tomitankChess is Hungarian (pure) JavaScript Chess Engine

• tomitankChess 2.0 was the first full BitBoard JavaScript chess engine on the World!
• Why pure? Because it is No Emscripten (unlike stockfish-js), so the code is readable.
• Pure JavaScript ~5X slower than "C" language, and ~2.5 slower than Emscripten JavaScript.
• The Engine is running in your browser and with UCI GUI (eg: Arena) as well.

Usage:

• tomitankChess (with node.js) run in Arena, in WinBoard and in Cutechess as well.

• Example for Arena GUI with node.js

  • Command line: direct acces to node.exe (C:\Program Files\nodejs\node.exe)
  • Command line parameters: direct acces to tomitankChess.js (C:\Program Files\nodejs\tomitankChessUCI.js)

• Web browser: tomitankChess runing with and without WebWorker as well. (Recommended: WebWorker)

  • Input (standard UCI commands) to the engine is posted as a message to the worker. Example:

  • var tomitankChess = new Worker('tomitankChess.js');

  • tomitankChess.postMessage('ucinewgame');

  • tomitankChess.postMessage('isready');

  • at this point you need to wait (eg with Promise) for readyok response

  • tomitankChess.postMessage('go depth 12');

  • JSUCI: https://sourceforge.net/projects/jsuci/

Estimated level (CCRL 40/40):

• 5.1: ~2920 elo (Strongest JavaScript Chess Engine /2021.08.08/)
• 5.0: ~2900 elo (Strongest JavaScript Chess Engine /2021.01.18/)
• 4.2: ~2830 elo (Strongest JavaScript Chess Engine /2020.09.24/)
• 4.0: ~2820 elo (Strongest JavaScript Chess Engine /2020.01.24/)
• 3.0: ~2780 elo (Strongest JavaScript Chess Engine /2019.01.14/)
• 2.1: ~2660 elo (Strongest JavaScript Chess Engine /2018.11.26/)
• 2.0: ~2660 elo (Strongest JavaScript Chess Engine /2018.07.11/)
• 1.5: ~2590 elo (Strongest JavaScript Chess Engine /2017.12.03/)
• 1.4: ~2550 elo (Strongest JavaScript Chess Engine /2017.09.30/)
• Click here to see all CCRL 40/40 results of tomitankChess

Links:

• Web: http://tanky.hu or http://mobil.tanky.hu
• Android app: https://play.google.com/store/apps/details?id=sakk.tanky.hu
• iOS app: https://itunes.apple.com/us/app/sakk-ingyenes/id1150654415?l=hu&ls=1&mt=8

Have fun with tomitankChess!

-Tamás Kuzmics

Changes log:

• v5.1

  • network is trained with 4M example instead of 2.7M as in the previous version. (same size 768x16x1)
  • better hash table usage (prune more in Qsearch as well, and improve hash store)
  • around 20 elo better than previous version

• v5.0

  • Added eval (NN)! Network size is only 768x16x1. Smaller than I've seen before.
  • it does not replace evaluation, it only compensates that.
  • trained only with 2.7M example.
  • The network is not compatible with other engines and it's integrated into the code. (hardcoded)
  • I wrote the network from scratch. I don't use machine learning platform.
  • I have around 10 elo better net (768x32x1) in fix depth test, but JavaScript is too slow, and don’t have AVX or similar methode in JavaScript (so i use vanilla approach). Essentially the smaller net has nearly the same strength in both short and long TC tests.

• v4.2

  • revisited code
  • rewrite pawn eval
  • fixed a bug that's caused problem in IE

• v4.0

  • see pruning
  • better lmr
  • rewrited pawn eval
  • new pawn shield code
  • new see (add discovered checks)
  • lots of little things (revisited code)

• v3.0

  • new pawn shield code (idea from Senpai 2, but a bit better)
  • use 3x3 squares king ring (idea from Senpai 2)
  • new king safety code (simple, but bit better)
  • all parameters scoring by logistic regression
  • better time management (take more time when unsure)
  • 4-way transposition table
  • lots of little things (revisited code)

• v2.1

  • Revisited code (threats, move gen, some bug-fix, etc..)
  • Store eval score in hash
  • Smaller king-ring
  • Added logo.png

• v2.0

  • first full BitBoard JavaScript chess engine on the World
  • added check evasions code
  • added threats for all pieces
  • added new passed pawn eval
  • new King Safety (bigger and pawn-safe king ring)
  • new non-linear and pawn-safe mobility (Same in mg and eg)
  • better aspiration window
  • a bit better delta pruning
  • Don't give back the "upper bounds" moves
  • pre-calculate and transmit the "gives check"
  • added pawn hash (there is no elo gain yet, but it will be useful for a more complex pawn evaluation.)
  • Typed Arrays Hash table for better memory usage
  • added "Hash option" (default 32 min 1 max 256)
  • added "eval" command (show the static evaluation)
  • lots of little things

• v1.5

  • New UI interface code (now working with JSUCI as well)
  • Tuned Search algorithm
  • Use TT at depth == 0

• v1.4

  • first public version