The Gambler’s Fallacy – What It Is and How to Avoid It

Ian Bruce

Senior Editor

Updated: 13 May 2024

The Gambler’s Fallacy is a form of cognitive bias. It leads a bettor to believe that an outcome has a greater chance of happening than it really does. In this guide, we explain how this common fallacy works, why it is dangerous, and how you can avoid falling for it.

Gambler’s Fallacy Explained

This particular bias, which is also referred to as the Monte Carlo fallacy, is widespread. In fact, if you don’t have it yourself, you’re certain to know someone who does. To find out if you have it, consider the following scenario:

A coin is tossed seven times. On each toss, the coin shows Heads. Now, if you were asked to bet on the next toss of the coin, would you bet on Heads or Tails showing? Most people would choose to side with Tails. That’s because they have fallen for the Gambler’s Fallacy. They believe that, with Heads already having shown up seven times in a row, Tails is now much more likely to show up on the eighth toss of the coin.

Of course, that isn’t the case at all. The odds of Heads or Tails showing on any honest coin toss are always the same. But our human brains can’t help believing that the preceding results in some way have an influence on the results to come.

Gambler’s Fallacy Example

Let’s give you a real-world example of the Gambler’s Fallacy in action. We’ve said that it is also known as the Monte Carlo fallacy, and that’s because of something that happened at the Casino de Monte Carlo in 1913. On that occasion, a series of black numbers started winning at the roulette wheel. There were five black numbers in a row, then six, then seven.

The gamblers at the wheel soon started betting on red, with increasing certainty that a winning red number was just a spin or two away. But it wasn’t. The sequence of black numbers extended to 10, 15, 20 and more. The streak of black numbers eventually extended to 26 in a row, and the people who were betting on red lost millions.

Hot Hand Fallacy

When a run of results happens to be going in your favour, you could just as easily fall for the Hot Hand Fallacy. This is where the previous results lead you to believe that you’re on a ‘lucky streak’ and that you have more chance of winning than you really do.

Consider someone who rolls a die and bets on the number shown being odd. He rolls an odd number three times in a row and begins to feel that Lady Luck is on his side. He might then respond to his betting bias by deciding to increase the size of his subsequent bets to try and make the most of his ‘purple patch’.

If this streak were to continue, his false belief that his chances of winning are particularly favourable would only get stronger, and he might continue raising his stakes as a result. But, once again, his belief has no basis in reality. The odds of him winning or losing on the next roll of the dice are always the same, no matter how successful his previous rolls were.

Why the Gambler’s Fallacy is Dangerous

Now that you are familiar with the Gambler’s Fallacy meaning, it should be quite clear that it is something potentially dangerous. That’s because it leads people to bet with the false assumption that an event is more likely to happen than it really is.

Both of these positions are wrong because they are based on false assumptions. Watching five favourites in a row lose their races doesn’t give the sixth favourite a better chance of winning. And seeing a football team win four matches in a row won’t improve their chances of winning the fifth. Sure, they might have a bit more confidence, but they still need to be better than the opposing team on the day of the match, and that’s never guaranteed.

In short, the Gambler’s Fallacy is dangerous because it leads people to bet on false assumptions and often to bet with larger amounts than the outcome warrants.

Conclusion

The Gambler’s Fallacy is something that all of us seem to be hard-wired to fall for. According to the BBC, even monkeys fall for it. Fortunately, human beings can use reason and rationality to recognise this cognitive bias and avoid it, and we advise all bettors to do just that.

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Ian Bruce

Senior Editor

Ian Bruce joined Safest Betting Sites in 2024 as Senior Sports Editor to oversee the quality and usefulness of its gambling content. He originally developed an interest in betting after landing a winning Yankee on his first attempt. He then spent years figuring out how to replicate that success. Along the way, he became one of the UK’s leading writers on the topic of betting and gaming. Ian’s career has now spanned more than three decades, and his enthusiasm for systematic and responsible betting hasn’t waned one bit. However, his preferred approach to winning these days is Dutching, for the simple reason that “It’s a lot easier than landing Yankees.”

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