The Martingale is the oldest and most popular betting system in roulette, and it sounds foolproof. Bet one unit on red. If you lose, double the bet. Keep doubling until you win, and the win recovers every loss so far plus one unit profit. Then start again at one unit. Since red must come up eventually, how can you lose?
You can lose because "eventually" can take longer than your bankroll or the table limit allows, and because the system does nothing to the house edge. This article puts exact numbers on both, using the European single-zero wheel used at the roulette table on this site.
Key takeaways
- The Martingale turns many small wins into one rare, very large loss. It does not change the odds of any spin.
- On a single-zero wheel, an even-money bet loses 51.35% of the time. Seven losses in a row happen once in about 106 attempts.
- In 200 spins, the chance of meeting at least one run of seven or more losses is about 60%.
- After seven losses you are 127 units down and must stake 128 to win back one unit.
- Whatever the progression, you still lose 2.70% of everything you stake, on average. No betting system changes that.
How the Martingale works
Here is the progression from a one-unit starting bet. Each row is the next bet after another loss:
| Bet number | Stake | Total lost if this bet also loses | Result if this bet wins |
|---|---|---|---|
| 1 | 1 | 1 | +1 |
| 2 | 2 | 3 | +1 |
| 3 | 4 | 7 | +1 |
| 4 | 8 | 15 | +1 |
| 5 | 16 | 31 | +1 |
| 6 | 32 | 63 | +1 |
| 7 | 64 | 127 | +1 |
| 8 | 128 | 255 | +1 |
| 9 | 256 | 511 | +1 |
| 10 | 512 | 1,023 | +1 |
Look at the last column: however deep the run goes, a win only ever brings back one unit. Now look at the stakes. With a 10-chip base bet, the tenth bet is 5,120 chips, risked to win 10.
How likely is the losing streak?
On a single-zero wheel there are 37 pockets: 18 red, 18 black and the green zero. A bet on red therefore wins 18 times in 37 and loses 19 times in 37, or 51.35%. The chance of several losses in a row is that figure multiplied by itself:
| Losses in a row | Chance for a given run | About 1 in | Units lost by then |
|---|---|---|---|
| 5 | 3.57% | 28 | 31 |
| 6 | 1.83% | 55 | 63 |
| 7 | 0.94% | 106 | 127 |
| 8 | 0.48% | 207 | 255 |
| 10 | 0.13% | 784 | 1,023 |
One chance in 106 sounds safe. The problem is that you are not attempting it once. Every spin is another chance for a streak to start, and over a session the chances add up fast:
- In 100 spins, the chance of at least one run of seven or more losses is about 36%.
- In 200 spins, it is about 60%.
- Even a run of eight or more shows up in 200 spins about 37% of the time.
Streaks like these are not bad luck or a sign that something is wrong with the wheel; they are what randomness normally looks like. Our guide to how long a losing streak to expect goes further.
The maths of a Martingale session
Suppose you bring 127 units, enough to survive six losses and place the seventh bet. Each cycle of the system ends one of two ways:
- With probability 99.06%, a win arrives within seven spins and you bank +1.
- With probability 0.94%, seven losses in a row take the entire 127.
Multiply out and the average result per cycle is about −0.21 units. On average each cycle also puts about 7.6 units through the wheel, and −0.21 ÷ 7.6 is −2.70%, exactly the house edge of a single-zero wheel. The system has not removed the edge. It has only reshaped the losses, into many small wins and occasional disasters.
And the disaster is not rare over a whole evening. With that 127-unit bankroll, the chance that a seven-loss streak arrives before you have banked ten units is about 9%. Before you have banked 50 units, it is about 38%. Doubling your money takes 127 winning cycles without a single seven-loss streak, and the chance of that is only about 30%. The other 70% of the time, the streak comes first.
Table limits end the progression for you
Every real table has a maximum bet. If the minimum is 10 and the maximum is 1,000, you can place 10, 20, 40, 80, 160, 320 and 640, seven bets, and the eighth, 1,280, is not allowed. The limit caps how long you can chase, whatever your bankroll. It is one reason the system has never worked for anyone in the long run.
What about the other systems?
Every progression hits the same wall, because no pattern of bet sizes can change the probability of the next spin:
- Reverse Martingale (Paroli): double after wins instead. Small losses, occasional runs of wins, same edge.
- Grand Martingale: double and add a unit. Bigger wins when it works, faster ruin when it does not.
- D'Alembert: raise by one unit after a loss, drop by one after a win. Gentler, same edge.
- Fibonacci and Labouchère: slower progressions, same destination.
Why betting systems cannot beat the RNG explains the general principle, and flat bets outlast clever ones shows what level stakes do to how long your bankroll lasts. The belief that red is "due" after a run of blacks is the gambler's fallacy: the wheel has no memory.
The zero is the whole story
Without the zero, red would win exactly half the time and the Martingale would break even on average. The single green pocket tilts every even-money bet by 2.70% in the house's favour. A double-zero wheel, with two green pockets, doubles the tilt to 5.26%, which makes every system worse still. Single zero vs double zero compares the two, and why every roulette bet has the same house edge explains why switching bets does not help either.
What to do instead
If you enjoy roulette, the honest approach is to treat it as entertainment with a known price:
- Set a session budget you are comfortable losing, and a time limit. See setting a bankroll limit.
- Bet flat. Level stakes keep each spin's risk the same and make a budget last longer.
- Decide your stop rules in advance, for losses and for wins, and keep them.
- Never raise your stakes to win back losses. That is the Martingale in disguise, and chasing losses is how small losses become large ones.
The Roulette series of the strategy playbooks is built around exactly this. Roulette Reset is a practical guide to betting smart, not chasing losses. Roulette Precision sets out every bet's coverage, payout and variance in tables. The Roulette Discipline Log covers session limits, stop rules and the record that keeps you honest.
If you want to see a Martingale streak for yourself, the roulette table here uses free play chips only. Nothing you win or lose is real money, which makes it the right place to watch a system fail.
Frequently asked questions
Does the Martingale work in the short term?
Most short sessions end with a small win, which is why the system feels like it works. The rare losing session wipes out many winning ones, and on average you lose the house edge on everything you stake.
Would a bigger bankroll fix it?
A bigger bankroll makes busting less frequent but makes each bust bigger, and the table limit still caps the progression. The average loss per unit staked stays at 2.70% on a single-zero wheel.
Is the Martingale illegal?
No. Casinos are happy for players to use it, because it does not change the house edge and it encourages large bets.
Should I bet on red after several blacks in a row?
It makes no difference. Each spin is independent, so red has the same 18 in 37 chance after ten blacks as after ten reds.
Is there any betting system that beats roulette?
No. Every bet on a fair wheel carries the house edge, and no sequence of bet sizes can add up bets with a negative expectation into a positive one.
