What Is the Kelly Criterion? A Professional Bankroll Management Formula for Sports Betting

By admin , 22 December 2025

In sports betting, winning a few bets doesn’t matter as much as surviving long term. Many bettors are excellent at picking games but still lose money because they stake incorrectly.

That’s exactly why the Kelly Criterion is widely used by professional bettors and investors as a gold-standard bankroll management method.

1️⃣ What Is the Kelly Criterion?

The Kelly Criterion is a mathematical formula that helps you determine:

👉 How much of your bankroll you should bet on a single wager
👉 Based on your real edge (value) versus the bookmaker’s odds

The main goals of Kelly:

Maximize long-term bankroll growth
Reduce the risk of bankroll ruin
Prevent overbetting when no real value exists

2️⃣ The Kelly Criterion Formula (Basic Version)

f^* = \frac{bp - q}{b}

$f$ $*$ $=$ $bbp$ $-$ $q$ $$

Where:

f*: Fraction of bankroll to bet
b: Odds − 1 (decimal odds)
p: Your estimated probability of winning
q: Probability of losing (q = 1 − p)

3️⃣ Practical Example (Very Important)

Assume you analyze a football match and estimate:

Win probability: 60% → p = 0.6
Bookmaker odds: 2.20 → b = 1.2
q = 0.4

Applying the formula:

f^* = \frac{(1.2 \times 0.6) - 0.4}{1.2} = \frac{0.72 - 0.4}{1.2} = 0.2667

$f$ $*$ $=$ $1.2$ $($ $1.2$ $\times$ $0.6$ $)$ $-$ $0.4$ $$ $=$ $1.20.72$ $-$ $0.4$ $$ $=$ $0.2667$

📌 Conclusion:
According to full Kelly, you should stake 26.67% of your bankroll on this bet.

4️⃣ Why Professionals Trust the Kelly Criterion

According to long-term betting studies and low-margin bookmakers such as Pinnacle, the Kelly Criterion helps bettors:

✅ Bet only when true value exists
✅ Avoid overbetting when odds are inefficient
✅ Maintain an edge over thousands of bets, not just a few wins

Kelly is not a get-rich-quick system. It’s a tool that allows small edges to compound into significant profit over time.

5️⃣ Fractional Kelly – The Version You Should Actually Use

The biggest drawback of full Kelly:

High volatility
Large drawdowns during losing streaks

👉 That’s why most professional bettors do not use 100% Kelly, but instead:

Half Kelly (1/2 Kelly) – lower risk
Quarter Kelly (1/4 Kelly) – much smoother and more stable

📌 In football betting:

1/4 Kelly is often the most practical choice, balancing growth and emotional control.

6️⃣ Pros and Cons of the Kelly Criterion

✅ Advantages

Maximizes long-term bankroll growth
Enforces disciplined staking
Perfect for value betting strategies

❌ Disadvantages

Relies heavily on accurate probability estimation
Wrong assumptions = higher risk
Not suitable for emotional or impulse bettors

7️⃣ How to Apply Kelly to Football Betting

Step 1: Analyze the match and estimate win probability
Step 2: Compare your probability with bookmaker odds
Step 3: Calculate the Kelly stake
Step 4: Apply Fractional Kelly (1/4 or 1/2)
Step 5: Track results over the long term

8️⃣ Kelly Works Best With Sharp Odds

The Kelly Criterion performs best when betting with bookmakers that offer:

Competitive odds
Efficient Asian handicap lines
High liquidity and fair limits

You can apply Kelly-based staking on the following platforms:

👉 Fun88
https://www.trungxoso88.com/vi/Angel88VN/Register/?aff=331561

👉 188BET
http://www.188japan.com/vi-vn/?affiliatecode=59100

👉 Dafabet
https://www.dffgames.com/vn?btag=656226

9️⃣ Final Thoughts

The Kelly Criterion is a powerful bankroll management weapon
It only works if you truly have an edge
👉 Always prioritize Fractional Kelly
👉 Never use Kelly to chase losses or bet emotionally