Set a bankroll you could lose entirely, then bet a fixed unit of 1–2% of it on each play. Flat units keep your results comparable and survive the long losing streaks that even good bettors hit: a 52.4% bettor has about a 50% chance of losing 8 in a row somewhere in 500 bets.
Key points
- A unit is your standard bet size, usually 1–2% of your bankroll.
- Flat staking beats “betting more when you feel confident” for almost everyone.
- The Kelly criterion says how much an edge is worth betting; most people who use it bet a quarter or half of what it says.
- With no edge, Kelly says bet nothing. That's the most useful thing it tells you.
Units and flat staking
Pick a bankroll, the amount set aside only for betting, and divide it into units. With a 1,000 bankroll and a 1% unit, every standard bet is 10. Strong opinions can be 2 units; nothing goes higher. Results are then counted in units won or lost, which lets you compare a month at a small bankroll with a month at a bigger one.
Flat staking matters because most bettors size up exactly when they're overconfident. A record built on equal stakes shows whether your picks are good. One built on varying stakes mostly shows which bets you happened to feel strongly about.
Losing streaks are normal
Even with an edge, streaks are long. For a bettor who wins 52.4% of bets at -110 (exactly break-even), the chance of at least one losing streak of a given length somewhere in 500 bets:
| Losing streak of at least | Chance in 500 bets |
|---|---|
| 6 in a row | 95.7% |
| 8 in a row | 49.9% |
| 10 in a row | 14.3% |
At 5% a bet, eight straight losses cost a third or more of your bankroll. At 1%, it's 8 units and a shrug.
The Kelly criterion
Kelly gives the bet size that grows a bankroll fastest if you know your true edge:
Bet fraction = (b × p − q) ÷ b
b = decimal odds − 1, p = your win chance, q = 1 − p
| Your true win chance at -110 | Full Kelly | Quarter Kelly |
|---|---|---|
| 52.4% (break-even) | 0% | 0% |
| 55% | 5.5% | 1.4% |
| 57% | 9.7% | 2.4% |
The catch is that nobody knows their true win chance, and overestimating it makes full Kelly swing wildly. That's why people who use it bet a fraction, and why quarter Kelly at a realistic edge lands right back near the 1–2% unit.
Simple rules that work
- Never add money to the bankroll to chase a loss.
- Recalculate the unit monthly, not after every bet.
- Count parlays at a smaller stake; they lose far more often (see why parlays lose).
- If a bad run changes how you feel about the money, the unit is too big.
Try it with free coins. FakeBet gives you real sportsbook odds, 500 free coins to start and a full record of every bet, so you can practice all of this without risking money. Get FakeBet on Google Play.