Primera Nacional · Monday, 28 September 2026. Final score 2–2 (half-time 0–2). Before kick-off we rated it 66% 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 | 37% | 63% | Under |
| Over 3.5 goals | 15% | 85% | no pick |
| Both teams to score | 44% | 56% | No |
The result model puts Gimnasia Jujuy at 56%, the draw at 26% and San Martin Tucuman at 18%, from expected goals of 1.56 and 0.77.
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. Gimnasia Jujuy have 16 in 30 this season (7 of 15 at home), San Martin Tucuman 9 in 30 (3 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 43% and 30%.
Last season still counts, briefly. With 30 and 30 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 38% and 29%.
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 33%.
Head to head. These sides have met 3 times in three years, producing over 2.5 goals in 0%. 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 31%.
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 41%, from expected goals of 1.56 for Gimnasia Jujuy and 0.77 for San Martin Tucuman. Folding in 30% of that view gives 34%.
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 37%.
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 |
|---|---|---|---|---|
| Gimnasia Jujuy | 30 | 53% | 17% | 63% |
| San Martin Tucuman | 30 | 30% | 10% | 43% |
More: Gimnasia Jujuy season stats · San Martin Tucuman season stats · Primera Nacional table and form. Ratings are calibrated probabilities, not tips — a 60% call is expected to miss two times in five.