X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fevaluate.cpp;h=47d5eb3e9bc93760432f369c04195afff4f20ac3;hp=e83f792848d2aa4c8e2941fa6862709123b2005d;hb=94b9c65e09b5d396bebb29b62d9979139b5fbdfa;hpb=237dd331d5c346af5bf305f27d259278405c7034 diff --git a/src/evaluate.cpp b/src/evaluate.cpp index e83f7928..47d5eb3e 100644 --- a/src/evaluate.cpp +++ b/src/evaluate.cpp @@ -1,7 +1,7 @@ /* Stockfish, a UCI chess playing engine derived from Glaurung 2.1 Copyright (C) 2004-2008 Tord Romstad (Glaurung author) - Copyright (C) 2008-2009 Marco Costalba + Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, 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 @@ -29,7 +29,6 @@ #include "evaluate.h" #include "material.h" #include "pawns.h" -#include "scale.h" #include "thread.h" #include "ucioption.h" @@ -46,11 +45,11 @@ namespace { const int GrainSize = 8; // Evaluation weights, initialized from UCI options - int WeightMobilityMidgame, WeightMobilityEndgame; - int WeightPawnStructureMidgame, WeightPawnStructureEndgame; - int WeightPassedPawnsMidgame, WeightPassedPawnsEndgame; - int WeightKingSafety[2]; - int WeightSpace; + enum { Mobility, PawnStructure, PassedPawns, Space, KingDangerUs, KingDangerThem }; + Score Weights[6]; + + typedef Value V; + #define S(mg, eg) make_score(mg, eg) // Internal evaluation weights. These are applied on top of the evaluation // weights read from UCI parameters. The purpose is to be able to change @@ -58,90 +57,51 @@ namespace { // parameters at 100, which looks prettier. // // Values modified by Joona Kiiski - const int WeightMobilityMidgameInternal = 248; - const int WeightMobilityEndgameInternal = 271; - const int WeightPawnStructureMidgameInternal = 233; - const int WeightPawnStructureEndgameInternal = 201; - const int WeightPassedPawnsMidgameInternal = 252; - const int WeightPassedPawnsEndgameInternal = 259; - const int WeightKingSafetyInternal = 247; - const int WeightKingOppSafetyInternal = 259; - const int WeightSpaceInternal = 46; - - // Mobility and outposts bonus modified by Joona Kiiski - // - // Visually better to define tables constants - typedef Value V; + const Score WeightsInternal[] = { + S(248, 271), S(233, 201), S(252, 259), S(46, 0), S(247, 0), S(259, 0) + }; // Knight mobility bonus in middle game and endgame, indexed by the number // of attacked squares not occupied by friendly piecess. - const Value MidgameKnightMobilityBonus[] = { - // 0 1 2 3 4 5 6 7 8 - V(-38), V(-25),V(-12), V(0), V(12), V(25), V(31), V(38), V(38) - }; - - const Value EndgameKnightMobilityBonus[] = { - // 0 1 2 3 4 5 6 7 8 - V(-33), V(-23),V(-13), V(-3), V(7), V(17), V(22), V(27), V(27) + const Score KnightMobilityBonus[16] = { + S(-38,-33), S(-25,-23), S(-12,-13), S( 0,-3), + S( 12, 7), S( 25, 17), S( 31, 22), S(38, 27), S(38, 27) }; // Bishop mobility bonus in middle game and endgame, indexed by the number // of attacked squares not occupied by friendly pieces. X-ray attacks through // queens are also included. - const Value MidgameBishopMobilityBonus[] = { - // 0 1 2 3 4 5 6 7 - V(-25), V(-11), V(3), V(17), V(31), V(45), V(57), V(65), - // 8 9 10 11 12 13 14 15 - V( 71), V( 74), V(76), V(78), V(79), V(80), V(81), V(81) - }; - - const Value EndgameBishopMobilityBonus[] = { - // 0 1 2 3 4 5 6 7 - V(-30), V(-16), V(-2), V(12), V(26), V(40), V(52), V(60), - // 8 9 10 11 12 13 14 15 - V( 65), V( 69), V(71), V(73), V(74), V(75), V(76), V(76) + const Score BishopMobilityBonus[16] = { + S(-25,-30), S(-11,-16), S( 3, -2), S(17, 12), + S( 31, 26), S( 45, 40), S(57, 52), S(65, 60), + S( 71, 65), S( 74, 69), S(76, 71), S(78, 73), + S( 79, 74), S( 80, 75), S(81, 76), S(81, 76) }; // Rook mobility bonus in middle game and endgame, indexed by the number // of attacked squares not occupied by friendly pieces. X-ray attacks through // queens and rooks are also included. - const Value MidgameRookMobilityBonus[] = { - // 0 1 2 3 4 5 6 7 - V(-20), V(-14), V(-8), V(-2), V(4), V(10), V(14), V(19), - // 8 9 10 11 12 13 14 15 - V( 23), V( 26), V(27), V(28), V(29), V(30), V(31), V(32) - }; - - const Value EndgameRookMobilityBonus[] = { - // 0 1 2 3 4 5 6 7 - V(-36), V(-19), V(-3), V(13), V(29), V(46), V(62), V(79), - // 8 9 10 11 12 13 14 15 - V( 95), V(106),V(111),V(114),V(116),V(117),V(118),V(118) + const Score RookMobilityBonus[16] = { + S(-20,-36), S(-14,-19), S(-8, -3), S(-2, 13), + S( 4, 29), S( 10, 46), S(14, 62), S(19, 79), + S( 23, 95), S( 26,106), S(27,111), S(28,114), + S( 29,116), S( 30,117), S(31,118), S(32,118) }; // Queen mobility bonus in middle game and endgame, indexed by the number // of attacked squares not occupied by friendly pieces. - const Value MidgameQueenMobilityBonus[] = { - // 0 1 2 3 4 5 6 7 - V(-10), V(-8), V(-6), V(-3), V(-1), V( 1), V( 3), V( 5), - // 8 9 10 11 12 13 14 15 - V( 8), V(10), V(12), V(15), V(16), V(17), V(18), V(20), - // 16 17 18 19 20 21 22 23 - V( 20), V(20), V(20), V(20), V(20), V(20), V(20), V(20), - // 24 25 26 27 28 29 30 31 - V( 20), V(20), V(20), V(20), V(20), V(20), V(20), V(20) + const Score QueenMobilityBonus[32] = { + S(-10,-18), S(-8,-13), S(-6, -7), S(-3, -2), S(-1, 3), S( 1, 8), + S( 3, 13), S( 5, 19), S( 8, 23), S(10, 27), S(12, 32), S(15, 34), + S( 16, 35), S(17, 35), S(18, 35), S(20, 35), S(20, 35), S(20, 35), + S( 20, 35), S(20, 35), S(20, 35), S(20, 35), S(20, 35), S(20, 35), + S( 20, 35), S(20, 35), S(20, 35), S(20, 35), S(20, 35), S(20, 35), + S( 20, 35), S(20, 35) }; - const Value EndgameQueenMobilityBonus[] = { - // 0 1 2 3 4 5 6 7 - V(-18),V(-13), V(-7), V(-2), V( 3), V (8), V(13), V(19), - // 8 9 10 11 12 13 14 15 - V( 23), V(27), V(32), V(34), V(35), V(35), V(35), V(35), - // 16 17 18 19 20 21 22 23 - V( 35), V(35), V(35), V(35), V(35), V(35), V(35), V(35), - // 24 25 26 27 28 29 30 31 - V( 35), V(35), V(35), V(35), V(35), V(35), V(35), V(35) - }; + // Pointers table to access mobility tables through piece type + const Score* MobilityBonus[8] = { 0, 0, KnightMobilityBonus, BishopMobilityBonus, + RookMobilityBonus, QueenMobilityBonus, 0, 0 }; // Outpost bonuses for knights and bishops, indexed by square (from white's // point of view). @@ -169,18 +129,34 @@ namespace { V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0) // 8 }; + // ThreatBonus[attacking][attacked] contains bonus according to which + // piece type attacks which one. + const Score ThreatBonus[8][8] = { + {}, {}, + { S(0, 0), S( 7, 39), S( 0, 0), S(24, 49), S(41,100), S(41,100) }, // KNIGHT + { S(0, 0), S( 7, 39), S(24, 49), S( 0, 0), S(41,100), S(41,100) }, // BISHOP + { S(0, 0), S(-1, 29), S(15, 49), S(15, 49), S( 0, 0), S(24, 49) }, // ROOK + { S(0, 0), S(15, 39), S(15, 39), S(15, 39), S(15, 39), S( 0, 0) } // QUEEN + }; + + // ThreatedByPawnPenalty[] contains a penalty according to which piece + // type is attacked by an enemy pawn. + const Score ThreatedByPawnPenalty[8] = { + S(0, 