What is a value bet?
By Naftali, founder of Sidefoot · Last updated 19 October 2026
A value bet is one where the odds are longer than the real chance of it happening. If a team truly wins 50% of the time, fair odds are 2.00, so any price above 2.00 is value. Value doesn't mean the bet will win. It means that, repeated many times at that price, the average return is positive, but only if your estimate of the chance is right.
How to work out if a bet is value
- Estimate the chance yourself, for example 50%.
- Turn the odds into the bookmaker's chance: 1 ÷ decimal odds. Odds of 2.20 mean 45.5%.
- If your chance is higher than the bookmaker's, the price is value. Here, 50% beats 45.5%.
To see how much value, multiply your chance by the decimal odds and subtract 1. At 50% and odds of 2.20: 0.50 × 2.20 − 1 = 0.10. That's an average return of 10p per £1 staked, over many bets like it.
Odds you need for a bet to be value
Fair odds are 1 ÷ your chance. Anything longer is value; anything shorter isn't.
| Your estimated chance | Fair decimal odds | Value if the odds are above |
|---|---|---|
| 80% | 1.25 | 1.25 |
| 70% | 1.43 | 1.43 |
| 60% | 1.67 | 1.67 |
| 50% | 2.00 | 2.00 |
| 40% | 2.50 | 2.50 |
| 33% | 3.00 | 3.00 |
| 25% | 4.00 | 4.00 |
| 20% | 5.00 | 5.00 |
Why value bets still lose
A value bet on a 40% chance still loses 60% of the time. Five losses in a row happen about 1 time in 13, even when your estimate is spot on. Value only shows up over a large number of bets, which is why stakes should be small.
The hard part: your estimate
The maths is easy. The estimate is where it goes wrong. Bookmakers in the big European leagues price matches carefully, so when your number is far from theirs, the likeliest explanation is that you've missed something: an injury, a rested squad, a new manager. A real edge is usually small.
How Sidefoot looks for value
Sidefoot builds its own chance for every match from team strength (Elo), recent chance quality (xG) and team news, then blends it 60/40 with the market. It compares that with the bookmaker's chance, with their margin removed. We treat gaps of 3–8% as believable, and flag gaps of 10% or more to check the news first, because the model may be missing something.
FC Augsburg v Union Berlin, Union Berlin to win: bookie's chance 24.7%, our chance 32.7%, edge +8.0%, average return +26p per £1 if our chance is right
Our chance is a model estimate, not a certainty.
56 tracked picks, every pick locked before kick-off. Early results are positive but the sample is far too small to mean anything. We publish the full record, losses included.
Questions
Does a value bet always win?
No. Value is about the price, not the result. A value bet can lose many times in a row.
How do I know if a bet is value?
Compare your own estimate of the chance with 1 ÷ the decimal odds. If yours is higher, the price is value, provided your estimate is right.
What's a realistic edge?
Small. Sidefoot treats 3–8% as believable. Gaps of 10% or more usually mean the model, or you, have missed some news.
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