Martingale doubles the stake after every loss and returns to the base bet after a win. It wins one base unit per cycle with high probability, until a losing streak meets the table maximum or the bankroll. The lab above has already run 1,000 seeded spins; press Space to rerun or R for a new seed.
Watch two things on the chart: the dashed EV line, which falls by 2.7% of everything wagered, and the moment the balance line drops off a cliff. Switch on Monte Carlo to see 60 alternate futures with the same settings and count how many of them end at zero.
Open this experiment in the lab ↑All numbers below were computed by the same simulator and models that run in the lab above, when this page was built.
Every bet in roulette has a negative expectation. A betting system changes how stakes are distributed over time, not the edge per coin wagered.
400 simulated sessions of 1,000 spins with a 1,000-coin bankroll and a 10-coin base unit: 343 went bankrupt (85.8%). The median session ended at 0 coins.
With a 10-coin base unit and a 5,000-coin table maximum, Martingale needs a bet above the limit after 9 consecutive losses. By then 5,110 coins have been staked on the streak. Chance that a 1,000-spin session contains at least one streak of 9 losses: 70.3%.
400 sessions per strategy, 1,000 spins each, 1,000-coin bankroll, 10-coin base unit, 5,000-coin table maximum, European wheel (2.70%). The same 400 seeds are used for every strategy.
| Strategy | Survived | Median final | Mean final | Avg wagered | Expected loss | Observed loss | Avg longest losing streak |
|---|---|---|---|---|---|---|---|
| Flat bet | 98% | 740 | 724 | 9,980 | 270 | 276 | 9.6 |
| Martingale | 14% | 0 | 670 | 13,510 | 365 | 330 | 7.7 |
| Fibonacci | 25% | 0 | 659 | 13,957 | 377 | 341 | 8.3 |
| D'Alembert | 7% | 0 | 307 | 25,353 | 685 | 693 | 7.5 |
| Labouchère | 3% | 0 | 335 | 22,497 | 608 | 665 | 6.2 |
| James Bond (7.0 / 2.5 / 0.5) | 100% | 738 | 719 | 10,000 | 270 | 281 | 5.9 |
No. Each spin keeps the same negative expectation, so the expected result of a session is minus the house edge times the total amount wagered. Martingale converts many small wins into rare, very large losses.
Doubling grows exponentially. With a 10-coin base bet, nine losses in a row already call for a 5,120-coin tenth bet. When the table cap or your bankroll stops the doubling, the whole streak is lost at once.
Yes. The seed, strategy, bankroll and bet are stored in the URL. Use the Share experiment link button and anyone who opens the link sees the same spins.
No. The lab uses virtual coins with no cash value. There are no deposits, withdrawals or prizes. 18+.
Free-to-play entertainment and math education with virtual coins only. No real money, no deposits, no withdrawals, no prizes. 18+. Simulated results do not predict real outcomes.