The most famous betting "system": after every loss, double your bet, so one win recovers everything plus one unit. It feels unbeatable. Run it below and watch what a finite bankroll and a table limit actually do to it.
This is the whole point of EV Lab: no system beats the edge. See it live on every bet — for free, no signup.
▶ Play the games — no signupEach individual bet keeps its negative expected value — doubling the stake doesn't change the odds, it only changes the size of the swing. The system converts a stream of small, likely wins into a rare, catastrophic loss. Two hard walls make that loss inevitable: your bankroll is finite, and casinos set a table maximum precisely so a doubling run can't continue forever. The longer you play, the more certain you are to hit a losing streak that breaks through both. When you do, a single streak erases every small win you banked — and then some.
On a true 50/50 bet with no limits and infinite money, Martingale would "work" in the mathematical limit. Those three conditions never exist at once. Change the house edge field to 50% and remove the cap to see the difference — and notice that even then you're risking a fortune to win a single unit.
Does any betting system beat the house? No staking system — Martingale, d'Alembert, Fibonacci, Labouchère — changes a game's expected value. They only reshape variance: how your inevitable loss is distributed over time.
So what actually matters? The house edge per bet and how much total you wager. Lower edge and fewer bets lose you less. The only bet with zero expected loss is the one you don't make.