SPORTS BETTING MATH APPLIED PROBABILITY INSTITUTE
Kelly Criterion Simulator

Kelly Criterion Simulator

Calculate optimal bet sizing using full, half, and quarter Kelly criterion to maximize geometric bankroll growth while minimizing drawdown.

Inputs

Implied Probability
50.00%
Expected Edge
10.00%
Kelly Formula
f* = (b × p - q) / b
b = decimal odds - 1
p = win probability
q = 1 - p

Result

Full Kelly
Kelly Fraction
0.00%
Stake Amount
$0.00
Risk of Ruin
0.00%
Half Kelly
Kelly Fraction
0.00%
Stake Amount
$0.00
Risk of Ruin
0.00%
Quarter Kelly
Kelly Fraction
0.00%
Stake Amount
$0.00
Risk of Ruin
0.00%

FAQ

What is the Kelly Criterion?

The Kelly Criterion is a mathematical formula used to determine the optimal size of a series of bets in order to maximize the logarithm of wealth.

Why use Half or Quarter Kelly?

Full Kelly can lead to extreme volatility and severe bankroll drawdowns. Fractional Kelly reduces variance and the risk of ruin while still offering growth.

How is Expected Edge calculated?

Edge is calculated by comparing your true win probability to the implied probability of the odds. A positive edge means the bet is profitable long-term.

What if the Kelly formula gives a negative number?

A negative Kelly fraction means you do not have an edge over the bookmaker, and you should not make the bet.

What is the Risk of Ruin?

Risk of Ruin is the probability of losing a significant portion (or all) of your bankroll. Fractional Kelly helps minimize this risk.

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