6A girls playoffs
The two rankings
Left: the OSAA rank. Right: Model B, a rating that counts goal margin and strength of schedule.
Every Model B rank, bracket and probability on this page uses the head-start version, the one the protocol scores first; the head start is last season's OSAA standing. So far this season the head start has made no measurable difference to accuracy.
The OSAA has St. Mary's Academy 36th in 6A. Model B has St. Mary's Academy 28th with last season's standing as a head start and 29th without it. St. Mary's Academy is out of the field as posted. Under the same rule with Model B's order, St. Mary's Academy is in and Sprague is out, with or without the head start. Nelson (OSAA 19th) is not in the posted field; the OSAA's page gives no reason. Sprague (OSAA 33rd) is in instead, and this page holds that fixed, as it holds the automatic bids fixed.
St. Mary's Academy's season
St. Mary's Academy finished 3–8–3, 0–5–1 in league. Against 6A teams in the OSAA's top 32 it went 0–8–1, 5–19 on goals; the five games against the top 16 went 0–5, 3–12. Against everyone else it went 3–0–2, 12–3: 1–1 vs. Wilsonville (#19 in 5A), 4–1 vs. Aloha (#31 in 5A), 4–0 at Newberg (#38), 3–1 vs. Century (#41) and 0–0 at Oregon City (#37). What lifts St. Mary's Academy under Model B is the margins: 3–12 over the five games against the top 16, against 12–3 in the five games against teams outside the top 32.
| Date | Type | Opponent | Opponent's OSAA rank | Result |
|---|---|---|---|---|
| 09/01 | Non-league | Wilsonville | #19 in 5A | 1–1 D |
| 09/08 | Non-league | Nelson (away) | #19 | 1–2 L |
| 09/14 | Non-league | Aloha | #31 in 5A | 4–1 W |
| 09/16 | Non-league | Sunset (away) | #10 | 1–3 L |
| 09/18 | Non-league | McDaniel (away) | #15 | 1–2 L |
| 09/22 | Non-league | Newberg (away) | #38 | 4–0 W |
| 09/24 | Non-league | Forest Grove | #30 | 0–0 D |
| 09/29 | Non-league | Century | #41 | 3–1 W |
| 10/01 | League | Oregon City (away) | #37 | 0–0 D |
| 10/06 | League | Lakeridge | #8 | 0–3 L |
| 10/08 | League | Tigard (away) | #9 | 0–1 L |
| 10/13 | League | Lake Oswego | #18 | 1–4 L |
| 10/20 | League | West Linn | #12 | 1–3 L |
| 10/22 | League | Tualatin (away) | #21 | 0–1 L |
The field as posted
The 6A bracket has 24 places. Seven automatic qualifiers, one per league, and nine at-large teams by OSAA rank go straight in; the next sixteen by rank play a qualification round for the last eight places, so 32 teams are in contention.
| Qualification round, Oct. 27 | Home | Draw | Away | |
|---|---|---|---|---|
| #16 Sprague at #1 Westview | 92% | 5% | 3% | |
| #15 Glencoe at #2 Cleveland | 78% | 13% | 10% | |
| #14 Ida B. Wells at #3 Lake Oswego | 73% | 15% | 12% | |
| #13 Forest Grove at #4 North Medford | 67% | 18% | 16% | |
| #12 South Salem at #5 Tualatin | 80% | 11% | 8% | |
| #11 Beaverton at #6 Franklin | 48% | 23% | 29% | |
| #10 David Douglas at #7 Sherwood | 65% | 19% | 17% | |
| #9 Sheldon at #8 Clackamas | 28% | 23% | 48% |
Probabilities are Model B's, head-start version, calibrated on its own predictions this season, rounded to the nearest point.
