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How Confirmation Bias Affects Your Poker Game

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I hope you enjoyed my first column on cognitive biases on selfish bias, follow up on curse of knowledge, then anchoring bias.

Let’s look at a bias you’ve probably heard of before, confirmation bias. It is our tendency to find or notice, and selectively recall information that confirms our pre-existing beliefs.

If you already think a politician is stupid, you’re more likely to notice their mistakes and gaffes, and more likely to remember those mistakes when you think about them. If you think they’re brilliant, you’re less likely to notice and remember their mistakes. As such, your opinion, which might have been formed early before you had sufficient evidence, is only reinforced and cemented by your misperceptions and inaccurate recall of later events.

In poker terms, you might form an early opinion of an opponent and then maintain that opinion despite later evidence to the contrary. If someone has raised the first five hands at the table, you might feel like they are loose and aggressive. Once that first opinion is formed, you might not notice how much they fold over the next few hours and you’ll still consider them a loose player.

It is clear that this kind of mistake is likely to cause you to play badly against them. If you are going to try to adjust your basic strategy based on your opponent (known as GTO play, see chapter 4 of my book FossilMan Winning Tournament Strategies), you must have a definite line on this opponent. Otherwise, your adjustments will be incorrect and cost you a lot of equity.

This bias also impacts us on smart strategy in general. If you’ve missed a bunch of flush draws, it’ll make you think you’re not hitting flush draws as often as you should. And that could cause you to play those draws incorrectly, based on that mistaken belief.

This is partly why it was so difficult for players to develop good strategies before computer analysis. It’s one thing to calculate how many times you would need to flush two cards to get hold’em. It’s another thing to determine if it’s more profitable to flat-call a raise when in position with AK, or if it’s better to re-raise. There are so many confusing variables that it’s nearly impossible to trust your memory and remember how well you’ve done in each game over thousands of tries, spanning months and years. Now add to that your confirmation bias that you thought a strategy was superior before you got the data, and you’re unlikely to know if your initial opinion is wrong.

Which leads to a related effect, selective memory. Selective memory is strongly linked to confirmation bias. Selective memory is the tendency to more clearly remember events that support an idea, value, or opinion, while simultaneously being less likely to remember events that contradict them.

If you’ve tried to play AK by simply calling, and other times by raising, you’ll probably have selective memory about the results. Confirmation bias only exacerbates this effect. If you expect the more passive line to perform better, you are more likely to selectively remember times when the passive line worked and selectively forget times when the passive line didn’t. not worked so well. If you expected the more aggressive line to be better, selective memory will probably lead you to believe it was better, regardless of the reality of what happened.

Confirmation bias and selective memory run counter to a well-understood concept. In other words, to find the truth accurately, you have to be honest with yourself and about yourself. We all struggle with this, both in poker and in every other aspect of our lives. It’s always hard to be honest with yourself. We all have flaws, most of us have many flaws, and some of them are quite serious. It is painful to face these defects. But if we can’t recognize our flaws, we can’t fix them.

The same goes for our poker game. If we can’t notice and recognize the flaws in our game, the mistakes we all make, then we don’t even know they need to be fixed. This is partly why these biases exist. Like many other prejudices, they protect our ego from reality. In the short term, they make us feel better about ourselves. But, in the long run, wouldn’t you rather make more money?

If you said yes, then you must learn to overcome all these prejudices. Only then can you truly know yourself, understand what you could do better, and become the best player you can be. It’s not easy to do, but if you do, it will have been worth all the effort and pain it took to get there.

Have fun and play smart! ♠

Greg Raymer is the 2004 World Series of Poker main event champion, winner of multiple major titles and has over $7 million in prize money. He is the author of FossilMan’s Winning Tournament Strategies, available from D&B Publishing, Amazon and other retailers. It is sponsored by Blue Shark Optics, YouStake and ShareMyPair. To contact Greg, please tweet @FossilMan or visit his website.