Bet Sizing in Sports Betting: How Much Should You Really Risk?
Most bettors focus on who to bet.
Professionals focus on how much to bet.
Because even great picks fail when bet sizing is wrong.
Why Bet Sizing Matters More Than Picks
You can:
- Win 55% of your bets
- Still lose money
- Or go broke entirely
All because of poor sizing.
Bet sizing controls:
- Volatility
- Drawdowns
- Long-term survival
It’s the difference between variance and ruin.
The Most Common Bet Sizing Mistake
The biggest mistake bettors make:
Betting based on confidence instead of math.
Confidence is emotional.
Math is structural.
When bet size changes based on “feel,” variance becomes lethal.
Flat Betting: The Foundation Strategy
Flat betting means:
- Same unit size
- Every wager
- Regardless of confidence
Typical flat bet sizing:
- 1–2% of bankroll per bet
Why it works:
- Controls drawdowns
- Prevents emotional escalation
- Survives long losing streaks
Flat betting doesn’t maximize upside — it maximizes longevity.
What Happens When You Bet Too Much
Overbetting leads to:
- Extreme swings
- Emotional decision-making
- Chasing losses
- Bankroll collapse
A 10% bet size only needs a short losing streak to end everything.
Variance doesn’t care how confident you are.
The Kelly Criterion (And Why Most Bettors Misuse It)
Kelly betting sizes wagers based on perceived edge.
In theory, it’s optimal.
In practice:
- Edges are estimated poorly
- Inputs are noisy
- Errors compound quickly
Many bettors use fractional Kelly (¼ or ½ Kelly) to reduce risk — but only if their edge estimation is accurate.
Most bettors overestimate their edge.
Progressive Bet Sizing: Dangerous by Design
Systems that increase bet size after losses (Martingale-style):
- Assume losses will stop soon
- Ignore tail risk
- Magnify exposure at the worst time
Progressions don’t eliminate variance.
They weaponize it against you.
A Simple Bet Sizing Framework
For most bettors:
- Define a bankroll
- Risk 1% per bet
- Never adjust mid-session
- Review results only after large samples
This approach isn’t exciting — but it works.
Why Professionals Bet Small
Pros don’t chase:
- Big scores
- Short-term streaks
They chase:
- Survival
- Scalability
- Long-term edge realization
Small bets allow them to stay in the game long enough for math to matter.
Bet Sizing and Psychological Control
Proper sizing:
- Reduces tilt
- Prevents chasing
- Keeps decision-making rational
If a loss hurts emotionally, the bet was too large.
Final Thoughts
Bet sizing is boring.
That’s why it works.
The goal isn’t to win today — it’s to still be betting next year.
If you control bet size, variance becomes manageable.
If you don’t, no system can save you.