How our bet builder model works
Every slip we post comes from the same steps, run the moment both team sheets are confirmed. Here they are in full, along with the test that told us whether to trust the numbers.
1. Wait for the confirmed line-ups
From 40 minutes before kick-off the model checks for team sheets every few minutes. Nothing goes out until both are confirmed, and every slip is posted at least 15 minutes before kick-off. If the line-ups arrive too late, there's simply no slip for that match — we'd rather post nothing than guess who's starting.
2. Pull each starter's recent record
For every outfield starter, the model takes his last ten games of 60 minutes or more, for any club and any competition in our database, reaching back into last season while this one is young. Short cameos are left out because they'd drag a starter's rate down unfairly.
3. Turn the record into a chance
From those games come the player's shots on target per 90 minutes. Then three adjustments:
- Steadying. The rate is pulled towards the usual rate for his position, as if he'd also played six extra games of average football. A hot streak still counts, but not at face value.
- Opponent. Multiplied by how many shots on target the opponent has conceded over its last ten games compared with the average — only half of the difference is believed, and the adjustment is capped between ×0.7 and ×1.4.
- Venue. Home sides produce about 10% more shots on target than average in our data, away sides about 10% fewer.
That gives an expected number of shots on target for this match, and from it the chance of at least one, allowing for the fact that players have good and bad days.
4. Pick the three most likely starters
Goalkeepers are excluded, and every leg has to pass three guardrails:
- at least six qualifying games in the sample;
- landed a shot on target in at least half of them;
- a model chance of at least 45%.
Of the starters who pass, the three most likely make the slip. Each match day the model ranks every match kicking off at the same time and posts the top three.
5. Price the slip as a whole
Legs in the same match are linked. When a team dominates, all its attackers get shots away, so team-mates tend to land, or miss, together. The model lets players on the same team share one match-to-match swing, while the two teams swing independently, and prices the three legs together. The result is the slip's chance of landing and its fair odds: 1 divided by that chance, the price at which it breaks even over time.
One thing the model never uses is bookmakers' odds. The picks come from the stats alone; the fair price is there so you can judge the bookmaker's price, not the other way round.
The backtest: can the numbers be trusted?
Before a single tip went out, we ran the model over 1,145 matches from the 2025/26 season, pricing every outfield starter using only the games that came before each match. The test is simple: when the model says 45%, does it happen about 45% of the time?
| Our chance | Players | Predicted | Landed |
|---|---|---|---|
| Under 30% | 9,418 | 16.8% | 17.3% |
| 30–40% | 2,499 | 34.8% | 35.7% |
| 40–50% | 1,988 | 44.7% | 45.4% |
| 50–60% | 1,039 | 54.3% | 55.7% |
| 60–70% | 291 | 63.6% | 59.8% |
| 70–80% | 38 | 73.3% | 81.6% |
Across 15,274 player predictions the predicted and actual rates track each other closely in every band where there's enough data. The model also beat two simple alternatives on accuracy (its Brier score was 0.178, against 0.190 for a player's raw last-ten hit rate and 0.200 for giving everyone the same chance). The slips it would have built — 341 of them — were predicted to land 16.5% of the time and landed 15.5%.
Since going live
The same test, on every pick we've actually posted: 7 of 45 slips landed all three legs; 80 of 135 individual picks landed (59%, against 58% predicted).
| Our chance | Picks | Predicted | Landed |
|---|---|---|---|
| Under 55% | 50 | 50% | 48% |
| 55–60% | 40 | 57% | 60% |
| 60–65% | 18 | 62% | 72% |
| 65%+ | 27 | 72% | 70% |
What the model doesn't know
- Tactics and team news beyond the team sheet — a striker carrying a knock, a manager setting up to defend.
- Penalty and set-piece duties, except as they show up in a player's record.
- Bookmakers' prices. It tells you what a slip is worth; whether a bookmaker's price beats that is for you to check.
It's a careful estimate, not a crystal ball. Most slips lose, and we publish every one.
Get the picks before kick-off
A new feature: up to three data-picked bet builder slips a day, with fair odds, free in our Telegram channel 15–40 minutes before kick-off. Not guaranteed — subscribers get every slip.
📱 Join the Free ChannelBet builders are a new feature and are not guaranteed: unlike our arbs, most slips lose, and our record shows it. Bet only what you can afford to lose. 18+. BeGambleAware.org