0), S(0, 0), S(56, 70), S(56, 70), S(76, 99), S(86, 118) + }; + + #undef S + // Bonus for unstoppable passed pawns const Value UnstoppablePawnValue = Value(0x500); // Rooks and queens on the 7th rank (modified by Joona Kiiski) - const Value MidgameRookOn7thBonus = Value(47); - const Value EndgameRookOn7thBonus = Value(98); - const Value MidgameQueenOn7thBonus = Value(27); - const Value EndgameQueenOn7thBonus = Value(54); + const Score RookOn7thBonus = make_score(47, 98); + const Score QueenOn7thBonus = make_score(27, 54); // Rooks on open files (modified by Joona Kiiski) - const Value RookOpenFileBonus = Value(43); - const Value RookHalfOpenFileBonus = Value(19); + const Score RookOpenFileBonus = make_score(43, 43); + const Score RookHalfOpenFileBonus = make_score(19, 19); // Penalty for rooks trapped inside a friendly king which has lost the // right to castle. @@ -188,7 +164,7 @@ namespace { // Penalty for a bishop on a7/h7 (a2/h2 for black) which is trapped by // enemy pawns. - const Value TrappedBishopA7H7Penalty = Value(300); + const Score TrappedBishopA7H7Penalty = make_score(300, 300); // Bitboard masks for detecting trapped bishops on a7/h7 (a2/h2 for black) const Bitboard MaskA7H7[2] = { @@ -199,7 +175,7 @@ namespace { // Penalty for a bishop on a1/h1 (a8/h8 for black) which is trapped by // a friendly pawn on b2/g2 (b7/g7 for black). This can obviously only // happen in Chess960 games. - const Value TrappedBishopA1H1Penalty = Value(100); + const Score TrappedBishopA1H1Penalty = make_score(100, 100); // Bitboard masks for detecting trapped bishops on a1/h1 (a8/h8 for black) const Bitboard MaskA1H1[2] = { @@ -207,7 +183,7 @@ namespace { ((1ULL << SQ_A8) | (1ULL << SQ_H8)) }; - // The SpaceMask[color] contains the area of the board which is consdered + // The SpaceMask[color] contains the area of the board which is considered // by the space evaluation. In the middle game, each side is given a bonus // based on how many squares inside this area are safe and available for // friendly minor pieces. @@ -220,26 +196,20 @@ namespace { (1ULL< - Value do_evaluate(const Position& pos, EvalInfo& ei, int threadID); + Value do_evaluate(const Position& pos, EvalInfo& ei); + + template + void init_attack_tables(const Position& pos, EvalInfo& ei); template void evaluate_pieces_of_color(const Position& pos, EvalInfo& ei); @@ -276,15 +249,21 @@ namespace { template void evaluate_king(const Position& pos, EvalInfo& ei); + template + void evaluate_threats(const Position& pos, EvalInfo& ei); + template - void evaluate_space(const Position& pos, EvalInfo& ei); + int evaluate_space(const Position& pos, EvalInfo& ei); + template void evaluate_passed_pawns(const Position& pos, EvalInfo& ei); + + void evaluate_unstoppable_pawns(const Position& pos, EvalInfo& ei); void evaluate_trapped_bishop_a7h7(const Position& pos, Square s, Color us, EvalInfo& ei); void evaluate_trapped_bishop_a1h1(const Position& pos, Square s, Color us, EvalInfo& ei); - inline Value apply_weight(Value v, int w); - Value scale_by_game_phase(Value mv, Value ev, Phase ph, const ScaleFactor sf[]); - int weight_option(const std::string& opt, int weight); + inline Score apply_weight(Score v, Score weight); + Value scale_by_game_phase(const Score& v, Phase ph, const ScaleFactor sf[]); + Score weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight); void init_safety(); } @@ -296,31 +275,32 @@ namespace { /// evaluate() is the main evaluation function. It always computes two /// values, an endgame score and a middle game score, and interpolates /// between them based on the remaining material. -Value evaluate(const Position& pos, EvalInfo& ei, int threadID) { +Value evaluate(const Position& pos, EvalInfo& ei) { - return CpuHasPOPCNT ? do_evaluate(pos, ei, threadID) - : do_evaluate(pos, ei, threadID); + return CpuHasPOPCNT ? do_evaluate(pos, ei) + : do_evaluate(pos, ei); } namespace { template -Value do_evaluate(const Position& pos, EvalInfo& ei, int threadID) { +Value do_evaluate(const Position& pos, EvalInfo& ei) { + + ScaleFactor factor[2]; assert(pos.is_ok()); - assert(threadID >= 0 && threadID < THREAD_MAX); + assert(pos.thread() >= 0 && pos.thread() < MAX_THREADS); + assert(!pos.is_check()); memset(&ei, 0, sizeof(EvalInfo)); // Initialize by reading the incrementally updated scores included in the // position object (material + piece square tables) - ei.mgValue = pos.mg_value(); - ei.egValue = pos.eg_value(); + ei.value = pos.value(); // Probe the material hash table - ei.mi = MaterialTable[threadID]->get_material_info(pos); - ei.mgValue += ei.mi->material_value(); - ei.egValue += ei.mi->material_value(); + ei.mi = MaterialTable[pos.thread()]->get_material_info(pos); + ei.value += ei.mi->material_value(); // If we have a specialized evaluation function for the current material // configuration, call it and return @@ -328,31 +308,16 @@ Value do_evaluate(const Position& pos, EvalInfo& ei, int threadID) { return ei.mi->evaluate(pos); // After get_material_info() call that modifies them - ScaleFactor factor[2]; factor[WHITE] = ei.mi->scale_factor(pos, WHITE); factor[BLACK] = ei.mi->scale_factor(pos, BLACK); // Probe the pawn hash table - ei.pi = PawnTable[threadID]->get_pawn_info(pos); - ei.mgValue += apply_weight(ei.pi->mg_value(), WeightPawnStructureMidgame); - ei.egValue += apply_weight(ei.pi->eg_value(), WeightPawnStructureEndgame); - - // Initialize king attack bitboards and king attack zones for both sides - ei.attackedBy[WHITE][KING] = pos.attacks_from(pos.king_square(WHITE)); - ei.attackedBy[BLACK][KING] = pos.attacks_from(pos.king_square(BLACK)); - ei.kingZone[WHITE] = ei.attackedBy[BLACK][KING] | (ei.attackedBy[BLACK][KING] >> 8); - ei.kingZone[BLACK] = ei.attackedBy[WHITE][KING] | (ei.attackedBy[WHITE][KING] << 8); - - // Initialize pawn attack bitboards for both sides - ei.attackedBy[WHITE][PAWN] = ((pos.pieces(PAWN, WHITE) << 9) & ~FileABB) | ((pos.pieces(PAWN, WHITE) << 7) & ~FileHBB); - ei.attackedBy[BLACK][PAWN] = ((pos.pieces(PAWN, BLACK) >> 7) & ~FileABB) | ((pos.pieces(PAWN, BLACK) >> 9) & ~FileHBB); - Bitboard b1 = ei.attackedBy[WHITE][PAWN] & ei.attackedBy[BLACK][KING]; - Bitboard b2 = ei.attackedBy[BLACK][PAWN] & ei.attackedBy[WHITE][KING]; - if (b1) - ei.kingAttackersCount[WHITE] = count_1s_max_15(b1)/2; - - if (b2) - ei.kingAttackersCount[BLACK] = count_1s_max_15(b2)/2; + ei.pi = PawnTable[pos.thread()]->get_pawn_info(pos); + ei.value += apply_weight(ei.pi->pawns_value(), Weights[PawnStructure]); + + // Initialize attack bitboards with pawns evaluation + init_attack_tables(pos, ei); + init_attack_tables(pos, ei); // Evaluate pieces evaluate_pieces_of_color(pos, ei); @@ -364,48 +329,51 @@ Value do_evaluate(const Position& pos, EvalInfo& ei, int threadID) { evaluate_king(pos, ei); evaluate_king(pos, ei); - // Evaluate passed pawns. We evaluate passed