Show HN: EvoChess – start with 8 pawns, evolve your army (penkovsky.github.io)

3 points by penkovsky ↗ HN
This chess variant's theme is evolution. One morning in early 2016 I woke up with an idea: what if chess were built around promotion? Eventually, this resulted in the following game:

It plays like chess, but you start with only pawns and a king. Pawns can be promoted to bishops or knights, while those minor pieces can be promoted to rooks. Their promotion rights accumulate (every three pawn moves, pawn promotion right; every three minor piece moves, minor piece to rook right). Rooks are transformed to a knight or a bishop on the rook's fifth move.

Recently, I built a playable version. The AI opponent works on phone with no internet. The search engine uses a lightweight neural net. The engine was first weak and my friends complained about it.

So I have spent quite some time to train a better NN for the board evaluation. Fixed some bugs in search. And I have even designed a "Fun" mode where the AI opponent is thinking while you are thinking. (WARNING: "Fun" mode is ruthlessly draining the battery)

Now, when the engine became stronger, my friends complain it is hard to beat. Is the Fun mode less fun now? Should I allow the engine to lose?

More in the writeup: https://penkovsky.com/post/evochess/

Code: https://github.com/penkovsky/evochess/

4 comments

[ 0.78 ms ] story [ 10.9 ms ] thread
Good game! The Ai is a little too difficult though, it could be an issue skill on my part XD Either way, great work.
I see a lot of people are losing, even on Easy (in fact, everyone). Thank you folks for giving a try. I appreciate even the silent feedback. I will release a new version with a more enjoyable opponent, especially for beginners, soon.
Fun game! I had a king and knight vs a king and the game automatically ended in a draw. I was looking forward to figuring out how to find checkmate with a rook promotion, but maybe it wouldn't have been possible before the demotion happened again?