Primera Nacional · Sunday, 4 October 2026. Final score 2–2 (half-time 2–0). Before kick-off we rated it 72% under 2.5 goals — the match finished with 4, 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 | 31% | 69% | Under |
| Over 3.5 goals | 9% | 91% | no pick |
| Both teams to score | 38% | 62% | No |
The result model puts Chaco For Ever at 41%, the draw at 35% and Defensores De Belgrano at 25%, from expected goals of 0.98 and 0.7.
The league sets the starting point. Primera Nacional has produced over 2.5 goals in 30% of its matches, and that is where a team with no record of its own would sit.
Each side's own record. Chaco For Ever have 9 in 31 this season (5 of 15 at home), Defensores De Belgrano 8 in 31 (4 of 15 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 29% and 28%.
Last season still counts, briefly. With 31 and 31 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 29% and 28%.
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 29%.
Head to head. These sides have met 5 times in three years, producing over 2.5 goals in 20%. 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 28%.
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 24%, from expected goals of 0.98 for Chaco For Ever and 0.7 for Defensores De Belgrano. Folding in 30% of that view gives 27%.
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 31%.
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 |
|---|---|---|---|---|
| Chaco For Ever | 31 | 29% | 10% | 39% |
| Defensores De Belgrano | 31 | 26% | 0% | 35% |
More: Chaco For Ever season stats · Defensores De Belgrano season stats · Primera Nacional table and form. Ratings are calibrated probabilities, not tips — a 60% call is expected to miss two times in five.