pawns for both sides at once, - // because we need to know which side promotes first in positions where - // both sides have an unstoppable passed pawn. - if (ei.pi->passed_pawns()) - evaluate_passed_pawns(pos, ei); + // Evaluate tactical threats, we need full attack info including king + evaluate_threats(pos, ei); + evaluate_threats(pos, ei); + + // Evaluate passed pawns, we need full attack info including king + evaluate_passed_pawns(pos, ei); + evaluate_passed_pawns(pos, ei); + + // If one side has only a king, check whether exsists any unstoppable passed pawn + if (!pos.non_pawn_material(WHITE) || !pos.non_pawn_material(BLACK)) + evaluate_unstoppable_pawns(pos, ei); - Phase phase = pos.game_phase(); + Phase phase = ei.mi->game_phase(); // Middle-game specific evaluation terms if (phase > PHASE_ENDGAME) { - // Pawn storms in positions with opposite castling. - if ( square_file(pos.king_square(WHITE)) >= FILE_E - && square_file(pos.king_square(BLACK)) <= FILE_D) + // Pawn storms in positions with opposite castling + if ( square_file(pos.king_square(WHITE)) >= FILE_E + && square_file(pos.king_square(BLACK)) <= FILE_D) - ei.mgValue += ei.pi->queenside_storm_value(WHITE) - - ei.pi->kingside_storm_value(BLACK); + ei.value += make_score(ei.pi->queenside_storm_value(WHITE) - ei.pi->kingside_storm_value(BLACK), 0); - else if ( square_file(pos.king_square(WHITE)) <= FILE_D - && square_file(pos.king_square(BLACK)) >= FILE_E) + else if ( square_file(pos.king_square(WHITE)) <= FILE_D + && square_file(pos.king_square(BLACK)) >= FILE_E) - ei.mgValue += ei.pi->kingside_storm_value(WHITE) - - ei.pi->queenside_storm_value(BLACK); + ei.value += make_score(ei.pi->kingside_storm_value(WHITE) - ei.pi->queenside_storm_value(BLACK), 0); - // Evaluate space for both sides - if (ei.mi->space_weight() > 0) - { - evaluate_space(pos, ei); - evaluate_space(pos, ei); - } + // Evaluate space for both sides + if (ei.mi->space_weight() > 0) + { + int s = evaluate_space(pos, ei) - evaluate_space(pos, ei); + ei.value += apply_weight(make_score(s * ei.mi->space_weight(), 0), Weights[Space]); + } } // Mobility - ei.mgValue += apply_weight(ei.mgMobility, WeightMobilityMidgame); - ei.egValue += apply_weight(ei.egMobility, WeightMobilityEndgame); + ei.value += apply_weight(ei.mobility, Weights[Mobility]); // If we don't already have an unusual scale factor, check for opposite // colored bishop endgames, and use a lower scale for those if ( phase < PHASE_MIDGAME && pos.opposite_colored_bishops() - && ( (factor[WHITE] == SCALE_FACTOR_NORMAL && ei.egValue > Value(0)) - || (factor[BLACK] == SCALE_FACTOR_NORMAL && ei.egValue < Value(0)))) + && ( (factor[WHITE] == SCALE_FACTOR_NORMAL && eg_value(ei.value) > VALUE_ZERO) + || (factor[BLACK] == SCALE_FACTOR_NORMAL && eg_value(ei.value) < VALUE_ZERO))) { ScaleFactor sf; @@ -430,42 +398,18 @@ Value do_evaluate(const Position& pos, EvalInfo& ei, int threadID) { } // Interpolate between the middle game and the endgame score - Color stm = pos.side_to_move(); - - Value v = Sign[stm] * scale_by_game_phase(ei.mgValue, ei.egValue, phase, factor); - - return (ei.mateThreat[stm] == MOVE_NONE ? v : 8 * QueenValueMidgame - v); + return Sign[pos.side_to_move()] * scale_by_game_phase(ei.value, phase, factor); } } // namespace -/// quick_evaluate() does a very approximate evaluation of the current position. -/// It currently considers only material and piece square table scores. Perhaps -/// we should add scores from the pawn and material hash tables? - -Value quick_evaluate(const Position &pos) { - - assert(pos.is_ok()); - - static const - ScaleFactor sf[2] = {SCALE_FACTOR_NORMAL, SCALE_FACTOR_NORMAL}; - - Value mgv = pos.mg_value(); - Value egv = pos.eg_value(); - Phase ph = pos.game_phase(); - Color stm = pos.side_to_move(); - - return Sign[stm] * scale_by_game_phase(mgv, egv, ph, sf); -} - - /// init_eval() initializes various tables used by the evaluation function void init_eval(int threads) { - assert(threads <= THREAD_MAX); + assert(threads <= MAX_THREADS); - for (int i = 0; i < THREAD_MAX; i++) + for (int i = 0; i < MAX_THREADS; i++) { if (i >= threads) { @@ -487,7 +431,7 @@ void init_eval(int threads) { void quit_eval() { - for (int i = 0; i < THREAD_MAX; i++) + for (int i = 0; i < MAX_THREADS; i++) { delete PawnTable[i]; delete MaterialTable[i]; @@ -501,63 +445,43 @@ void quit_eval() { void read_weights(Color us) { - Color them = opposite_color(us); + // King safety is asymmetrical. Our king danger level is weighted by + // "Cowardice" UCI parameter, instead the opponent one by "Aggressiveness". + const int kingDangerUs = (us == WHITE ? KingDangerUs : KingDangerThem); + const int kingDangerThem = (us == WHITE ? KingDangerThem : KingDangerUs); - WeightMobilityMidgame = weight_option("Mobility (Middle Game)", WeightMobilityMidgameInternal); - WeightMobilityEndgame = weight_option("Mobility (Endgame)", WeightMobilityEndgameInternal); - WeightPawnStructureMidgame = weight_option("Pawn Structure (Middle Game)", WeightPawnStructureMidgameInternal); - WeightPawnStructureEndgame = weight_option("Pawn Structure (Endgame)", WeightPawnStructureEndgameInternal); - WeightPassedPawnsMidgame = weight_option("Passed Pawns (Middle Game)", WeightPassedPawnsMidgameInternal); - WeightPassedPawnsEndgame = weight_option("Passed Pawns (Endgame)", WeightPassedPawnsEndgameInternal); - WeightSpace = weight_option("Space", WeightSpaceInternal); - WeightKingSafety[us] = weight_option("Cowardice", WeightKingSafetyInternal); - WeightKingSafety[them] = weight_option("Aggressiveness", WeightKingOppSafetyInternal); + Weights[Mobility] = weight_option("Mobility (Middle Game)", "Mobility (Endgame)", WeightsInternal[Mobility]); + Weights[PawnStructure] = weight_option("Pawn Structure (Middle Game)", "Pawn Structure (Endgame)", WeightsInternal[PawnStructure]); + Weights[PassedPawns] = weight_option("Passed Pawns (Middle Game)", "Passed Pawns (Endgame)", WeightsInternal[PassedPawns]); + Weights[Space] = weight_option("Space", "Space", WeightsInternal[Space]); + Weights[kingDangerUs] = weight_option("Cowardice", "Cowardice", WeightsInternal[KingDangerUs]); + Weights[kingDangerThem] = weight_option("Aggressiveness", "Aggressiveness", WeightsInternal[KingDangerThem]); // If running in analysis mode, make sure we use symmetrical king safety. We do this - // by replacing both WeightKingSafety[us] and WeightKingSafety[them] by their average. + // by replacing both Weights[kingDangerUs] and Weights[kingDangerThem] by their average. if (get_option_value_bool("UCI_AnalyseMode")) - { - WeightKingSafety[us] = (WeightKingSafety[us] + WeightKingSafety[them]) / 2; - WeightKingSafety[them] = WeightKingSafety[us]; - } + Weights[kingDangerUs] = Weights[kingDangerThem] = (Weights[kingDangerUs] + Weights[kingDangerThem]) / 2; + init_safety(); } namespace { - // evaluate_mobility() computes