Leela Chess Zero Blog

Chess.com Computer Chess Championship stage 2 has finally ended. After a 280 games battle only the top 2 engines will continue to the superfinal.
Stockfish and Houdini for a 200 games “fight”. Well no one really expects it would be a fight and Stockfish will probably win this by a huge margin.

The release candidate of a new Leela version has been released:

v0.18.0-rc1

We expect testing phase to last around 7-10 days, after which proper v0.18.0 will be released.

Download and full changelog here. Please test it thoroughly and report any bugs that you find.

Leela Chess Zero is a project started before some months inspired by Deepmind’s papers about AlphaGO Zero and AlphaZero, which is based on a new paradigm of Chess engines by not using traditional AlphaBeta search with handcrafted evaluation function but uses a variant of MCTS search called puct and for evaluation function it uses a self-taught neural network that learns by deep learning methods by playing against itself million times.

Stage 2 continues with Leela doing excellently being 3rd, half a point ahead of Komodo! **
Stockfish** continues its unbeaten run, being the only engine with no loss, stage 1 and 2 combined!

Stage 2 of CCCC has already started before 2 days. Not without problems initially with repeating restarts but at last now it’s running flawlessly.
Stockfish continues to be invincible! As it hasn’t lost a single game in the first 46 games of stage 1 plus the 15th till now in stage 2.
While the so far unbeatable too Komodo, in this stage lost to Houdini.

1st stage is almost over, 1 round remains but the top 8 engines that will participate in stage 2 are known.
Stockfish, Komodo, Houdini, Leela, Fire, Ethereal, Andscacs and Boot promote to next round.
Next round, unlike this round, would be without pondering and every engines will play every other 10 times so we would have a total of 70 games per engine.

While test20 runs, we are running test30 in parallel to test two ideas. First test30 uses a different method to initialize the first random net, and a slightly different LR (Learning Rate) strategy for the first few nets. The idea is to see if this eliminates the large spikes seen in some key metrics – policy loss, mse loss, reg term (see our expanded glossary).

In CCCC there have been played some very nice games and moves till now.
Can you find them? Play the move on the board and if it’s correct it will show the game continuation with a comment. If not, go back with arrows and try again or press show solution if you can’t find it.

CCCC continues and Leela , along with Stockfish , Houdini , Komodo and Fire , already has secured a place in the 2nd stage.
Ethereal after a strong finish, mainly winning in the last games, has almost secured the promotion. Booot has also many chances.
While Shredder and Andscacs are the ones that are competing for the final 8th place right now with Shredder to be ahead, but having difficult opponents to face in the next 4 rounds.

First round CCCC approaches to its end and situation is clear by now.
Houdini, Komodo and Stockfish will be in top 3 advancing to stage 2, with Stockfish and Komodo to fight for the 1st place in this 1st stage, thatdoesn’t mean much anyway, Fire and Leela would most probably advance to the next round also with some minor chances of not achieving it, and Shredder, Booot, Ethereal and Andscacs will fight for the other 3 places for stage 2.