You found a Value Bet. Great.
But how much of your money should you risk? 10%? 50%? All in?
The answer was solved by a scientist named John Kelly in 1956.
The Formula
The Kelly Criterion tells you the exact percentage of your bankroll to bet.
$$ f = \frac{bp - q}{b} $$
- f = The percentage of your bankroll to bet.
- b = The decimal odds - 1 (e.g., if odds are 2.0, b = 1).
- p = Your probability of winning (e.g., 0.55 for 55%).
- q = Probability of losing (1 - p).
Example Calculation
- Bankroll: 10,000 BDT
- Odds: 2.00 (Even money).
- Your Estimated Win Chance: 55% (0.55).
$$ f = \frac{(1 \times 0.55) - 0.45}{1} = 0.10 $$
Result: The formula says bet 10% of your bankroll (1000 BDT).
The Dangers of "Full Kelly"
While mathematically optimal, betting 10% on a single game is scary. If you lose a few in a row, your bankroll crashes.
Most pros use Fractional Kelly (e.g., Half Kelly).
- Formula says 10%.
- You bet 5%.
This grows your money nearly as fast but with much less variance (swings).
Conclusion
Never guess your stake size. Use Kelly (or Half Kelly) to be disciplined.
If you bet randomly, you will eventually hit zero.
Ready to spot those overpriced odds? Read our Value Betting Guide.
