/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
- Copyright (C) 2004-2022 The Stockfish developers (see AUTHORS file)
+ Copyright (C) 2004-2023 The Stockfish developers (see AUTHORS file)
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
// We use the much less accurate but faster Classical eval when the NNUE
// option is set to false. Otherwise we use the NNUE eval unless the
// PSQ advantage is decisive and several pieces remain. (~3 Elo)
- bool useClassical = !useNNUE || (pos.count<ALL_PIECES>() > 7 && abs(psq) > 1760);
+ bool useClassical = !useNNUE || (pos.count<ALL_PIECES>() > 7 && abs(psq) > 1781);
if (useClassical)
v = Evaluation<NO_TRACE>(pos).value();
Value nnue = NNUE::evaluate(pos, true, &nnueComplexity);
// Blend nnue complexity with (semi)classical complexity
- nnueComplexity = ( 412 * nnueComplexity
- + 428 * abs(psq - nnue)
+ nnueComplexity = ( 406 * nnueComplexity
+ + 424 * abs(psq - nnue)
+ (optimism > 0 ? int(optimism) * int(psq - nnue) : 0)
) / 1024;
if (complexity)
*complexity = nnueComplexity;
- optimism = optimism * (278 + nnueComplexity) / 256;
- v = (nnue * scale + optimism * (scale - 755)) / 1024;
+ optimism = optimism * (272 + nnueComplexity) / 256;
+ v = (nnue * scale + optimism * (scale - 748)) / 1024;
}
// Damp down the evaluation linearly when shuffling
- v = v * (197 - pos.rule50_count()) / 214;
+ v = v * (200 - pos.rule50_count()) / 214;
// Guarantee evaluation does not hit the tablebase range
v = std::clamp(v, VALUE_TB_LOSS_IN_MAX_PLY + 1, VALUE_TB_WIN_IN_MAX_PLY - 1);