📖 What is Fractional Kelly?

Fractional Kelly is a more conservative version of the Kelly Criterion. Instead of betting the full amount suggested by the formula, you bet only a fraction of that amount (usually 25% or 50%).

This approach significantly reduces bankroll volatility and the risk of ruin while maintaining most of the growth potential.

Fractional Kelly is recommended for the vast majority of bettors, especially beginners.

📊 Comparison: Full Kelly vs Fractional

Full Kelly (100%)

  • ✓ Maximum theoretical growth
  • ✗ High volatility
  • ✗ High risk of ruin
Profile: Professional

Kelly 50%

  • ✓ Good balance
  • ✓ Reduces volatility
  • ✗ Lower growth
Profile: Intermediate

Kelly 25%

  • ✓ Low volatility
  • ✓ Controlled risk
  • ✓ Ideal for beginners
Profile: Everyone

Kelly 10%

  • ✓ Very low risk
  • ✓ Protects bankroll
  • ✗ Slow growth
Profile: Small bankrolls

🧮 Fractional Kelly Calculator

Full Kelly
0%
Adjusted Kelly
0%
Expected Value
0%
Recommended Bet
$0.00
Risk Level:

📊 Comparison: Full Kelly vs Kelly 50% vs Kelly 25%

ProbabilityOddsFull KellyKelly 50%Kelly 25%Bet ($1000)
55%2.0010%5%2.5%$25
60%2.0020%10%5%$50
65%2.0030%15%7.5%$75
55%2.508.3%4.2%2.1%$21
60%2.5016.7%8.3%4.2%$42
55%3.006.7%3.3%1.7%$17

📈 Simulation: Bankroll Growth

Full Kelly
$0.00
Kelly 50%
$0.00
Kelly 25%
$0.00
Fixed Bet 5%
$0.00
Full Kelly:
$0
0%
Kelly 50%:
$0
0%
Kelly 25%:
$0
0%
Fixed Bet 5%:
$0
0%
Initial Bankroll:
$0
0%
* Simulation based on controlled randomness

✅ Advantages of Fractional Kelly

Protects Bankroll

Reduces risk of ruin

Consistent Growth

Maintains potential

Less Stress

Reduced volatility

Ideal for Beginners

Learn safely

For Educational Purposes Only: Bet responsibly.