X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmaterial.cpp;h=d67b95cae96413746d77176e1dcf9bcb31c73b98;hp=bf0d060fde3f189bfb74a90d5ad63d6fec9fd4cc;hb=e551afbab7767ddf79d33c24f8307a8cb291e3cd;hpb=328d314f2faa128f6bed32e334190cdaed62d9bc diff --git a/src/material.cpp b/src/material.cpp index bf0d060f..d67b95ca 100644 --- a/src/material.cpp +++ b/src/material.cpp @@ -2,6 +2,7 @@ Stockfish, a UCI chess playing engine derived from Glaurung 2.1 Copyright (C) 2004-2008 Tord Romstad (Glaurung author) Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad + Copyright (C) 2015-2017 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad Stockfish is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -30,14 +31,11 @@ namespace { // Polynomial material imbalance parameters - // pair pawn knight bishop rook queen - const int Linear[6] = { 1667, -168, -1027, -166, 238, -138 }; - const int QuadraticOurs[][PIECE_TYPE_NB] = { // OUR PIECES // pair pawn knight bishop rook queen - { 0 }, // Bishop pair - { 40, 2 }, // Pawn + {1667 }, // Bishop pair + { 40, 0 }, // Pawn { 32, 255, -3 }, // Knight OUR PIECES { 0, 104, 4, 0 }, // Bishop { -26, -2, 47, 105, -149 }, // Rook @@ -55,6 +53,17 @@ namespace { { 101, 100, -37, 141, 268, 0 } // Queen }; + // PawnSet[pawn count] contains a bonus/malus indexed by number of pawns + const int PawnSet[] = { + 24, -32, 107, -51, 117, -9, -126, -21, 31 + }; + + // QueenMinorsImbalance[opp_minor_count] is applied when only one side has a queen. + // It contains a bonus/malus for the side with the queen. + const int QueenMinorsImbalance[13] = { + 31, -8, -15, -25, -5 + }; + // Endgame evaluation and scaling functions are accessed directly and not through // the function maps because they correspond to more than one material hash key. Endgame EvaluateKXK[] = { Endgame(WHITE), Endgame(BLACK) }; @@ -91,7 +100,7 @@ namespace { const Color Them = (Us == WHITE ? BLACK : WHITE); - int bonus = 0; + int bonus = PawnSet[pieceCount[Us][PAWN]]; // Second-degree polynomial material imbalance by Tord Romstad for (int pt1 = NO_PIECE_TYPE; pt1 <= QUEEN; ++pt1) @@ -99,7 +108,7 @@ namespace { if (!pieceCount[Us][pt1]) continue; - int v = Linear[pt1]; + int v = 0; for (int pt2 = NO_PIECE_TYPE; pt2 <= pt1; ++pt2) v += QuadraticOurs[pt1][pt2] * pieceCount[Us][pt2] @@ -108,6 +117,10 @@ namespace { bonus += pieceCount[Us][pt1] * v; } + // Special handling of Queen vs. Minors + if (pieceCount[Us][QUEEN] == 1 && pieceCount[Them][QUEEN] == 0) + bonus += QueenMinorsImbalance[pieceCount[Them][KNIGHT] + pieceCount[Them][BISHOP]]; + return bonus; } @@ -131,7 +144,13 @@ Entry* probe(const Position& pos) { std::memset(e, 0, sizeof(Entry)); e->key = key; e->factor[WHITE] = e->factor[BLACK] = (uint8_t)SCALE_FACTOR_NORMAL; - e->gamePhase = pos.game_phase(); + + Value npm_w = pos.non_pawn_material(WHITE); + Value npm_b = pos.non_pawn_material(BLACK); + Value npm = std::max(EndgameLimit, std::min(npm_w + npm_b, MidgameLimit)); + + // Map total non-pawn material into [PHASE_ENDGAME, PHASE_MIDGAME] + e->gamePhase = Phase(((npm - EndgameLimit) * PHASE_MIDGAME) / (MidgameLimit - EndgameLimit)); // Let's look if we have a specialized evaluation function for this particular // material configuration. Firstly we look for a fixed configuration one, then @@ -152,7 +171,7 @@ Entry* probe(const Position& pos) { if ((sf = pos.this_thread()->endgames.probe(key)) != nullptr) { - e->scalingFunction[sf->strong_side()] = sf; // Only strong color assigned + e->scalingFunction[sf->strongSide] = sf; // Only strong color assigned return e; } @@ -168,9 +187,6 @@ Entry* probe(const Position& pos) { e->scalingFunction[c] = &ScaleKQKRPs[c]; } - Value npm_w = pos.non_pawn_material(WHITE); - Value npm_b = pos.non_pawn_material(BLACK); - if (npm_w + npm_b == VALUE_ZERO && pos.pieces(PAWN)) // Only pawns on the board { if (!pos.count(BLACK))