The Martingale betting system is the best-known way people try to beat the casino by changing their stake after wins or losses. There are many others, too.
None of them change the odds. Here’s how the popular systems work, what they really do to your results, and why a losing streak is more likely than it feels.
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1How the Martingale betting system works
The Martingale is used on even-money bets such as red or black in roulette. You double your stake after every loss. When you finally win, you recover all your losses plus a profit equal to your first stake. Then you start again.
It sounds foolproof. The problem is how fast the stakes grow.
2How quickly the stakes grow
| Losses in a row | Next stake | Total lost so far |
|---|---|---|
| 1 | £2 | £1 |
| 3 | £8 | £7 |
| 5 | £32 | £31 |
| 7 | £128 | £127 |
| 8 | £256 | £255 |
| 10 | £1,024 | £1,023 |
Starting at just £1, eight losses in a row means you’ve lost £255 and need to stake £256 to win back a single pound. Table limits or your budget usually stop you before that.
3A losing streak is more likely than it feels
On European roulette, an even-money bet loses 19 times in 37, because of the zero. The chance of losing eight in a row is about 1 in 207. That sounds rare, but over 200 spins there’s roughly a 37% chance you’ll hit at least one run of eight losses.
So the Martingale betting system tends to win small amounts often, then lose a large amount occasionally. Over time, those large losses wipe out the small wins and more.
4Other popular systems
- Paroli (reverse Martingale): double after a win, and reset after a set number of wins or a loss. Losses are small, but most winning runs end before they pay much.
- D’Alembert: raise your stake by one unit after a loss, and lower it by one after a win. Gentler than the Martingale, but still loses to the edge.
- Fibonacci: stakes follow the sequence 1, 1, 2, 3, 5, 8, 13… after losses. Stakes grow more slowly, but a long streak still gets expensive.
5Why no system beats the house edge
Every bet on a casino game has the same expected cost, whatever you staked before it. A system can change when your wins and losses arrive, but not the average. Over enough bets, you’ll lose roughly the house edge on everything you stake, and systems often make you stake more.
Believing a win must be coming after a run of losses is the gambler’s fallacy, which is what most systems rely on.
6What to do instead
- Use flat stakes you’re comfortable losing.
- Set a session budget and a win point where you’ll stop.
- Never raise your stakes to chase losses.
- Pick lower-edge bets, such as European roulette over American.
For more on budgeting, read our bankroll rules, and see the roulette bets and odds guide for the cost of each bet.