Monte Carlo, 1913

On August 18, 1913, at the Casino de Monte-Carlo, the roulette ball landed on black 26 times in a row. Gamblers lost millions betting on red, sure the streak "had to" end. Each spin they doubled down, and each spin black came up again.

For European roulette (18 black, 18 red, 1 green), the odds of 26 straight blacks are about 1 in 137 million. Wildly improbable — yet with thousands of wheels spinning millions of times a day for decades, a streak like this is bound to happen somewhere, sometime. The gamblers' core error was treating each spin as linked to the last.