Real or fake?

Two strings of coin flips: one real, one made up by a person. Tap the fake. As many as you can in 60 seconds, each one scored the moment you answer.

How it works

1. Each round shows two strings of coin flips. One came from a fair coin; a person made up the other. Tap the fake.
2. A right pick scores 10; a wrong one costs 3. People switch sides too often and avoid long runs.
3. Rounds get harder as you improve: the fakes look more and more like the real thing.

It trains spotting real randomness. After every round you see the best answer and why.

Play real or fake?

Play with friends or a club

Challenge a friend with a duel link, or run a tournament for a club or class: one link, the same rounds for everyone, one run each, and a live leaderboard.

Also try Make a market, or the probability puzzles.