Value betting algorithm: how RebelBetting finds value bets

A value betting algorithm estimates the real probability of each outcome and flags the bets where a bookmaker's odds are higher than that probability is worth.

RebelBetting is value betting software whose algorithm gets the real probability from the odds of sharp bookmakers, instead of predicting matches from team statistics.

How the algorithm works with RebelBetting

• It collects odds from 120+ bookmakers every minute.
• It removes the margin from the sharp bookmakers' odds to get the fair odds.
• It compares the fair odds with the odds at every soft bookmaker.
• It shows you the bets with a positive expected value and a suggested stake.

1. Sharp odds as the starting point

The algorithm starts from the sharp bookmakers. They accept large stakes from professional bettors and change their odds as soon as that money comes in, which keeps their prices close to the real probability. Soft bookmakers set odds for recreational players and update them later.

2. Remove the margin

Every bookmaker builds a margin into its odds. Say a sharp bookmaker offers 1.95 on both players in a tennis match. 1 ÷ 1.95 is 51.3%, so the two sides add up to 102.6%. The extra 2.6% is the margin. Remove it and each player has a 50% chance, which means fair odds of 2.00.

That's the simplest way to remove a margin. RebelBetting also takes betting bias and market efficiency into account when it sets the fair odds.

3. Compare with the soft bookmakers

If a soft bookmaker offers 2.08 on the same player, the bet pays more than a 50% chance is worth. The expected value is 0.5 × 2.08 − 1 = +4%. That's a value bet.

4. Suggest a stake

The stake follows the Kelly criterion, based on your bankroll and the size of the edge. Your own settings, such as minimum value, odds range and time to kick-off, decide which bets you see.

5. Check again before you bet

Odds move all the time. If the soft odds drop or the sharp odds rise, the value can disappear before you place the bet, and RebelBetting tells you.

There are two kinds of betting algorithm. Prediction models estimate the result from team statistics and form. Market-based models start from the sharp bookmakers' odds. RebelBetting uses the second kind: it doesn't try to predict who wins, it finds the soft bookmakers whose odds are wrong compared with the sharp ones.

It doesn't make every bet win. A +4% bet at odds of 2.08 still loses about half the time. That's variance, and it's why results are judged over hundreds of bets.

You can check the method with the closing line. If you keep getting better odds than the sharp odds just before kick-off, your bets have value. Read more about closing line value, or see how it all fits together on the value betting page.