Primera Nacional · Sunday, 11 October 2026. Final score 1–0 (half-time 0–0). Before kick-off we rated it 66% under 2.5 goals — the match finished with 1, so that call landed. 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 | 34% | 66% | Under |
| Over 3.5 goals | 14% | 86% | no pick |
| Both teams to score | 41% | 59% | No |
The result model puts Ciudad de Bolívar at 35%, the draw at 32% and San Telmo at 33%, from expected goals of 0.98 and 0.94.
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. Ciudad de Bolívar have 8 in 32 this season (5 of 16 at home), San Telmo 12 in 32 (6 of 16 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 27% and 34%.
Last season still counts, briefly. With 32 and 32 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 27% and 34%.
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 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 30%, from expected goals of 0.98 for Ciudad de Bolívar and 0.94 for San Telmo. Folding in 30% of that view gives 31%.
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 34%.
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 |
|---|---|---|---|---|
| Ciudad de Bolívar | 32 | 25% | 13% | 41% |
| San Telmo | 32 | 38% | 19% | 34% |
More: Ciudad de Bolívar season stats · San Telmo season stats · Primera Nacional table and form. Ratings are calibrated probabilities, not tips — a 60% call is expected to miss two times in five.