Predictions
How scoring works
Most prediction leagues pay a flat 3 points for an exact score and 1 for the result. That rewards backing favourites. This one prices every call by how surprising it was.
The idea in one line
Your payout is proportional to the information your call carried. In plain terms: the less likely your scoreline was, the more calling it correctly is worth — far more than someone who called the obvious one.
points = k × −log₂(p)
where p is the probability the model assigned to what you predicted. That quantity, −log₂(p), is the surprisal of the event, measured in bits. The model runs server-side and its probabilities are never published: what you see is the payout, not the odds.
Where the probabilities come from
- 1
Attack and defence strengths per club
Every finished result in the database is read to work out how many goals each club scores and concedes relative to the league average. Clubs with few games played are shrunk toward the average, so three fixtures cannot produce a wild rating.
- 2
Expected goals for the fixture
Home strength times away weakness, adjusted for the home-advantage effect measured across the whole dataset. This gives two numbers — the expected goals for each side.
- 3
A full scoreline grid
Those two expectations produce a probability for every scoreline from 0-0 to 8-8. The grid gets a Dixon–Coles low-score correction, because plain independent Poisson reliably under-counts 0-0, 1-0, 0-1 and 1-1 — draws happen more often than naive maths expects.
- 4
Your price, frozen
When you submit, the probability of your exact scoreline and of your result are both stored on the prediction. Later results change the model but never your payout — the price you were quoted is the price you get.
A worked example
Priced live, right now, for Man City v Brighton. Same fixture, different calls — note how the payout climbs as the scoreline gets bolder.
| Your call | Exact pays | Result only |
|---|---|---|
| 1–0 | 7 | 1 |
| 2–1 | 7 | 1 |
| 1–1 | 7 | 6 |
| 3–1 | 7 | 1 |
| 2–3 | 13 | 8 |
| 3–3 | 14 | 6 |
| 4–3 | 15 | 1 |
Read the top and bottom rows together: the chalk scoreline pays 7, the wild one pays 15. Same fixture, same effort, very different reward for being right.
The rules, plainly
Exact scoreline
3–40 pts
Scaled by surprisal
Right result only
1–12 pts
Also scaled
Wrong result
0 pts
Never negative
- An exact call always pays strictly more than the result alone, even on the rare fixture where the maths would say otherwise.
- Payouts are capped at 40 points so a 7–6 lottery ticket cannot outweigh a season of careful calls.
- A fixture opens for predictions a fortnight before kickoff and closes an hour before it. You can change or withdraw a call at any point in between; changing it re-prices against the model as it stands at that moment.