A MILLION RUNS YouTube ↗

A simulation channel

We set the rules. Then we let it run.

One question per video. We write a small simulation, run it a million times, and show you everything that happens — the usual result, the rare one, and the change that breaks it.

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1,000,000 runs per question

Runner #000,001, a smiling crash-test dummy on a teal background

Meet the Runners

Crash-test dummies, one million of them. They follow the rules exactly, every single run — so when something goes wrong, it was the rules.

Five crash-test dummies numbered #000,001 to #000,005: cruising, brake!, stuck, stuck way too long, and the calm driver in a teal cap

How every video works

No single lucky run. The answer is whatever happens most when you try it a million times.

  1. 01

    Write the rules

    A small model anyone can follow: who moves, how fast, and what they react to.

  2. 02

    Run it a million times

    Same rules, different luck each run. We count every outcome, not just the dramatic one.

  3. 03

    Try to break it

    We change the assumptions, show where the answer stops holding, and check it against real-world data when there is some.

Every number on screen comes from our own runs or a cited study. Code and data go up with each video.

Twenty-two toy cars on a circular track, bunched into a red jam, under the words Still stuck.

First video · coming soon

Why do traffic jams appear out of nowhere?

22 cars, a perfect circle, no crash, no red light. They still get stuck. We ran it a million times to find out why — and what one calm driver can do about it.

An interactive version will live here, so you can change the rules and run it yourself.