About Paper Soccer
Paper Soccer brings the pen-and-paper classic to your browser and your phone, with neural-network opponents at every level. Here is who makes it, how the AI works and how to reach us.
Who makes Paper Soccer
Paper Soccer is designed and built by Mateusz Kraśniewski, an independent developer who also publishes the Paper Soccer apps on the App Store and Google Play. The strategy and history articles on this site are his too.
How the AI works, in plain words
Every computer opponent is a small neural network: a program that learned to judge positions from experience instead of following a hand-written list of tactics.
It learned by self-play. Our own training engine made the network play game after game against itself and, after each batch, nudged it towards the moves that led to wins. Weaker and stronger levels use different snapshots of that training, look more or fewer moves ahead, and some add a little randomness so they make human-like mistakes.
The AI runs on your device: in this browser game and in the apps, its moves are worked out locally, not on a server.
The bot ladder
The apps have a ladder of 27 bots, rated from 100 to 1400 Elo in steps of 50 points. Each level's rating was measured in calibration matches against opponents with known ratings, not assigned by feel.
The weakest level is the coach in the apps' tutorial. The opponent in this browser game, Amateur Andy, is rated 500 Elo.
The browser game and the apps
This website is a free demo: one match against Amateur Andy, right in your browser, with no download and no sign-up.
The free apps for iOS and Android have the full ladder of 27 bots, puzzles, online matches against players worldwide and a local two-player mode on one device.
Contact
Questions, bug reports, ideas or press enquiries: write to info@paper.soccer.