Primera Division · Sunday, 13 September 2026. Final score 3–1 (half-time 1–1). Rebuilt from the season as it stood that morning, our rating would have been 45% for over 2.5 goals. This match is older than our frozen ratings ledger, which keeps 30 days, so that figure is a reconstruction from pre-match data rather than a number we published at the time — a distinction worth making, because only the frozen ones prove what we actually said beforehand.
Open this match in the app →| Market | Yes | No | Our call |
|---|---|---|---|
| Over 2.5 goals | 45% | 55% | Under |
| Over 3.5 goals | 25% | 75% | no pick |
| Both teams to score | 51% | 49% | Yes |
The result model puts Atletico Grau at 42%, the draw at 30% and Alianza Atletico at 27%, from expected goals of 1.2 and 0.9.
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. Atletico Grau have 8 in 25 this season (4 of 12 at home), Alianza Atletico 13 in 25 (7 of 13 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 42% and 52%.
Last season still counts, briefly. With 25 and 25 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 44% and 48%.
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 47%.
Head to head. These sides have met 6 times in three years, producing over 2.5 goals in 33%. 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 47%.
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 35%, from expected goals of 1.2 for Atletico Grau and 0.9 for Alianza Atletico. Folding in 30% of that view gives 43%.
Calibration. Tested against 97,729 past matches, our ratings below 55% have run consistently too pessimistic — a figure in the high 30s, for instance, has come in about four points higher. So ratings in that range are lifted part-way back, giving 45%.
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 |
|---|---|---|---|---|
| Atletico Grau | 25 | 32% | 24% | 32% |
| Alianza Atletico | 25 | 52% | 40% | 64% |
More: Atletico Grau season stats · Alianza Atletico season stats · Primera Division table and form. Ratings are calibrated probabilities, not tips — a 60% call is expected to miss two times in five.