mobility and attacks for every piece + // init_attack_tables() initializes king bitboards for both sides adding + // pawn attacks. To be done before other evaluations. - template - int evaluate_mobility(const Position& pos, const Bitboard& mob_bb, EvalInfo& ei) { + template + void init_attack_tables(const Position& pos, EvalInfo& ei) { const Color Them = (Us == WHITE ? BLACK : WHITE); - static const int AttackWeight[] = { 0, 0, KnightAttackWeight, BishopAttackWeight, RookAttackWeight, QueenAttackWeight }; - static const Value* MgBonus[] = { 0, 0, MidgameKnightMobilityBonus, MidgameBishopMobilityBonus, MidgameRookMobilityBonus, MidgameQueenMobilityBonus }; - static const Value* EgBonus[] = { 0, 0, EndgameKnightMobilityBonus, EndgameBishopMobilityBonus, EndgameRookMobilityBonus, EndgameQueenMobilityBonus }; - - // Update attack info - ei.attackedBy[Us][Piece] |= mob_bb; - // King attacks - if (mob_bb & ei.kingZone[Us]) - { - ei.kingAttackersCount[Us]++; - ei.kingAttackersWeight[Us] += AttackWeight[Piece]; - Bitboard b = (mob_bb & ei.attackedBy[Them][KING]); - if (b) - ei.kingAdjacentZoneAttacksCount[Us] += count_1s_max_15(b); - } - - // Remove squares protected by enemy pawns or occupied by our pieces - Bitboard b = mob_bb & ~ei.attackedBy[Them][PAWN] & ~pos.pieces_of_color(Us); - - // Mobility - int mob = (Piece != QUEEN ? count_1s_max_15(b) : count_1s(b)); - - ei.mgMobility += Sign[Us] * MgBonus[Piece][mob]; - ei.egMobility += Sign[Us] * EgBonus[Piece][mob]; - return mob; + Bitboard b = ei.attackedBy[Them][KING] = pos.attacks_from(pos.king_square(Them)); + ei.kingZone[Us] = (b | (Us == WHITE ? b >> 8 : b << 8)); + ei.attackedBy[Us][PAWN] = ei.pi->pawn_attacks(Us); + b &= ei.attackedBy[Us][PAWN]; + if (b) + ei.kingAttackersCount[Us] = count_1s_max_15(b) / 2; } @@ -574,7 +498,7 @@ namespace { // Increase bonus if supported by pawn, especially if the opponent has // no minor piece which can exchange the outpost piece - if (bonus && (pos.attacks_from(s, Them) & pos.pieces(PAWN, Us))) + if (bonus && bit_is_set(ei.attackedBy[Us][PAWN], s)) { if ( pos.pieces(KNIGHT, Them) == EmptyBoardBB && (SquaresByColorBB[square_color(s)] & pos.pieces(BISHOP, Them)) == EmptyBoardBB) @@ -582,17 +506,16 @@ namespace { else bonus += bonus / 2; } - ei.mgValue += Sign[Us] * bonus; - ei.egValue += Sign[Us] * bonus; + ei.value += Sign[Us] * make_score(bonus, bonus); } // evaluate_pieces<>() assigns bonuses and penalties to the pieces of a given color template - void evaluate_pieces(const Position& pos, EvalInfo& ei) { + void evaluate_pieces(const Position& pos, EvalInfo& ei, Bitboard no_mob_area) { - Bitboard mob_bb; + Bitboard b; Square s, ksq; int mob; File f; @@ -602,20 +525,42 @@ namespace { while ((s = *ptr++) != SQ_NONE) { + // Find attacked squares, including x-ray attacks for bishops and rooks if (Piece == KNIGHT || Piece == QUEEN) - mob_bb = pos.attacks_from(s); + b = pos.attacks_from(s); else if (Piece == BISHOP) - mob_bb = bishop_attacks_bb(s, pos.occupied_squares() & ~pos.pieces(QUEEN, Us)); + b = bishop_attacks_bb(s, pos.occupied_squares() & ~pos.pieces(QUEEN, Us)); else if (Piece == ROOK) - mob_bb = rook_attacks_bb(s, pos.occupied_squares() & ~pos.pieces(ROOK, QUEEN, Us)); + b = rook_attacks_bb(s, pos.occupied_squares() & ~pos.pieces(ROOK, QUEEN, Us)); else assert(false); - // Attacks and mobility - mob = evaluate_mobility(pos, mob_bb, ei); + // Update attack info + ei.attackedBy[Us][Piece] |= b; + + // King attacks + if (b & ei.kingZone[Us]) + { + ei.kingAttackersCount[Us]++; + ei.kingAttackersWeight[Us] += KingAttackWeights[Piece]; + Bitboard bb = (b & ei.attackedBy[Them][KING]); + if (bb) + ei.kingAdjacentZoneAttacksCount[Us] += count_1s_max_15(bb); + } + + // Mobility + mob = (Piece != QUEEN ? count_1s_max_15(b & no_mob_area) + : count_1s(b & no_mob_area)); + + ei.mobility += Sign[Us] * MobilityBonus[Piece][mob]; + + // Decrease score if we are attacked by an enemy pawn. Remaining part + // of threat evaluation must be done later when we have full attack info. + if (bit_is_set(ei.attackedBy[Them][PAWN], s)) + ei.value -= Sign[Us] * ThreatedByPawnPenalty[Piece]; // Bishop and knight outposts squares - if ((Piece == BISHOP || Piece == KNIGHT) && pos.square_is_weak(s, Them)) + if ((Piece == BISHOP || Piece == KNIGHT) && pos.square_is_weak(s, Us)) evaluate_outposts(pos, ei, s); // Special patterns: trapped bishops on a7/h7/a2/h2 @@ -629,15 +574,12 @@ namespace { evaluate_trapped_bishop_a1h1(pos, s, Us, ei); } - if (Piece == ROOK || Piece == QUEEN) + // Queen or rook on 7th rank + if ( (Piece == ROOK || Piece == QUEEN) + && relative_rank(Us, s) == RANK_7 + && relative_rank(Us, pos.king_square(Them)) == RANK_8) { - // Queen or rook on 7th rank - if ( relative_rank(Us, s) == RANK_7 - && relative_rank(Us, pos.king_square(Them)) == RANK_8) - { - ei.mgValue += Sign[Us] * (Piece == ROOK ? MidgameRookOn7thBonus : MidgameQueenOn7thBonus); - ei.egValue += Sign[Us] * (Piece == ROOK ? EndgameRookOn7thBonus : EndgameQueenOn7thBonus); - } + ei.value += Sign[Us] * (Piece == ROOK ? RookOn7thBonus : QueenOn7thBonus); } // Special extra evaluation for rooks @@ -648,15 +590,9 @@ namespace { if (ei.pi->file_is_half_open(Us, f)) { if (ei.pi->file_is_half_open(Them, f)) - { - ei.mgValue += Sign[Us] * RookOpenFileBonus; - ei.egValue += Sign[Us] * RookOpenFileBonus; - } + ei.value += Sign[Us] * RookOpenFileBonus; else - { - ei.mgValue += Sign[Us] * RookHalfOpenFileBonus; - ei.egValue += Sign[Us] * RookHalfOpenFileBonus; - } + ei.value += Sign[Us] * RookHalfOpenFileBonus; } // Penalize rooks which are trapped inside a king. Penalize more if @@ -672,38 +608,76 @@ namespace { { // Is there a half-open file between the king and the edge of the board? if (!ei.pi->has_open_file_to_right(Us, square_file(ksq))) - ei.mgValue -= pos.can_castle(Us)? Sign[Us] * ((TrappedRookPenalty - mob * 16) / 2) - : Sign[Us] * (TrappedRookPenalty - mob * 16); + ei.value -= Sign[Us] * make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2 + : (TrappedRookPenalty - mob * 16), 0); } else if ( square_file(ksq) <= FILE_D - && square_file(s) < square_file(ksq) - && (relative_rank(Us, ksq) == RANK_1 || square_rank(ksq) == square_rank(s))) + && square_file(s) < square_file(ksq) + && (relative_rank(Us, ksq) == RANK_1 || square_rank(ksq) == square_rank(s))) { // Is there a half-open file between the king and the edge of the board? if (!ei.pi->has_open_file_to_left(Us, square_file(ksq))) - ei.mgValue -= pos.can_castle(Us)? Sign[Us] * ((TrappedRookPenalty - mob * 16) / 2) - : Sign[Us] * (TrappedRookPenalty - mob * 16); + ei.value -= Sign[Us] * make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2 + : (TrappedRookPenalty - mob * 16), 0); } } } } + // evaluate_threats<>() assigns bonuses according to the type of attacking piece + // and the type of attacked one. + + template + void