Do Betting Systems Work? Martingale, D'Alembert and the Rest
6 min read · updated 2 September 2026
A betting system is a rule for changing your stake based on recent results. Martingale doubles after a loss; D'Alembert nudges up one unit after a loss and down one after a win; Fibonacci walks up a sequence; Paroli presses winners instead of losers; Labouchère crosses numbers off a list. They are marketed as ways to beat games you cannot beat.
None of them works in the sense people hope. Here is what they actually do.
Why no staking plan changes the edge
If every individual bet has negative expected value, then any weighted sum of those bets also has negative expected value. That is a mathematical fact, not an empirical one — you cannot combine losing bets into a winning strategy by choosing the sizes cleverly.
A system can change when you bet and how much, but it cannot change the fact that each spin of a roulette wheel returns, on average, 97.3 pence per pound staked on a single-zero wheel. Multiply that by any staking schedule you like and the average stays below break-even.
What each system actually does
Martingale wins a small amount on most sessions and loses everything on a rare one, when a run of six or seven losses pushes the next bet past the table limit or your bankroll. Its distribution is a thin sliver of small wins and a fat tail of catastrophic losses.
D'Alembert and Fibonacci are gentler versions of the same idea — increase after losses — so they bust less violently but still bleed the edge and still have a losing tail. Paroli inverts it, pressing wins, which produces many small losses and occasional larger wins: the mirror image of Martingale. Flat betting, which is not really a system, gives the widest and most symmetric spread of outcomes.
The table limit is not the problem
People often blame Martingale's failure on table limits, imagining that with an unlimited table and bankroll it would work. It would not. Even with infinite resources, the expected value of the strategy is still negative — you would win 1 unit almost every session and, in the sessions you lose, lose an unbounded amount, and the maths of that still comes out negative.
When systems are fine
If you understand that a system only reshapes a fixed expected loss — trading a wider spread for a narrower one, or many small wins for one big loss — and you bet money you are happy to lose for entertainment, there is no harm in using one. The harm comes from believing it has turned a negative-expectation game positive, and staking accordingly.
FAQ
- Does the Martingale system work?
- No. It wins small on most sessions and loses your whole bankroll on the rare long losing streak, which happens far more often than people expect. The average result is still a loss equal to the house edge times everything you staked.
- Is D'Alembert safer than Martingale?
- It busts less abruptly because stakes rise linearly rather than doubling, but it has the same negative expectation and still has a losing tail. Safer ride, same destination.
- Can any system beat roulette?
- Not a staking system. Only a physically biased wheel or a dealer signature — something that changes the probability of each number — can beat roulette, and casinos work hard to eliminate both.