Dexsport is running a sportsbook with decimal odds alongside prediction markets where shares trade between 1 and 99 cents, and the pairing makes a quiet point about how prices work. On a sampled set of Yes and No pairs, the two sides added up to 101 or 102 cents. That's the same overround a bookmaker builds into a football market, just expressed in a different unit.
The operator, Dexapp LTD, holds an Anjouan licence and its terms rule out arbitrage betting. So the exercise is less about finding a loophole and more about reading a number correctly before acting on it. The maths is simple enough to do on a phone: raw implied probability is 1 divided by the decimal odds. Odds of 2.50 become 40.0%. Odds of 1.50 become 66.7%.
Why the raw percentage overstates the chance
Those raw figures include the bookmaker's margin, which means they overstate the true chance of each outcome. To strip the margin out, you sum the raw implied probabilities for every outcome in the market. The total comes in above 100%, and each raw number is divided by that total to produce a fair probability.
Take an illustrative three-way football market priced at Home 2.50, Draw 3.40 and Away 3.00. The raw implied probabilities add up to 102.7%. After the margin is removed, the fair figures come to 38.9%, 28.6% and 32.4%. That's the version of the market you can actually compare against your own view of the match.
Expected value is a statement about an average
Expected value per unit staked is (your probability × decimal odds) − 1, assuming your probability is the right one. At odds of 2.50, a 45% estimate gives +12.5% EV. A 40% estimate gives 0%, which is break-even before any costs. A 38.9% estimate lands at about −2.7% EV.
The catch is that positive expected value describes an average over many bets. Any single bet still wins or loses outright, and cold streaks can stretch long even when the edge is real. A run of ten wins proves very little on its own — variance can produce long streaks in either direction. Judge a method over hundreds of bets, not a weekend.
Four habits that bend your own number
Personal probability estimates tend to go wrong in predictable ways: overconfidence, loyalty to favourite teams, small samples and stale information. Overconfidence is the one that does the most damage quietly. Estimate 45% when the true probability is 40% and you've created a purely imaginary edge — one that looks like value on the screen and behaves like a donation at settlement.
Stale information is the other one that bites. Markets react to team news within minutes, so an estimate formed before a lineup change may describe a different match from the one on the board. The final price before an event tends to land close to the fair figure, because markets absorb news and sharp money up to kick-off. Bets struck at better odds than the final price, over a long sample, suggest the estimates hold up. Bets struck at worse odds, time after time, suggest the market saw something first.
Prediction markets show the same thing in cents
Prediction markets display probability directly: Yes at 40 cents implies a 40% chance. Any combined Yes and No price above 100 cents plays the role of a margin — the same overround, just wearing different clothes. Dexsport's sampled pairs at 101 or 102 cents sit inside that convention.
Implied probability turns any price into a percentage, whether it's 1 divided by decimal odds or a share price in cents. Value betting is best treated as a way to read prices, never as a promise of profit. Anyone using these markets should check the law where they live, bet only at legal age, and expect that KYC or AML checks may apply. Stakes should be limited to what you can afford to lose.
