Gambling terms, explained straight

Odds, Probability & Bankroll

Martingale system blackjack

A betting method in blackjack where the player doubles the stake after every losing hand, so that the first win recovers all previous losses and returns a profit equal to the original bet.

Betting rule
Double the wager after every loss until a win occurs.3
Bankroll targets
Convenient bankroll-to-goal ratios are one less than a power of 2: 7, 15, 31, 63, 127, 255.1

Key points

  • Each losing hand doubles the next bet; a single win recovers all previous losses and nets the original stake.3
  • A long losing streak can exhaust the bankroll before a win arrives, making the system risky in practice.4
  • The martingale system is applied to even-money bets in blackjack, not to all hands or side bets.2

Where this term is used

Not the same as

  • Martingale strategy — a broader name for the same doubling system, but in mathematics it also refers to a stochastic process unrelated to gambling
Odds & probability Blackjack house edge Explains the built-in casino advantage in blackjack that the martingale system cannot overcome. Odds & probability Martingale strategy roulette Covers the same doubling system applied specifically to roulette even-money bets. Odds & probability Bankroll management blackjack Discusses how to size bets and preserve funds, a key concern when using the martingale system. Odds & probability Kelly criterion blackjack Describes an alternative bet-sizing method that optimises growth rather than chasing losses. Odds & probability Risk of ruin blackjack Quantifies the probability of losing an entire bankroll, a central risk of the martingale system. Odds & probability House edge baccarat vs blackjack Compares house edges across games, relevant when choosing where to apply a betting system.

Sources

  1. Martingale (betting system) en.wikipedia.org Provides the definition and the bankroll-to-goal ratio examples.
  2. Labouchere Betting System wizardofodds.com Confirms the system applies to even-money betting contexts.
  3. Gambling Glossary wizardofodds.com Supports the doubling-after-loss rule and the mechanics of the system.
  4. Martingale Betting System wizardofodds.com Explains the risk of bankroll exhaustion and the system's practical limitations.

Sources are drawn from regulators, universities and published research, and each one is labelled with what it actually is — a preprint is not called a paper. Bookmaker and affiliate pages are never cited here, because a page that sells betting is not a neutral authority on it.

Written and maintained by Ellis Warrender, writer and maintainer.

Last updated 28 July 2026. Spotted an error? Tell me and it gets fixed and logged on the corrections page.