How this works
Nothing here is proprietary. The model is a few dozen numbers and they are all published on this site.
The model
Each side’s scoring rate is built from who is playing:
Those rates become a distribution over total goals, which is where every over/under number on this site comes from. The distribution is deliberately narrower than a textbook Poisson: goals here are less erratic than the standard assumption, so the shape is compressed by a fitted factor, currently 1.120.
Three things that surprised us
- Home advantage is nothing. The fitted home term is +0.0194 on the log scale, about two hundredths of a goal. “Home” is only a stream slot. Any model ported from real football would carry a bias fifteen times too large.
- Players warm up, they do not tire. More matches into a session means more goals, worth roughly 0.6 across a long day. Every operator has their own curve.
- The scoring level drifts more than the players matter. It swung 0.85 goals over the year — about five times the value of knowing who is on the pitch.
Is it any good?
Judge it on calibration, not on how often it picks a winner. This is every prediction on 15,486 matches the model never saw during development, grouped by how confident it was. If the two columns match, a stated probability means what it says.
| We said | It happened | Matches |
|---|---|---|
| 27% | 28% | 216 |
| 36% | 33% | 668 |
| 46% | 43% | 2,227 |
| 55% | 55% | 4,004 |
| 64% | 63% | 4,503 |
| 75% | 74% | 3,025 |
| 83% | 80% | 811 |
What it cannot do
- It is already at its limit. Average error is 1.854 goals against a floor of 1.860. The model is as accurate as its own uncertainty allows; the rest is what a 15-minute match does on its own.
- High-scoring calls run hot. When it says a match is very likely to go high, it is a little over-confident. Trust the middle of the range more than the top.
- It knows nothing about prices. No odds are used anywhere. A well-calibrated probability still loses money against a bookmaker’s margin, so nothing here says whether a price is worth taking.