The El Farol Bar Problem

A famous puzzle about crowds, prediction, and why there's no such thing as a strategy everyone can share.

There's one popular bar, El Farol. 100 people each independently decide, every week, whether to go.

• The bar is fun only if it's not too crowded — specifically, if 60 or fewer people show up.
• If more than 60 show up, it's miserable — everyone who went wishes they'd stayed home.
• If 60 or fewer go, they have a great time — and the people who stayed home wish they'd gone.

Everyone decides at the same time, with no communication, based only on how crowded it's been in past weeks.

Is there a single "best strategy" that everyone could follow to reliably predict whether to go?