Mind Reader

About the Game

Click the topics below for more info about Mind Reader. If you would like to learn more about the game or have comments, please, contact us!


  • Play a few fast anonymous games, don't worry about winning
  • Play some anonymous games where you use the cheat button a little to win
  • When signed in with Facebook don't cheat, give up, or run out of time.


  • The bot makes decisions based on your previous moves, don't be too repetitive
  • The bot does not remember previous games, don't worry about repeating a strategy
  • The bot is somewhat random, a strategy will not yield the same results every game


  • Using a random number generator wont help you win
  • Counting in binary has proven to be useful for some people
  • Try switching strategically between very predictable sequences
Mind Reader is part of an ongoing research project at UC San Diego. The game has a wonderfully rich history. It was conceived in the 1950's by "The father of information theory" Prof. Shannon and D.W. Hagelbarger while the two of them worked at Bell labs. Both scientists built their own mind reading bot, and as legend has it, they had their bots compete against each other. Shannon's bot won, by a margin of 55 to 45.

Papers by Shannon and Hagelbarger describing their bots:
  • Shannon's Paper
  • Hagelbarger's Paper

  • The idea of making Mind Reader an online game belongs to Prof. Yoav Freund and Prof. Robert Schapire. They developed the first version of the Mind Reader game, upon which this current website is based. The modern version of Mind Reader uses hedging algorithms and context-weighted trees. Future work involves combining various kinds of 'experts' to create an even more difficult bot!

    The papers below describe our bot's strategy:
  • Context Tree-Weighting Method
  • Using Expert's Advice
  • Putting it Together

  • Questions, Glitches, or Comments?

    Please feel free to contact us about anything! We're happy to answer questions and are always looking for ways to make the website better. The best way to reach us is by becoming a member of our Facebook group. You can then post a comment on the wall. We'll make sure to read all comments and write responses in a timely manner.