Caged Brain - Can Computer Predict Your Next Move? 🧠 vs 🤖

AI Predictions with Simple Statistical Methods

Greg Surma
6 min readApr 22, 2019


In today’s article, we are going to build a prediction system with simple statistical methods. We are going to show that Machine Learning applications aren’t limited to neural networks only and we can achieve a decent predictive behavior with Computational Statistics. By the end of this article, you will be able to implement a very basic, yet impressive prediction system.

Caged Brain - simple prediction game


Caged Brain project was heavily inspired by Scott Aaronson’s Oracle:

In a class I taught at Berkeley, I did an experiment where I wrote a simple little program that would let people type either “f” or “d” and would predict which key they were going to push next. It’s actually very easy to write a program that will make the right prediction about 70% of the time. Most people don’t really know how to type randomly. They’ll have too many alternations and so on. There will be all sorts of patterns, so you just have to build some sort of probabilistic model. Even a very crude one will do well. I couldn’t even beat my own program, knowing exactly how it worked. I challenged people to try this and the program was getting between 70% and 80% prediction rates. Then, we found one student that the program predicted exactly 50% of the time. We asked him what his secret was and he responded that he “just used his free will.”

Scott Aaronson, Quantum Computing Since Democritus.

Caged Brain

We are going to build a predictive system encapsulated in a very simple game. While the user, is going to pick either ‘LEFT’ or ‘RIGHT’, the computer is going to analyze user’s moves and predict the next one. User’s goal is to be unpredictable and make computer fail in its predictions (green color). The lower the computer’s prediction % the better!