Martingale
The martingale is a betting system where you double your stake after every loss, hoping the next win recovers all your losses plus one base bet.
Also called martingale system, martingale strategy, doubling system, double-up system
The martingale is used on near even-money bets. You start with a small base bet, double it after each loss and go back to the base bet after a win. A win recovers the losses and leaves you one base bet ahead.
Example. You start at 1 on red at European roulette. After seven losses in a row you have lost 1 + 2 + 4 + 8 + 16 + 32 + 64 = 127. The next bet is 128, all to end up 1 ahead. Each spin loses 19 times in 37, so the chance of seven losses in a row is about 1 in 106.
What people get wrong. A win does not have to come before the money runs out. Your bankroll and the table's maximum bet are both limited, so a long enough losing run ends the system with a large loss. Many small wins and one rare big loss add up to the same thing as flat betting: you lose the house edge, here about 2.7%, on everything you stake.
The martingale does not change the expected value of any bet. The feeling that a win is due is the gambler's fallacy.
Related terms
- Gambler's fallacy
The gambler's fallacy is the mistaken belief that a random result is more or less likely to happen because of what happened in earlier rounds.
- Expected value (EV)
Expected value (EV) is the average result of a bet if you could repeat it a huge number of times, found by weighting each possible outcome by its chance.
- Bankroll
A bankroll is the fixed amount of money you set aside for gambling and can afford to lose, kept separate from the money you need to live on.
- House edge
The house edge is the share of each bet a casino expects to keep on average over the long run, equal to 100% minus the game's RTP.