evaluate_threats(const Position& pos, EvalInfo& ei) { + + const Color Them = (Us == WHITE ? BLACK : WHITE); + + Bitboard b; + Score bonus = make_score(0, 0); + + // Enemy pieces not defended by a pawn and under our attack + Bitboard weakEnemies = pos.pieces_of_color(Them) + & ~ei.attackedBy[Them][PAWN] + & ei.attackedBy[Us][0]; + if (!weakEnemies) + return; + + // Add bonus according to type of attacked enemy pieces and to the + // type of attacking piece, from knights to queens. Kings are not + // considered because are already special handled in king evaluation. + for (PieceType pt1 = KNIGHT; pt1 < KING; pt1++) + { + b = ei.attackedBy[Us][pt1] & weakEnemies; + if (b) + for (PieceType pt2 = PAWN; pt2 < KING; pt2++) + if (b & pos.pieces(pt2)) + bonus += ThreatBonus[pt1][pt2]; + } + ei.value += Sign[Us] * bonus; + } + + // evaluate_pieces_of_color<>() assigns bonuses and penalties to all the // pieces of a given color. template void evaluate_pieces_of_color(const Position& pos, EvalInfo& ei) { - evaluate_pieces(pos, ei); - evaluate_pieces(pos, ei); - evaluate_pieces(pos, ei); - evaluate_pieces(pos, ei); + const Color Them = (Us == WHITE ? BLACK : WHITE); + + // Do not include in mobility squares protected by enemy pawns or occupied by our pieces + const Bitboard no_mob_area = ~(ei.attackedBy[Them][PAWN] | pos.pieces_of_color(Us)); + + evaluate_pieces(pos, ei, no_mob_area); + evaluate_pieces(pos, ei, no_mob_area); + evaluate_pieces(pos, ei, no_mob_area); + evaluate_pieces(pos, ei, no_mob_area); - // Sum up all attacked squares - ei.attackedBy[Us][0] = ei.attackedBy[Us][PAWN] | ei.attackedBy[Us][KNIGHT] - | ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK] - | ei.attackedBy[Us][QUEEN] | ei.attackedBy[Us][KING]; + // Sum up all attacked squares + ei.attackedBy[Us][0] = ei.attackedBy[Us][PAWN] | ei.attackedBy[Us][KNIGHT] + | ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK] + | ei.attackedBy[Us][QUEEN] | ei.attackedBy[Us][KING]; } @@ -713,322 +687,280 @@ namespace { void evaluate_king(const Position& pos, EvalInfo& ei) { const Color Them = (Us == WHITE ? BLACK : WHITE); - const Square s = pos.king_square(Us); - int shelter = 0; + + Bitboard undefended, b, b1, b2, safe; + bool sente; + int attackUnits, shelter = 0; + const Square ksq = pos.king_square(Us); // King shelter - if (relative_rank(Us, s) <= RANK_4) + if (relative_rank(Us, ksq) <= RANK_4) { - shelter = ei.pi->get_king_shelter(pos, Us, s); - ei.mgValue += Sign[Us] * Value(shelter); + shelter = ei.pi->get_king_shelter(pos, Us, ksq); + ei.value += Sign[Us] * make_score(shelter, 0); } // King safety. This is quite complicated, and is almost certainly far // from optimally tuned. if ( pos.piece_count(Them, QUEEN) >= 1 - && ei.kingAttackersCount[Them] >= 2 - && pos.non_pawn_material(Them) >= QueenValueMidgame + RookValueMidgame + && ei.kingAttackersCount[Them] >= 2 + && pos.non_pawn_material(Them) >= QueenValueMidgame + RookValueMidgame && ei.kingAdjacentZoneAttacksCount[Them]) { - // Is it the attackers turn to move? - bool sente = (Them == pos.side_to_move()); - - // Find the attacked squares around the king which has no defenders - // apart from the king itself - Bitboard undefended = - ei.attacked_by(Them) & ~ei.attacked_by(Us, PAWN) - & ~ei.attacked_by(Us, KNIGHT) & ~ei.attacked_by(Us, BISHOP) - & ~ei.attacked_by(Us, ROOK) & ~ei.attacked_by(Us, QUEEN) - & ei.attacked_by(Us, KING); - - Bitboard occ = pos.occupied_squares(), b, b2; - - // Initialize the 'attackUnits' variable, which is used later on as an - // index to the SafetyTable[] array. The initial value is based on the - // number and types of the attacking pieces, the number of attacked and - // undefended squares around the king, the square of the king, and the - // quality of the pawn shelter. - int attackUnits = - Min((ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) / 2, 25) - + (ei.kingAdjacentZoneAttacksCount[Them] + count_1s_max_15(undefended)) * 3 - + InitKingDanger[relative_square(Us, s)] - (shelter >> 5); - - // Analyse safe queen contact checks - b = undefended & ei.attacked_by(Them, QUEEN) & ~pos.pieces_of_color(Them); - if (b) - { - Bitboard attackedByOthers = - ei.attacked_by(Them, PAWN) | ei.attacked_by(Them, KNIGHT) - | ei.attacked_by(Them, BISHOP) | ei.attacked_by(Them, ROOK); - - b &= attackedByOthers; + // Is it the attackers turn to move? + sente = (Them == pos.side_to_move()); + + // Find the attacked squares around the king which has no defenders + // apart from the king itself + undefended = ei.attacked_by(Them) & ei.attacked_by(Us, KING); + undefended &= ~( ei.attacked_by(Us, PAWN) | ei.attacked_by(Us, KNIGHT) + | ei.attacked_by(Us, BISHOP) | ei.attacked_by(Us, ROOK) + | ei.attacked_by(Us, QUEEN)); + + // Initialize the 'attackUnits' variable, which is used later on as an + // index to the KingDangerTable[] array. The initial value is based on + // the number and types of the enemy's attacking pieces, the number of + // attacked and undefended squares around our king, the square of the + // king, and the quality of the pawn shelter. + attackUnits = Min(25, (ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) / 2) + + 3 * (ei.kingAdjacentZoneAttacksCount[Them] + count_1s_max_15(undefended)) + + InitKingDanger[relative_square(Us, ksq)] + - shelter / 32; + + // Analyse enemy's safe queen contact checks. First find undefended + // squares around the king attacked by enemy queen... + b = undefended & ei.attacked_by(Them, QUEEN) & ~pos.pieces_of_color(Them); if (b) { - // The bitboard b now contains the squares available for safe queen - // contact checks. - int count = count_1s_max_15(b); - attackUnits += QueenContactCheckBonus * count * (sente ? 2 : 1); - - // Is there a mate threat? - if (QueenContactMates && !pos.is_check()) - { - Bitboard escapeSquares = - pos.attacks_from(s) & ~pos.pieces_of_color(Us) & ~attackedByOthers; - - while (b) - { - Square from, to = pop_1st_bit(&b); - if (!(escapeSquares & ~queen_attacks_bb(to, occ & ClearMaskBB[s]))) - { - // We have a mate, unless the queen is pinned or there - // is an X-ray attack through the queen. - for (int i = 0; i < pos.piece_count(Them, QUEEN); i++) - { - from = pos.piece_list(Them, QUEEN, i); - if ( bit_is_set(pos.attacks_from(from), to) - && !bit_is_set(pos.pinned_pieces(Them), from) - && !(rook_attacks_bb(to, occ & ClearMaskBB[from]) & pos.pieces(ROOK, QUEEN, Us)) - && !(bishop_attacks_bb(to, occ & ClearMaskBB[from]) & pos.pieces(BISHOP, QUEEN, Us))) - - ei.mateThreat[Them] = make_move(from, to); - } - } - } - } + // ...then remove squares not supported by another enemy piece + b &= ( ei.attacked_by(Them, PAWN) | ei.attacked_by(Them, KNIGHT) + | ei.attacked_by(Them, BISHOP) | ei.attacked_by(Them, ROOK)); + if (b) + attackUnits += QueenContactCheckBonus * count_1s_max_15(b) * (sente ? 