[ThinkBetter](https://thinkbetter.app/) → [Cognitive Biases](https://thinkbetter.app/cognitive-biases.md) → Gambler’s Fallacy

# Gambler’s Fallacy

The mistaken belief that if something happens more frequently than normal during a given period, it will happen less frequently in the future, or vice versa.

![Gambler’s Fallacy illustration](https://assets.thinkbetter.app/images/gamblers_fallacy.png)

The Gambler’s Fallacy, also known as the Monte Carlo Fallacy, arises from the incorrect belief that if something happens more frequently than normal during a given period, it will happen less frequently in the future, or vice versa. This fallacy was famously highlighted during a game of roulette in the Monte Carlo Casino in 1913, where the ball fell on black 26 times in a row, causing gamblers to lose millions betting on red under the assumption that it "had to come up" eventually. The fallacy lies in the mistaken belief that independent events in games of chance, like flips of a coin or spins of a roulette wheel, are somehow interconnected and that future probabilities are altered by past events. This fallacy is a cognitive bias and a misunderstanding of probability.

## Example

**Casino Betting**

A person continues to bet on red at a roulette table because black has come up several times in succession, believing that red is "due" to appear next. Why? This belief in a balancing out of outcomes, despite each spin being independent, exemplifies the Gambler’s Fallacy.

## In your professional life

**Maintain Optimism in Every Interaction**

In sales or customer service roles, approach each interaction with renewed optimism, regardless of previous outcomes. For example, if you’re a sales representative and have faced multiple rejections, start each new call or meeting with a positive attitude. This mindset helps you stay motivated and engage effectively with each customer, increasing your chances of success.

## Go deeper in ThinkBetter

The ThinkBetter app has the full Gambler’s Fallacy deep-dive: more examples, a quiz to test yourself, audio narration, and a weekly path that builds these ideas into a habit.

- iOS: https://apps.apple.com/app/id6459831884
- Android: https://play.google.com/store/apps/details?id=io.ventureship.braintricks

### Related concepts

- [Illusion of Control](https://thinkbetter.app/cognitive-biases/illusion-of-control.md)
- [Regression to the Mean (Mental model)](https://thinkbetter.app/mental-models/regression-to-the-mean.md)
- [Probabilistic Thinking (Mental model)](https://thinkbetter.app/mental-models/probabilistic-thinking.md)
- [All mental models](https://thinkbetter.app/mental-models.md)

Page: https://thinkbetter.app/cognitive-biases/gamblers-fallacy