Primera Division · Sunday, 20 September 2026. Final score 1–1 (half-time 1–1). Before kick-off we rated it 52% over 2.5 goals — the match finished with 2, so that call missed. That rating was frozen into a version-controlled ledger before the game and has not been touched since.
Open this match in the app →| Market | Yes | No | Our call |
|---|---|---|---|
| Over 2.5 goals | 52% | 48% | Over |
| Over 3.5 goals | 30% | 70% | no pick |
| Both teams to score | 53% | 47% | Yes |
The result model puts FBC Melgar at 61%, the draw at 22% and Sport Boys at 17%, from expected goals of 1.97 and 0.95.
The league sets the starting point. Primera Division has produced over 2.5 goals in 52% of its matches, and that is where a team with no record of its own would sit.
Each side's own record. FBC Melgar have 15 in 26 this season (9 of 13 at home), Sport Boys 8 in 26 (5 of 12 away). Those records are pulled toward the league rate with the weight of about 24 matches — enough that two or three unusual games cannot swing a rating — giving 55% and 41%.
Last season still counts, briefly. With 26 and 26 games played this season, last season's rates are still blended in and fade out entirely by game 40 — the point at which our testing showed they stop adding accuracy. A single season is part luck, so each club's record is first pulled toward the league average by 34 games' weight. That moves the two figures to 53% and 45%.
The mix. Weighted 40% home side, 40% away side and 20% league — the split that beat every alternative across 30,582 matches of testing — that gives 50%.
Head to head. These sides have met 5 times in three years, producing over 2.5 goals in 60%. That nudges the number 5% of the way toward the head-to-head pattern — deliberately small, because fixtures change more than reputations do — landing on 50%.
Goal expectation. Separately a Poisson model built from attack and defence strength — using real expected-goals data where the league has it — puts this match at 56%, from expected goals of 1.97 for FBC Melgar and 0.95 for Sport Boys. Folding in 30% of that view gives 52%.
This breakdown is generated from the same inputs the rating uses, so it cannot describe a calculation we did not perform. The full model is set out in the methodology.
| Team | Games | O2.5 | O3.5 | BTTS |
|---|---|---|---|---|
| FBC Melgar | 26 | 58% | 35% | 62% |
| Sport Boys | 26 | 31% | 19% | 38% |
More: FBC Melgar season stats · Sport Boys season stats · Primera Division table and form. Ratings are calibrated probabilities, not tips — a 60% call is expected to miss two times in five.