2 : 1); } - } - // Analyse safe distance checks - if (QueenCheckBonus > 0 || RookCheckBonus > 0) - { - b = pos.attacks_from(s) & ~pos.pieces_of_color(Them) & ~ei.attacked_by(Us); - - // Queen checks - b2 = b & ei.attacked_by(Them, QUEEN); - if (b2) - attackUnits += QueenCheckBonus * count_1s_max_15(b2); - - // Rook checks - b2 = b & ei.attacked_by(Them, ROOK); - if (b2) - attackUnits += RookCheckBonus * count_1s_max_15(b2); - } - if (QueenCheckBonus > 0 || BishopCheckBonus > 0) - { - b = pos.attacks_from(s) & ~pos.pieces_of_color(Them) & ~ei.attacked_by(Us); + // Analyse enemy's safe distance checks for sliders and knights + safe = ~(pos.pieces_of_color(Them) | ei.attacked_by(Us)); - // Queen checks - b2 = b & ei.attacked_by(Them, QUEEN); - if (b2) - attackUnits += QueenCheckBonus * count_1s_max_15(b2); + b1 = pos.attacks_from(ksq) & safe; + b2 = pos.attacks_from(ksq) & safe; - // Bishop checks - b2 = b & ei.attacked_by(Them, BISHOP); - if (b2) - attackUnits += BishopCheckBonus * count_1s_max_15(b2); - } - if (KnightCheckBonus > 0) - { - b = pos.attacks_from(s) & ~pos.pieces_of_color(Them) & ~ei.attacked_by(Us); + // Enemy queen safe checks + b = (b1 | b2) & ei.attacked_by(Them, QUEEN); + if (b) + attackUnits += QueenCheckBonus * count_1s_max_15(b); - // Knight checks - b2 = b & ei.attacked_by(Them, KNIGHT); - if (b2) - attackUnits += KnightCheckBonus * count_1s_max_15(b2); - } + // Enemy rooks safe checks + b = b1 & ei.attacked_by(Them, ROOK); + if (b) + attackUnits += RookCheckBonus * count_1s_max_15(b); - // Analyse discovered checks (only for non-pawns right now, consider - // adding pawns later). - if (DiscoveredCheckBonus) - { - b = pos.discovered_check_candidates(Them) & ~pos.pieces(PAWN); + // Enemy bishops safe checks + b = b2 & ei.attacked_by(Them, BISHOP); if (b) - attackUnits += DiscoveredCheckBonus * count_1s_max_15(b) * (sente ? 2 : 1); - } + attackUnits += BishopCheckBonus * count_1s_max_15(b); - // Has a mate threat been found? We don't do anything here if the - // side with the mating move is the side to move, because in that - // case the mating side will get a huge bonus at the end of the main - // evaluation function instead. - if (ei.mateThreat[Them] != MOVE_NONE) - attackUnits += MateThreatBonus; - - // Ensure that attackUnits is between 0 and 99, in order to avoid array - // out of bounds errors: - if (attackUnits < 0) - attackUnits = 0; - - if (attackUnits >= 100) - attackUnits = 99; - - // Finally, extract the king safety score from the SafetyTable[] array. - // Add the score to the evaluation, and also to ei.futilityMargin. The - // reason for adding the king safety score to the futility margin is - // that the king safety scores can sometimes be very big, and that - // capturing a single attacking piece can therefore result in a score - // change far bigger than the value of the captured piece. - Value v = apply_weight(SafetyTable[attackUnits], WeightKingSafety[Us]); - - ei.mgValue -= Sign[Us] * v; - - if (Us == pos.side_to_move()) - ei.futilityMargin += v; + // Enemy knights safe checks + b = pos.attacks_from(ksq) & ei.attacked_by(Them, KNIGHT) & safe; + if (b) + attackUnits += KnightCheckBonus * count_1s_max_15(b); + + // To index KingDangerTable[] attackUnits must be in [0, 99] range + attackUnits = Min(99, Max(0, attackUnits)); + + // Finally, extract the king danger score from the KingDangerTable[] + // array and subtract the score from evaluation. Set also ei.kingDanger[] + // value that will be used for pruning because this value can sometimes + // be very big, and so capturing a single attacking piece can therefore + // result in a score change far bigger than the value of the captured piece. + ei.value -= Sign[Us] * KingDangerTable[Us][attackUnits]; + ei.kingDanger[Us] = mg_value(KingDangerTable[Us][attackUnits]); } } - // evaluate_passed_pawns() evaluates the passed pawns for both sides + // evaluate_passed_pawns<>() evaluates the passed pawns of the given color + template void evaluate_passed_pawns(const Position& pos, EvalInfo& ei) { - bool hasUnstoppable[2] = {false, false}; - int movesToGo[2] = {100, 100}; + const Color Them = (Us == WHITE ? BLACK : WHITE); - for (Color us = WHITE; us <= BLACK; us++) + Bitboard squaresToQueen, defendedSquares, unsafeSquares, supportingPawns; + Bitboard b = ei.pi->passed_pawns() & pos.pieces_of_color(Us); + + while (b) { - Color them = opposite_color(us); - Square ourKingSq = pos.king_square(us); - Square theirKingSq = pos.king_square(them); - Bitboard b = ei.pi->passed_pawns() & pos.pieces(PAWN, us), b2, b3, b4; + Square s = pop_1st_bit(&b); - while (b) - { - Square s = pop_1st_bit(&b); + assert(pos.pawn_is_passed(Us, s)); - assert(pos.piece_on(s) == piece_of_color_and_type(us, PAWN)); - assert(pos.pawn_is_passed(us, s)); + int r = int(relative_rank(Us, s) - RANK_2); + int tr = r * (r - 1); - int r = int(relative_rank(us, s) - RANK_2); - int tr = Max(0, r * (r - 1)); - Square blockSq = s + pawn_push(us); + // Base bonus based on rank + Value mbonus = Value(20 * tr); + Value ebonus = Value(10 + r * r * 10); - // Base bonus based on rank - Value mbonus = Value(20 * tr); - Value ebonus = Value(10 + r * r * 10); + if (tr) + { + Square blockSq = s + pawn_push(Us); - // Adjust bonus based on king proximity - if (tr != 0) + // Adjust bonus based on kings proximity + ebonus -= Value(square_distance(pos.king_square(Us), blockSq) * 3 * tr); + ebonus -= Value(square_distance(pos.king_square(Us), blockSq + pawn_push(Us)) * 1 * tr); + ebonus += Value(square_distance(pos.king_square(Them), blockSq) * 6 * tr); + + // If the pawn is free to advance, increase bonus + if (pos.square_is_empty(blockSq)) { - ebonus -= Value(square_distance(ourKingSq, blockSq) * 3 * tr); - ebonus -= Value(square_distance(ourKingSq, blockSq + pawn_push(us)) * 1 * tr); - ebonus += Value(square_distance(theirKingSq, blockSq) * 6 * tr); + squaresToQueen = squares_in_front_of(Us, s); + defendedSquares = squaresToQueen & ei.attacked_by(Us); + + // If there is an enemy rook or queen attacking the pawn from behind, + // add all X-ray attacks by the rook or queen. Otherwise consider only + // the squares in the pawn's path attacked or occupied by the enemy. + if ( (squares_behind(Us, s) & pos.pieces(ROOK, QUEEN, Them)) + && (squares_behind(Us, s) & pos.pieces(ROOK, QUEEN, Them) & pos.attacks_from(s))) + unsafeSquares = squaresToQueen; + else + unsafeSquares = squaresToQueen & (ei.attacked_by(Them) | pos.pieces_of_color(Them)); - // If the pawn is free to advance, increase bonus - if (pos.square_is_empty(blockSq)) - { - b2 = squares_in_front_of(us, s); - b3 = b2 & ei.attacked_by(them); - b4 = b2 & ei.attacked_by(us); - - // If there is an enemy rook or queen attacking the pawn from behind, - // add all X-ray attacks by the rook or queen. - if ( bit_is_set(ei.attacked_by(them,ROOK) | ei.attacked_by(them,QUEEN),s) - && (squares_behind(us, s) & pos.pieces(ROOK, QUEEN, them))) - b3 = b2; - - // Squares attacked or occupied by enemy pieces - b3 |= (b2 & pos.pieces_of_color(them)); - - // There are no enemy pawns in the pawn's path - assert((b2 & pos.pieces(PAWN, them)) == EmptyBoardBB); - - // Are any of the squares in the pawn's path attacked or occupied by the enemy? - if (b3 == EmptyBoardBB) - // No enemy attacks or pieces, huge bonus! - ebonus += Value(tr * (b2 == b4 ? 