X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmaterial.cpp;h=d67b95cae96413746d77176e1dcf9bcb31c73b98;hp=e22942128f4a98974f856ecefb836c15b091ff8a;hb=e551afbab7767ddf79d33c24f8307a8cb291e3cd;hpb=f7d8ea3866c26df10617e97513e906d1f5a5b833 diff --git a/src/material.cpp b/src/material.cpp index e2294212..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 @@ -30,29 +31,37 @@ namespace { // Polynomial material imbalance parameters - // pair pawn knight bishop rook queen - const int Linear[6] = { 1852, -162, -1122, -183, 249, -154 }; - const int QuadraticOurs[][PIECE_TYPE_NB] = { // OUR PIECES // pair pawn knight bishop rook queen - { 0 }, // Bishop pair - { 39, 2 }, // Pawn - { 35, 271, -4 }, // Knight OUR PIECES - { 0, 105, 4, 0 }, // Bishop - { -27, -2, 46, 100, -141 }, // Rook - {-177, 25, 129, 142, -137, 0 } // Queen + {1667 }, // Bishop pair + { 40, 0 }, // Pawn + { 32, 255, -3 }, // Knight OUR PIECES + { 0, 104, 4, 0 }, // Bishop + { -26, -2, 47, 105, -149 }, // Rook + {-185, 24, 122, 137, -134, 0 } // Queen }; const int QuadraticTheirs[][PIECE_TYPE_NB] = { // THEIR PIECES // pair pawn knight bishop rook queen { 0 }, // Bishop pair - { 37, 0 }, // Pawn - { 10, 62, 0 }, // Knight OUR PIECES - { 57, 64, 39, 0 }, // Bishop - { 50, 40, 23, -22, 0 }, // Rook - { 98, 105, -39, 141, 274, 0 } // Queen + { 36, 0 }, // Pawn + { 9, 63, 0 }, // Knight OUR PIECES + { 59, 65, 42, 0 }, // Bishop + { 46, 39, 24, -24, 0 }, // Rook + { 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 @@ -64,37 +73,34 @@ namespace { Endgame ScaleKPsK[] = { Endgame(WHITE), Endgame(BLACK) }; Endgame ScaleKPKP[] = { Endgame(WHITE), Endgame(BLACK) }; - // Helper templates used to detect a given material distribution - template bool is_KXK(const Position& pos) { - const Color Them = (Us == WHITE ? BLACK : WHITE); - return !more_than_one(pos.pieces(Them)) - && pos.non_pawn_material(Us) >= RookValueMg; + // Helper used to detect a given material distribution + bool is_KXK(const Position& pos, Color us) { + return !more_than_one(pos.pieces(~us)) + && pos.non_pawn_material(us) >= RookValueMg; } - template bool is_KBPsKs(const Position& pos) { - return pos.non_pawn_material(Us) == BishopValueMg - && pos.count(Us) == 1 - && pos.count(Us) >= 1; + bool is_KBPsKs(const Position& pos, Color us) { + return pos.non_pawn_material(us) == BishopValueMg + && pos.count(us) == 1 + && pos.count(us) >= 1; } - template bool is_KQKRPs(const Position& pos) { - const Color Them = (Us == WHITE ? BLACK : WHITE); - return !pos.count(Us) - && pos.non_pawn_material(Us) == QueenValueMg - && pos.count(Us) == 1 - && pos.count(Them) == 1 - && pos.count(Them) >= 1; + bool is_KQKRPs(const Position& pos, Color us) { + return !pos.count(us) + && pos.non_pawn_material(us) == QueenValueMg + && pos.count(us) == 1 + && pos.count(~us) == 1 + && pos.count(~us) >= 1; } /// imbalance() calculates the imbalance by comparing the piece count of each /// piece type for both colors. - template int imbalance(const int pieceCount[][PIECE_TYPE_NB]) { 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) @@ -102,7 +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] @@ -111,6 +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; } @@ -134,7 +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 @@ -142,17 +158,12 @@ Entry* probe(const Position& pos) { if ((e->evaluationFunction = pos.this_thread()->endgames.probe(key)) != nullptr) return e; - if (is_KXK(pos)) - { - e->evaluationFunction = &EvaluateKXK[WHITE]; - return e; - } - - if (is_KXK(pos)) - { - e->evaluationFunction = &EvaluateKXK[BLACK]; - return e; - } + for (Color c = WHITE; c <= BLACK; ++c) + if (is_KXK(pos, c)) + { + e->evaluationFunction = &EvaluateKXK[c]; + return e; + } // OK, we didn't find any special evaluation function for the current material // configuration. Is there a suitable specialized scaling function? @@ -160,27 +171,21 @@ 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; } // We didn't find any specialized scaling function, so fall back on generic // ones that refer to more than one material distribution. Note that in this // case we don't return after setting the function. - if (is_KBPsKs(pos)) - e->scalingFunction[WHITE] = &ScaleKBPsK[WHITE]; - - if (is_KBPsKs(pos)) - e->scalingFunction[BLACK] = &ScaleKBPsK[BLACK]; - - if (is_KQKRPs(pos)) - e->scalingFunction[WHITE] = &ScaleKQKRPs[WHITE]; - - else if (is_KQKRPs(pos)) - e->scalingFunction[BLACK] = &ScaleKQKRPs[BLACK]; + for (Color c = WHITE; c <= BLACK; ++c) + { + if (is_KBPsKs(pos, c)) + e->scalingFunction[c] = &ScaleKBPsK[c]; - Value npm_w = pos.non_pawn_material(WHITE); - Value npm_b = pos.non_pawn_material(BLACK); + else if (is_KQKRPs(pos, c)) + e->scalingFunction[c] = &ScaleKQKRPs[c]; + } if (npm_w + npm_b == VALUE_ZERO && pos.pieces(PAWN)) // Only pawns on the board { @@ -210,11 +215,11 @@ Entry* probe(const Position& pos) { // drawish scale factor for cases such as KRKBP and KmmKm (except for KBBKN). if (!pos.count(WHITE) && npm_w - npm_b <= BishopValueMg) e->factor[WHITE] = uint8_t(npm_w < RookValueMg ? SCALE_FACTOR_DRAW : - npm_b <= BishopValueMg ? 4 : 12); + npm_b <= BishopValueMg ? 4 : 14); if (!pos.count(BLACK) && npm_b - npm_w <= BishopValueMg) e->factor[BLACK] = uint8_t(npm_b < RookValueMg ? SCALE_FACTOR_DRAW : - npm_w <= BishopValueMg ? 4 : 12); + npm_w <= BishopValueMg ? 4 : 14); if (pos.count(WHITE) == 1 && npm_w - npm_b <= BishopValueMg) e->factor[WHITE] = (uint8_t) SCALE_FACTOR_ONEPAWN;