Does the Martingale strategy work? No — here's the exact math.

Doubling your bet after every loss feels like it should eventually guarantee a profit. It doesn't, and the reason isn't intuition — it's arithmetic you can check yourself, plus a live simulator that proves it over a thousand sessions at once.

Published August 21, 2026 · RTP Lab

01 / What Martingale actually is

Double after every loss, reset after every win

The system: bet a fixed base amount. Lose, and you double the next bet. Win, and you drop back to the base amount and start over. The logic is that a single win anywhere in the sequence recovers every prior loss in that streak plus one base bet of profit — which is true, as far as it goes. The problem is what it costs to get there, and what happens on the streaks that don't end in time.

02 / The proof

Expected value doesn't care about bet sizing

Sum the expected value across an entire Martingale sequence — every possible length, weighted by how likely each length is — and it collapses to exactly (RTP − 1) × total amount staked, the identical formula that applies to flat betting the whole way through. Bigger bets later in the sequence multiply both the potential win and the potential loss by the same factor, which is precisely why they cancel out in expectation. No sequence of bet sizes changes the edge — only flat-out avoiding the game does that.

03 / The real risk

Bankroll requirements explode faster than most people expect

A losing streak's probability doesn't need to hit zero to end a Martingale run — it just needs to outlast either your bankroll or the table's bet limit. Here's what that looks like at a clean 50% win chance (a Dice roll-under-50 bet), where base bet = 1 credit:

Losing streak	Chance of this streak	Bankroll needed
5 in a row	3.125%	31× base bet
7 in a row	0.781%	127× base bet
10 in a row	0.098%	1,023× base bet
13 in a row	0.012%	8,191× base bet
15 in a row	0.003%	32,767× base bet

Bust chance = (1 − win chance)^streak length. Bankroll needed = base bet × (2^streak length − 1). Computed live from the win chance itself, not a lookup table.

A 15-loss streak at a coin-flip win chance happens about 3 times in every 100,000 sequences — rare, but nowhere near impossible over a real playing history — and by then you'd need over 32,000× your base bet sitting in reserve just to place the next bet. Most table and platform bet limits cap out long before that, which turns "the streak eventually ends" into "the streak ends the session for you first."

04 / Test it yourself

A live simulator, not just an assertion

The Martingale tester

This site's Martingale tester runs 1,000 full doubling sequences client-side for whatever bankroll, base bet and target you configure, and reports the bust rate and average outcome. Run it at a few different bankroll sizes and watch the bust rate climb sharply once the bankroll can no longer cover the streak lengths in the table above — a live demonstration of this same math, not a separate claim.

05 / FAQ

Quick answers

Does Martingale work over the short term?

It can "work" for a while, in the sense that most short sessions end in a small win before a long losing streak hits — that's exactly the trap. It doesn't change the underlying math, it just front-loads the wins and back-loads a rare but severe loss.

Do professional gamblers use Martingale?

Not as a genuine edge strategy — it's well understood in gambling and quantitative finance circles as a system that trades frequent small wins for rare catastrophic losses, with no improvement to expected value.

Can casinos ban you for using Martingale?

We're not aware of platforms banning a specific bet-sizing pattern within normal terms — it's legal, if mathematically ineffective. Table or bet limits are the real constraint that ends most runs.

Is there a betting system that does beat the edge?

No. Every bet-sizing system redistributes when wins and losses happen — none of them touch the underlying probability or payout, which is where the edge actually lives. See what house edge actually means for why.

06 / Read more