Punichess

February 18, 2026 #chess #claude

I am really bad at chess… I blunder everything, and my opponents are barely better : our game evaluations are high frequency oscillators.

Anyway, “I” built a bot, I mean Claude built it under my supervision and guidance.

The objective is for it to make mistakes on purpose, but human makeable mistakes, not just sacrificing all it’s pieces, so it tries to find moves in which it loses a significant advantage. Similarly it tries to find moves which could enable a checkmate and blunders them on purpose.

Nevertheless for each blunder I make it magnanimously suggests blowing me to smithereens… so I can hopefully see that it was indeed a bad move.

Anyway it’s online, options are tweakable, defaults are all made by Claude, all is stored locally. It’s available at punichess.toby.re, if you are as bad as me, maybe it can help you out.

The code is provided under GPL-3 license (because I’m reusing GPL-3 code) and is available on github toby-bro/punichess Feel free to open issues if you want to see anything change.