The Model B bracket
Same rule, same 7 automatic qualifiers, Model B's order everywhere the OSAA's is used. St. Mary's Academy is the 12th seed of the qualification round. With or without the head start, St. Mary's Academy replaces Sprague. Pairings follow seed order, 1 against 16. The OSAA makes up to two moves of the lower-ranked team to avoid a same-league game, and this page applies the same rule; it moved Roseburg and Sherwood. The higher seed hosts. Sherwood, the author's school, is also in the Model B round; it is OSAA 24th and Model B 26th either way.
| Qualification round | Home | Draw | Away | |
|---|---|---|---|---|
| #16 South Salem at #1 McDaniel | 84% | 9% | 6% | |
| #15 David Douglas at #2 Cleveland | 80% | 12% | 9% | |
| #14 Glencoe at #3 Tualatin | 74% | 14% | 11% | |
| #13 Forest Grove at #4 Barlow | 73% | 15% | 12% | |
| #12 St. Mary's Acad. at #5 Franklin | 65% | 18% | 16% | |
| #11 Clackamas at #6 Sheldon | 64% | 19% | 17% | |
| #10 Roseburg at #7 Beaverton | 53% | 22% | 25% | |
| #9 Sherwood at #8 North Medford | 51% | 23% | 26% |
How Model B works
The OSAA ranks teams by averaging two formulas, RPI and Colley. Both use wins, losses and draws, weighted by opponents' records, and neither looks at the score. The NCAA stopped ranking men's basketball this way in 2018, when it replaced the RPI with the NET, which counts scoring margin capped at 10 points. Two high-school associations already seed soccer with margin: the CIF Southern Section, the largest of California's ten sections with more than 550 schools, by Massey Ratings, built by Kenneth Massey, whose college football rankings were one of the BCS's six computer polls from 1999 to 2013; and the MIAA in Massachusetts, since fall 2021, by a rating on goal margin capped at three goals a game.
Model B is built the same way as Massey's rating. Each game's goal margin is treated as the difference between two team strengths plus a home-field term, and the strengths that best explain every game of the season are solved for together. Last season's standing seeds the rating in August and fades as games accumulate. Margin is not capped, because the OSAA already ends a match at an eight-goal difference from halftime on. The settings were chosen on past seasons and fixed on September 30, five weeks into this one, before any playoff game.
It matches the ratings Massachusetts and the Southern Section use. On the Southern Section's 261 boys' playoff games last season, Model B and the official Massey rating are equal to the third decimal on log-loss, 0.921 to 0.920, with an error bar of about plus or minus 0.05; on the girls' 225 games Model B is ahead of the official rating by about 0.05, with an error bar that just clears zero. Both use playoff games only, because the section posts Massey ratings only at its seeding lock. On four regular seasons of Massachusetts games, both sexes, Model B is ahead of the MIAA's rating by two to three hundredths of log-loss under the settings fixed on September 30, 2026; under the earlier settings it tied for boys and trailed for girls.
It calls more games right than results-only rankings. Rebuilt from the OSAA's own pages for the twelve boys' seasons since 2013, Model B calls 66 of 100 6A games right to the OSAA rank's 64, ahead in all twelve seasons; across 6A, 5A and 4A together, 72 to 69, with an error bar of 2.4 to 4.0 points. In regular-season games between teams that both made the playoffs it calls 56 to the rank's 52. In the playoff games themselves the two call the same number right, within one point either way; Model B's advantage there is on log-loss, and smaller than in the regular season. In 45 other associations and sections, it is ahead of the official ranking or standings on log-loss in 89 of 93 boys' and girls' seasons and behind in none; on games called right, two of the 93 are slightly behind, both too close to call. For girls, rebuilt the same way, Model B calls 75 of 100 games right across 6A, 5A and 4A to the OSAA rank's 72, with an error bar of 2.8 to 4.4 points, and 72 to 68 in 6A, ahead in ten of twelve seasons.
In past seasons, Model B ordered the middle of the bracket better than the OSAA rank did, and that is where Oregon decides who hosts and who qualifies. Whether it does so this season is scored after the final on November 14, against predictions recorded before the bracket was posted. A rating is a prediction, not a verdict, and one game proves nothing.