The Palindrome

The Palindrome

Your Brain is Wrong About Probability

The universe doesn't remember your last coin toss

Tivadar Danka's avatar
Tivadar Danka
Jul 01, 2025
∙ Paid
20
2
3
Share

I precisely remember the first time probability finally clicked for me.

During the summer break of my undergrad first year, I had a brief crush on poker, spending most of my days either grinding the online microstakes no-limit Texas hold 'em tables or endlessly consuming poker theory books.

Poker is a beautiful game, and most of the lessons I have learned from it have had a significant impact on my life.

Only fight battles you are favored to win.

Winning one hand is luck. Winning a thousand is skill.

Losing doesn't mean that you made a bad decision. Winning doesn't mean that you made a good one.

To this day, I explain the concept of expected value with pot odds in poker. Someday I'll write a massive essay on the life-changing ideas that my short stint at the online casinos taught me, but right now, I want to talk to you about probability.

Let me tell you: our intuition about probability is fundamentally flawed, resulting in mostly comical, sometimes tragic situations.

This post is about three of them:

  • that misunderstanding probability can lead us to financial ruin,

  • that probabilities don't scale linearly,

  • and what can happen will happen eventually.

Speaking of poker: gamblers on a losing streak tend to keep on playing, as they perceive that their bad luck should increase the chance of winning.

Here's why this is wrong.

The gambler’s ruin

Let's play a simple game!

The dealer tosses a fair coin. If it comes up tails, you win $1. Heads, you lose $1.

Suppose that you lost ten times in a row. Does it increase the likelihood of winning the next round? Take your time to think it through; I'll even leave a couple of blank lines to keep you from spoilers.

.

.

.

Keep reading with a 7-day free trial

Subscribe to The Palindrome to keep reading this post and get 7 days of free access to the full post archives.

Already a paid subscriber? Sign in
© 2025 Tivadar Danka
Privacy ∙ Terms ∙ Collection notice
Start writingGet the app
Substack is the home for great culture