Leela Chess Zero Blog

The TCEC(Top Chess Engine Championship) tournament is currently running with engines playing in the premier division and this division will finish in a few days. But this time, after premier division end, there would not be an immediate starting of the superfinal between the top 2 placed engines in premier, but a new tournament is going to happen that Chessdom has announced, the TCEC CUP , with all engines of TCEC but in a different format, that of knockout games, one that brings in mind the traditional Cup competitions of football.
(TCEC superfinal will he held after the TCEC Cup of course)

Chess.com has [announced](https://www.chess.com/news/view/stockfish-houdini- to-battle-for-computer-chess-championship-komodo-vs-lc0-for-3rd) that after the CCCC superfinal between Stockfish and Houdini(Stockfish is ahead 27.5-20.5 till now) will finish, then 30 games of Komodo versus Leela will be played to determine the 3rd place.
This is a surprise since there were no such plans initially announced, but it is welcomed for Leela and Komodo fans. Probably Chess.com did it since Leela fan base is high and they want to take advantage of this.

The “Release Candidate 2” for the Lc0 version v0.18 has been published!
Available to download here.

Change:

• Fixed a severe race condition bug when only happened when –out-of-order-eval is on (which is the default value now).
  Could produce incorrect search results.

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).