17 : 15)); - else - // OK, there are enemy attacks or pieces (but not pawns). Are those - // squares which are attacked by the enemy also attacked by us? - // If yes, big bonus (but smaller than when there are no enemy attacks), - // if no, somewhat smaller bonus. - ebonus += Value(tr * ((b3 & b4) == b3 ? 13 : 8)); - - // At last, add a small bonus when there are no *friendly* pieces - // in the pawn's path. - if ((b2 & pos.pieces_of_color(us)) == EmptyBoardBB) - ebonus += Value(tr); - } + // If there aren't enemy attacks or pieces along the path to queen give + // huge bonus. Even bigger if we protect the pawn's path. + if (!unsafeSquares) + ebonus += Value(tr * (squaresToQueen == defendedSquares ? 17 : 15)); + else + // OK, there are enemy attacks or pieces (but not pawns). Are those + // squares which are attacked by the enemy also attacked by us ? + // If yes, big bonus (but smaller than when there are no enemy attacks), + // if no, somewhat smaller bonus. + ebonus += Value(tr * ((unsafeSquares & defendedSquares) == unsafeSquares ? 13 : 8)); + + // At last, add a small bonus when there are no *friendly* pieces + // in the pawn's path. + if (!(squaresToQueen & pos.pieces_of_color(Us))) + ebonus += Value(tr); } + } // tr != 0 + + // Increase the bonus if the passed pawn is supported by a friendly pawn + // on the same rank and a bit smaller if it's on the previous rank. + supportingPawns = pos.pieces(PAWN, Us) & neighboring_files_bb(s); + if (supportingPawns & rank_bb(s)) + ebonus += Value(r * 20); + else if (supportingPawns & rank_bb(s - pawn_push(Us))) + ebonus += Value(r * 12); + + // Rook pawns are a special case: They are sometimes worse, and + // sometimes better than other passed pawns. It is difficult to find + // good rules for determining whether they are good or bad. For now, + // we try the following: Increase the value for rook pawns if the + // other side has no pieces apart from a knight, and decrease the + // value if the other side has a rook or queen. + if (square_file(s) == FILE_A || square_file(s) == FILE_H) + { + if (pos.non_pawn_material(Them) <= KnightValueMidgame) + ebonus += ebonus / 4; + else if (pos.pieces(ROOK, QUEEN, Them)) + ebonus -= ebonus / 4; + } - // If the pawn is supported by a friendly pawn, increase bonus - b2 = pos.pieces(PAWN, us) & neighboring_files_bb(s); - if (b2 & rank_bb(s)) - ebonus += Value(r * 20); - else if (pos.attacks_from(s, them) & b2) - ebonus += Value(r * 12); + // Add the scores for this pawn to the middle game and endgame eval + ei.value += Sign[Us] * apply_weight(make_score(mbonus, ebonus), Weights[PassedPawns]); - // If the other side has only a king, check whether the pawn is - // unstoppable - if (pos.non_pawn_material(them) == Value(0)) - { - Square qsq; - int d; + } // while + } - qsq = relative_square(us, make_square(square_file(s), RANK_8)); - d = square_distance(s, qsq) - - square_distance(theirKingSq, qsq) - + (us != pos.side_to_move()); - if (d < 0) + // evaluate_unstoppable_pawns() evaluates the unstoppable passed pawns for both sides + + void evaluate_unstoppable_pawns(const Position& pos, EvalInfo& ei) { + + int movesToGo[2] = {0, 0}; + Square pawnToGo[2] = {SQ_NONE, SQ_NONE}; + + for (Color c = WHITE; c <= BLACK; c++) + { + // Skip evaluation if other side has non-pawn pieces + if (pos.non_pawn_material(opposite_color(c))) + continue; + + Bitboard b = ei.pi->passed_pawns() & pos.pieces_of_color(c); + + while (b) + { + Square s = pop_1st_bit(&b); + Square queeningSquare = relative_square(c, make_square(square_file(s), RANK_8)); + int d = square_distance(s, queeningSquare) + - int(relative_rank(c, s) == RANK_2) // Double pawn push + - square_distance(pos.king_square(opposite_color(c)), queeningSquare) + + int(c != pos.side_to_move()); + + // Do we protect the path to queening ? + bool pathDefended = (ei.attacked_by(c) & squares_in_front_of(c, s)) == squares_in_front_of(c, s); + + if (d < 0 || pathDefended) + { + int mtg = RANK_8 - relative_rank(c, s) - int(relative_rank(c, s) == RANK_2); + int blockerCount = count_1s_max_15(squares_in_front_of(c, s) & pos.occupied_squares()); + mtg += blockerCount; + d += blockerCount; + if ((d < 0 || pathDefended) && (!movesToGo[c] || movesToGo[c] > mtg)) { - int mtg = RANK_8 - relative_rank(us, s); - int blockerCount = count_1s_max_15(squares_in_front_of(us,s) & pos.occupied_squares()); - mtg += blockerCount; - d += blockerCount; - if (d < 0) - { - hasUnstoppable[us] = true; - movesToGo[us] = Min(movesToGo[us], mtg); - } + movesToGo[c] = mtg; + pawnToGo[c] = s; } } - // Rook pawns are a special case: They are sometimes worse, and - // sometimes better than other passed pawns. It is difficult to find - // good rules for determining whether they are good or bad. For now, - // we try the following: Increase the value for rook pawns if the - // other side has no pieces apart from a knight, and decrease the - // value if the other side has a rook or queen. - if (square_file(s) == FILE_A || square_file(s) == FILE_H) - { - if ( pos.non_pawn_material(them) <= KnightValueMidgame - && pos.piece_count(them, KNIGHT) <= 1) - ebonus += ebonus / 4; - else if (pos.pieces(ROOK, QUEEN, them)) - ebonus -= ebonus / 4; - } - - // Add the scores for this pawn to the middle game and endgame eval. - ei.mgValue += apply_weight(Sign[us] * mbonus, WeightPassedPawnsMidgame); - ei.egValue += apply_weight(Sign[us] * ebonus, WeightPassedPawnsEndgame); } } - // Does either side have an unstoppable passed pawn? - if (hasUnstoppable[WHITE] && !hasUnstoppable[BLACK]) - ei.egValue += UnstoppablePawnValue - Value(0x40 * movesToGo[WHITE]); - else if (hasUnstoppable[BLACK] && !hasUnstoppable[WHITE]) - ei.egValue -= UnstoppablePawnValue - Value(0x40 * movesToGo[BLACK]); - else if (hasUnstoppable[BLACK] && hasUnstoppable[WHITE]) + // Neither side has an unstoppable passed pawn? + if (!