The gambler’s fallacy

Also known as the Monte Carlo fallacy · Probability & judgement

The gambler’s fallacy is the belief that past random events change the odds of future ones — that after a run of reds, black is "due." For independent events the probability resets every time; the coin has no memory.

By the ReadGlobe Editors · Reviewed 2026-05-29

Why does the gambler’s fallacy happen?

We expect even short sequences to look "representative" of randomness, so a streak feels like it must balance out soon. But independence means each trial is unaffected by the last.


The coin has no memory — a streak is a story imposed on noise that has none.

What does the gambler’s fallacy look like in real life?

  • Betting on black after five reds on roulette — the odds are still about 50/50.
  • Assuming a couple with four daughters is "due" a son.
  • Thinking a slot machine that hasn’t paid out is "about to."

How do you counter the gambler’s fallacy?


  • For independent events, ignore the streak — the odds reset every trial.
  • Ask whether the outcome actually depends on the previous one. Often it doesn’t.
  • Don’t confuse "an unlikely sequence" with "an unlikely next event."

The deeper point

The gambler’s fallacy and the hot-hand fallacy are mirror errors from one root: the gambler thinks a streak must break, the hot-hand believer thinks it must continue. Both impose a story on noise that has none.

Frequently asked


What is the gambler’s fallacy?
The mistaken belief that past independent random outcomes affect future ones — e.g. that black is "due" after a run of reds. The odds actually reset every spin.
Why is it called the Monte Carlo fallacy?
After a 1913 Monte Carlo casino night when roulette landed on black 26 times in a row; gamblers lost fortunes betting on red, certain it was "due."
How is it different from regression to the mean?
Regression to the mean is real — extremes tend to be followed by averages. The gambler’s fallacy is false — it wrongly assumes independent events "balance out" in the short run.

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The book behind this idea: Thinking, Fast and Slow by Daniel Kahneman. Hear the whole thing free — start an Audible trial and your first audiobook is on the house.

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APA

ReadGlobe. (2026). The gambler’s fallacy. https://readglobe.com/bias/gamblers-fallacy/

MLA

"The gambler’s fallacy." ReadGlobe, 29 May 2026, readglobe.com/bias/gamblers-fallacy/.

Primary source: Wikipedia

Editorial synthesis © ReadGlobe 2026, drawing on Kahneman’s Thinking, Fast and Slow, the Tversky–Kahneman research program, and the primary cognitive-science literature. · Last reviewed 2026-05-29.