A try to implement Alexander Shashin's theory on a Stockfish's derived chess engine
ShashChess 25.2 Change log: -Modified Makefile for Android build when curl library gives problems. (USE_LIVEBOOK flag) - Fixed the GoldDigger speed problem by reading the GoldDigger option only once at the beginning of search - Fixed debug assertion in MonteCarlo::print_children() by using root instead of current_node() which is supposed to be equal to root - Fixed MCTS TT updating. - As code cleanup, removed the bool mcts parameter to search() and qsearch() and replaced it with a Thread flag, so that each threads knows if it is running MCTS or not Thanks to Khalid Omar
ShashChess 25.1 Fixed mcts by Shashin Stockfish patch Fix tablebase probe for dtz >1000 w/o 50 move rule For qn4N1/6R1/3K4/8/B2k4/8/8/8 w - - 0 1, white loses with DTZ 1034. See https://syzygy-tables.info/?fen=qn4N1/6R1/3K4/8/B2k4/8/8/8_w_-_-_0_1
Prior to this fix, due to a too small hard-coded value, Stockfish interpreted this as winning. The new value picked (1<<18) is large enough to deal with the largest DTZ values that can be stored in the current syzygy format.
closes #4187
No functional change.
ShashChess 25 Corrected and improved shashin theory New MCTS based on Shashin theory Improved mcts code (a great thanks to Khalid Omar for his help) Stockfish patch: Tweak history initialization Simplify initialization of continuation history by using everywhere the same starting value.
ShashChess 24 Improved Shashin theory Aligned with stockfish patch Make key_after() more consistent with key() Aug 17, 2022
Bug Fix Shashin's Theory
Refined Shashin theory, only at the engine bootstrap. See the Readme file. Non functional change in match play.
ShashChess 23 Cleaned code Aigned with Stockfish patch Jul 13 2022 Update default net to nn-ad9b42354671.nnue using trainer branch glinscott/nnue-pytorch#208 with a slightly tweaked loss function (power 2.5 instead of 2.6), otherwise same training as in the previous net update #4100
ShashChess 22 Improved Shashin theory Aligned with stockfish patch Negative extension for ttMove that is less than alpha and value in the context of singular extensions
Fix bin books management
ShashChess 21
Improved Shashin theory and alignment score-gui. Fixed Montecarlo. Introduced the option Syzygy50MoveRule, as in Stockfish, useful, effectively, for example, in correspondence chess. Introduced the GoldDigger option: if activated, the engine favors depth over the pruning of various selectivity techniques. In this way, it can uncover normally hidden possibilities. In this mode, it solves many more hard positions, although it loses slightly in absolute game strength. Stockfish patch Generalize the feature transform to use vec_t macros This commit generalizes the feature transform to use vec_t macros that are architecture defined instead of using a seperate code path for each one.
It should make some old architectures (MMX, including improvements by Fanael) faster and make further such improvements easier in the future.