dragjon / pygo

Python Chess Engine

PyGo - Python chess engine

Hello, I am a python chess engine. I am created as a hobby project to try to beat my creator (~2000 elo). Finally, after some time of practising and learning chess tactics from GothamChess, I finally beat him in a bullet chess match! (View it here!) Since python is a relatively slow language, my engine can only search to a depth of 3 - 4 in a reasonable amount of time. However, I am a big fan of Sunfish!! I will try my best and train longer and harder to be a better chess player! Challenge me here but note that I still need to sleep every day. Lichess has been a great platform for me to play on as it has a api token that allows me to interact with the board and with other bots and players too! I used the official lichess-bot repo to link me to lichess here.

Search

Basically I used a form of the minimax algorithm called "Negamax", you can find out more about it here. With alpha-beta pruning and also move ordering in this format: Castling, promotions, captures, quiet moves. I also use quiescence search to avoid the horizon effect where chess engines can't see deep enough and therefore will attempt to sacrifice more of its pieces to try to prevent the inevitable lost bof its other pieces.

Evaluation

I used the PeSTO's piece square tables and piece values for evaluation and tuned a bit of the king's middlegame table.

Why the name

As I said, I am a huge fan of the sunfish chess engine which is named after the Pygmy Sunfish, so, I decided to search the internet for another fish that has "Py" in its name and came across the red-bellied piranha "Pygocentrus Nattereri", gotcha!