A value bet is one where the odds imply a lower chance than the true chance of it happening. Over lots of bets, value bets should do better than bets that aren't. The hard part is knowing the true chance.
Expected value in one sum
Expected value is what a bet is worth on average per £1. Multiply your chance of winning by the decimal odds and take away 1.
Say you think a team has a 40% chance of winning. At odds of 3.0 (2/1), the sum is 0.4 × 3.0 − 1 = 0.2. On average you'd get back 20p more than you stake for every £1. At odds of 2.25 (5/4), it's 0.4 × 2.25 − 1 = −0.1. You'd lose 10p per £1 on average.
Quick check: the bet has value if the implied chance of the odds is lower than your chance. 3.0 implies 33.3%. You think 40%. That's value, if you're right.
Why value betting is so hard
- You have to estimate the true chance better than the bookmaker, whose prices are set by experts and sharpened by money from other punters.
- Results swing a lot. Even genuine value bets can lose for hundreds of bets in a row before the maths shows up.
- Bookmakers watch for customers who keep beating their prices. They often limit or close those accounts.
How value betting software finds bets
Some bookmakers take big bets and move their prices quickly. Their odds are often called sharp. Others are slower to move. Value betting tools compare the two and flag prices at the slower bookmakers that look too big.
Say a sharp bookmaker prices a tennis match at 2.05 and 1.85. Those add up to a 2.8% margin. Take the margin off and the fair odds are about 2.11 and 1.90, a 47.4% chance for the first player.
If another bookmaker offers 2.20 on that player, the expected value is 0.474 × 2.20 − 1, which is about +4.4% per £1. That's a value bet, if the sharp price is right.
- Each bet still wins or loses. A 4% edge needs thousands of bets before the results reliably show it.
- Prices move. By the time you place the bet, the value may be gone.
- Bookmakers that get beaten often limit accounts, usually faster for people who only take value prices.
Value betting tools we rate
Size and check your bets:Kelly criterion calculatorOdds converter
Where value thinking still helps
Even if you never chase value seriously, thinking this way helps you spot bad bets. Accas with big margins, novelty markets and boosted odds that aren't much of a boost all look different once you turn the odds into a percentage.
Turn any price into a percentage with the odds converter.Odds converter →Questions people ask
Is value betting a way to make money?
Rarely. Hardly anyone beats the bookmakers over the long run, and those who do usually get their accounts limited. Treat betting as entertainment you pay for.
What is a closing line?
The final odds before an event starts. Serious bettors compare the price they took with the closing price to judge if they're getting value.
How much should I stake on a value bet?
Level stakes of 1% to 2% of your betting bank keep things simple. The Kelly criterion sizes stakes by your edge, but most people use a fraction of it because their estimates aren't exact.