The 3 Odds Formats
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1. Decimal (Most Common in Europe + Caribbean)
Total return = stake × odds
Example: stake 10 units, odds 1.75 → return 17.50 (profit 7.50)
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2. Fractional (UK)
Odds 3/1 means: for every 1 staked, you win 3 (plus your stake back)
3/1 = 4.00 decimal. 1/2 = 1.50 decimal.
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3. American (Moneyline)
- +200→ stake 100, win 200 (on top of stake returned)- -150→ stake 150 to win 100Calculating Implied Probability
Formula: Probability (%) = 100 ÷ decimal odds
| Odds | Implied Probability |
|------|---------------------|
| 1.50 | 67% |
| 2.00 | 50% |
| 3.00 | 33% |
| 5.00 | 20% |
If you believe the true probability is higher than the implied probability — you have positive expected value.
The Magic of Value Betting
If the bookmaker offers 2.50 (40% implied), but you estimate the real chance at 55% — that's a value bet. Across many such bets, you'll be profitable long-term.