Many small wins, one huge loss
With a 100-unit bankroll and a 1-unit base bet, a cycle (playing until you win) earns 1 unit unless you hit seven losses in a row. That works about 99% of the time. In the remaining 1% or so you lose nearly everything.
| Cycle outcome | Approx. probability | Result |
|---|---|---|
| Win within the first 6 spins | about 98% | +1 unit |
| 6 losses, then win the 7th (all-in) bet | about 0.9% | about −26 units |
| 7 losses | about 0.9% | −100 units (bust) |
Multiply and add, and the average per cycle is negative. Win rate (how often you win) and expected value (average result) are different numbers, and the Martingale trades a higher win rate for a much bigger loss when it fails.
Bust rate by bankroll
Same conditions as the app’s Stats tab (European wheel, base bet of 1 unit, no cash-out goal, at most 3,000 spins per run), 4,000 runs each:
| Bankroll | Bust within 3,000 spins | Spins until bust (median) |
|---|---|---|
| 100 units | about 96% | about 175 |
| 500 units | about 79% | about 620 |
| 1,000 units | about 67% | about 925 |
| 100 units, American wheel | about 98% | about 150 |
Simulation figures use the app’s rules (always bet red, double after a loss, reset after a win), run thousands of times. Re-running shifts them by a point or two.
A bigger bankroll delays ruin; it does not remove it. Runs that survive 3,000 spins meet the same streak eventually if they keep going.
Nobody knows when
With identical settings, one player busts in a few dozen spins and another lasts over a thousand. The long survivors feel the system works and tell everyone; the people who went bust rarely post about it. That is survivorship bias.
Using the Stats tab
The app shows amounts in Korean won (₩) in every language. Treat them as abstract units; only the ratios matter.
Set up and run
On the Stats tab choose the bankroll, base bet, roulette type, table limit and cash-out goal, pick the number of runs (100, 500, 1,000 or 2,000) and tap Run Stats.
Read the bust rate and the distribution
The results show how many runs went bust, the bankruptcy rate, average and median spins survived, average peak balance and a histogram of survival spins. Each run stops at 3,000 spins, so the rate means “bust within 3,000 spins”.
FAQ
My peak was above my starting bankroll. Why not stop there?
You only know it was the peak afterwards. For the limits of stopping at a preset target, see the cash-out goal trap.
What if I raise the base bet?
With the same bankroll you survive fewer losses and bust sooner. Change only the base bet on the Stats tab and compare.
Martingale Bust - Roulette Sure-Win Simulator
Every amount is virtual. No sign-up, works offline. A free Android app for learning probability, in English and Korean.