Getting Started

Basics

Lc0 has three main parts:

NAME	FILE	Function	Needed for Contributing	Needed for Playing
Engine	lc0.exe	Does the tree search and calls the NN to get evaluations	YES	YES
Network (NN)	Varies e.g. weights_run1_20703.pb.gz	Stores the Neural Net's evaluation function	YES	YES
Client	client.exe	Gets the latest network from the server, generates self-play games, and uploads the training data to the server	YES	NO

• To help the project by donating GPU time, you need all three of these, and you should run client.exe. The client will automatically run lc0.exe, and ask the server what to do. If this doesn't work right away try debugging by running lc0.exe (see Debug section below).

• To play or analyze games with Lc0, you don't need client.exe, just run the engine lc0.exe with a strong network file. The best way to do this is using a chess GUI, see the guide in our blog.

Downloading

Client

Can be downloaded from https://github.com/LeelaChessZero/lczero-client/releases

• Windows --> client.exe
• Linux --> client_linux
• Mac --> client_mac

Engine

• Mac/Linux --> must be compiled by user (refer to the README.md in github )
• Windows --> download the latest from https://github.com/LeelaChessZero/lc0/releases
  • CPU only : lc0-windows-blas.zip
  • Nvidia GPU : lc0-windows-cuda-zip
  • Very recent Nvidia GPU (e.g. 2080Ti) : lc0-windows-cuda10.0-cudnn7.3-for-2080.zip
  • Other GPU cases: lc0-windows-opencl.zip
• Changelog between different versions

Network

Download the latest network from http://lczero.org/networks

• e.g. weights_476.txt.gz
• Place in the same directory with lc0.exe

Debug

• For easier debug, verify install by running from command line (cmd.exe)
  • cd to directory with lc0.exe
  • run lc0.exe --logfile=log.txt
    • Most recent weights file in that directory will be used automatically.
    • Add --weights=c:\path\to\weights_476.txt.gz to specify manually.
  • Example expected output:

       _
|   _ | |
|_ |_ |_| built Jul  8 2018

• Type go nodes 100
• Example expected output:

go nodes 100
Found network file: C:\Users\aolsen\Desktop\Engines\lc0-win-20180708-cuda92-cudnn714/weights_476.txt.gz
Creating backend [cudnn]...
info depth 2 seldepth 2 time 28 nodes 2 score cp 21 hashfull 0 nps 71 pv c2c4 g8f6
info depth 2 seldepth 3 time 39 nodes 4 score cp 19 hashfull 0 nps 102 pv c2c4 e7e5 g2g3
info depth 2 seldepth 4 time 56 nodes 15 score cp 20 hashfull 0 nps 267 pv c2c4 c7c5 g1f3 g8f6
info depth 2 seldepth 5 time 73 nodes 34 score cp 20 hashfull 0 nps 465 pv c2c4 c7c5 g1f3 g8f6 b1c3
info depth 2 seldepth 6 time 92 nodes 73 score cp 20 hashfull 0 nps 793 pv c2c4 c7c5 g1f3 g8f6 b1c3 e7e6
info depth 2 seldepth 7 time 111 nodes 121 score cp 20 hashfull 0 nps 1090 pv c2c4 c7c5 g1f3 g8f6 b1c3 b8c6 d2d4
info depth 2 seldepth 7 time 114 nodes 121 score cp 20 hashfull 0 nps 1061 pv c2c4 c7c5 g1f3 g8f6 b1c3 b8c6 d2d4
bestmove c2c4

• type quit to exit the program.
• Common problems
  • lc0.exe exits without printing anything
    • Double check you have cublas64_92.dll, cudart64_92.dll, and cudnn64_7.dll in the same directory as lc0.exe
  • CUDA driver version is insufficient for CUDA runtime version
    • You need 397.44 or newer. Download latest from nvidia's website.
  • error Network weights file not found
    • Download the latest weights from http://lczero.org/networks and place in the same directory as lc0.exe.
    • OR: point to the weights using --weights=c:\path\to\weights_476.txt.gz
  • If there are other problems, please upload log.txt to the discord chat #help channel.

Support

Join the discord for quick help, it is usually very active.