(movesToGo[WHITE] | movesToGo[BLACK])) + return; + + // Does only one side have an unstoppable passed pawn? + if (!movesToGo[WHITE] || !movesToGo[BLACK]) { - // Both sides have unstoppable pawns! Try to find out who queens + Color winnerSide = movesToGo[WHITE] ? WHITE : BLACK; + ei.value += make_score(0, Sign[winnerSide] * (UnstoppablePawnValue - Value(0x40 * movesToGo[winnerSide]))); + } + else + { // Both sides have unstoppable pawns! Try to find out who queens // first. We begin by transforming 'movesToGo' to the number of // plies until the pawn queens for both sides. movesToGo[WHITE] *= 2; movesToGo[BLACK] *= 2; movesToGo[pos.side_to_move()]--; - // If one side queens at least three plies before the other, that - // side wins. - if (movesToGo[WHITE] <= movesToGo[BLACK] - 3) - ei.egValue += UnstoppablePawnValue - Value(0x40 * (movesToGo[WHITE]/2)); - else if (movesToGo[BLACK] <= movesToGo[WHITE] - 3) - ei.egValue -= UnstoppablePawnValue - Value(0x40 * (movesToGo[BLACK]/2)); - - // We could also add some rules about the situation when one side - // queens exactly one ply before the other: Does the first queen - // check the opponent's king, or attack the opponent's queening square? - // This is slightly tricky to get right, because it is possible that - // the opponent's king has moved somewhere before the first pawn queens. + Color winnerSide = movesToGo[WHITE] < movesToGo[BLACK] ? WHITE : BLACK; + Color loserSide = opposite_color(winnerSide); + + // If one side queens at least three plies before the other, that side wins + if (movesToGo[winnerSide] <= movesToGo[loserSide] - 3) + ei.value += Sign[winnerSide] * make_score(0, UnstoppablePawnValue - Value(0x40 * (movesToGo[winnerSide]/2))); + + // If one side queens one ply before the other and checks the king or attacks + // the undefended opponent's queening square, that side wins. To avoid cases + // where the opponent's king could move somewhere before first pawn queens we + // consider only free paths to queen for both pawns. + else if ( !(squares_in_front_of(WHITE, pawnToGo[WHITE]) & pos.occupied_squares()) + && !(squares_in_front_of(BLACK, pawnToGo[BLACK]) & pos.occupied_squares())) + { + assert(movesToGo[loserSide] - movesToGo[winnerSide] == 1); + + Square winnerQSq = relative_square(winnerSide, make_square(square_file(pawnToGo[winnerSide]), RANK_8)); + Square loserQSq = relative_square(loserSide, make_square(square_file(pawnToGo[loserSide]), RANK_8)); + + Bitboard b = pos.occupied_squares(); + clear_bit(&b, pawnToGo[winnerSide]); + clear_bit(&b, pawnToGo[loserSide]); + b = queen_attacks_bb(winnerQSq, b); + + if ( (b & pos.pieces(KING, loserSide)) + ||(bit_is_set(b, loserQSq) && !bit_is_set(ei.attacked_by(loserSide), loserQSq))) + ei.value += Sign[winnerSide] * make_score(0, UnstoppablePawnValue - Value(0x40 * (movesToGo[winnerSide]/2))); + } } } @@ -1049,8 +981,7 @@ namespace { && pos.see(s, b6) < 0 && pos.see(s, b8) < 0) { - ei.mgValue -= Sign[us] * TrappedBishopA7H7Penalty; - ei.egValue -= Sign[us] * TrappedBishopA7H7Penalty; + ei.value -= Sign[us] * TrappedBishopA7H7Penalty; } } @@ -1084,17 +1015,16 @@ namespace { if (pos.piece_on(b2) == pawn) { - Value penalty; + Score penalty; if (!pos.square_is_empty(b3)) - penalty = 2*TrappedBishopA1H1Penalty; + penalty = 2 * TrappedBishopA1H1Penalty; else if (pos.piece_on(c3) == pawn) penalty = TrappedBishopA1H1Penalty; else penalty = TrappedBishopA1H1Penalty / 2; - ei.mgValue -= Sign[us] * penalty; - ei.egValue -= Sign[us] * penalty; + ei.value -= Sign[us] * penalty; } } @@ -1106,105 +1036,87 @@ namespace { // twice. Finally, the space bonus is scaled by a weight taken from the // material hash table. template - void evaluate_space(const Position& pos, EvalInfo& ei) { + int evaluate_space(const Position& pos, EvalInfo& ei) { const Color Them = (Us == WHITE ? BLACK : WHITE); // Find the safe squares for our pieces inside the area defined by // SpaceMask[us]. A square is unsafe if it is attacked by an enemy // pawn, or if it is undefended and attacked by an enemy piece. + Bitboard safe = SpaceMask[Us] + & ~pos.pieces(PAWN, Us) + & ~ei.attacked_by(Them, PAWN) + & (ei.attacked_by(Us) | ~ei.attacked_by(Them)); - Bitboard safeSquares = SpaceMask[Us] - & ~pos.pieces(PAWN, Us) - & ~ei.attacked_by(Them, PAWN) - & ~(~ei.attacked_by(Us) & ei.attacked_by(Them)); - - // Find all squares which are at most three squares behind some friendly - // pawn. - Bitboard behindFriendlyPawns = pos.pieces(PAWN, Us); - behindFriendlyPawns |= (Us == WHITE ? behindFriendlyPawns >> 8 : behindFriendlyPawns << 8); - behindFriendlyPawns |= (Us == WHITE ? behindFriendlyPawns >> 16 : behindFriendlyPawns << 16); - - int space = count_1s_max_15(safeSquares) - + count_1s_max_15(behindFriendlyPawns & safeSquares); + // Find all squares which are at most three squares behind some friendly pawn + Bitboard behind = pos.pieces(PAWN, Us); + behind |= (Us == WHITE ? behind >> 8 : behind << 8); + behind |= (Us == WHITE ? behind >> 16 : behind << 16); - ei.mgValue += Sign[Us] * apply_weight(Value(space * ei.mi->space_weight()), WeightSpace); + return count_1s_max_15(safe) + count_1s_max_15(behind & safe); } - // apply_weight() applies an evaluation weight to a value + // apply_weight() applies an evaluation weight to a value trying to prevent overflow - inline Value apply_weight(Value v, int w) { - return (v*w) / 0x100; + inline Score apply_weight(Score v, Score w) { + return make_score((int(mg_value(v)) * mg_value(w)) / 0x100, (int(eg_value(v)) * eg_value(w)) / 0x100); } - // scale_by_game_phase() interpolates between a middle game and an endgame - // score, based on game phase. It also scales the return value by a - // ScaleFactor array. + // scale_by_game_phase() interpolates between a middle game and an endgame score, + // based on game phase. It also scales the return value by a ScaleFactor array. - Value scale_by_game_phase(Value mv, Value ev, Phase ph, const ScaleFactor sf[]) { + Value scale_by_game_phase(const Score& v, Phase ph, const ScaleFactor sf[]) { - assert(mv > -VALUE_INFINITE && mv < VALUE_INFINITE); - assert(ev > -VALUE_INFINITE && ev < VALUE_INFINITE); + assert(mg_value(v) > -VALUE_INFINITE && mg_value(v) < VALUE_INFINITE); + assert(eg_value(v) > -VALUE_INFINITE && eg_value(v) < VALUE_INFINITE); assert(ph >= PHASE_ENDGAME && ph <= PHASE_MIDGAME); - ev = apply_scale_factor(ev, sf[(ev > Value(0) ? WHITE : BLACK)]); + Value eg = eg_value(v); + ScaleFactor f = sf[eg > VALUE_ZERO ? WHITE : BLACK]; + Value ev = Value((eg * int(f)) / SCALE_FACTOR_NORMAL); - Value result = Value(int((mv * ph + ev * (128 - ph)) / 128)); - return Value(int(result) & ~(GrainSize - 1)); + int result = (mg_value(v) * int(ph) + ev * int(128 - ph)) / 128; + return Value(result & ~(GrainSize - 1)); } // weight_option() computes the value of an evaluation weight, by combining - // an UCI-configurable weight with an internal weight. + // two UCI-configurable weights (midgame and endgame) with an internal weight. - int weight_option(const std::string& opt, int internalWeight) { + Score weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight) { - int uciWeight = get_option_value_int(opt); - uciWeight = (uciWeight * 0x100) / 100; - return (uciWeight * internalWeight) / 0x100; - } + // Scale option value from 100 to 256 + int mg = get_option_value_int(mgOpt) * 256 / 100; + int eg = get_option_value_int(egOpt) * 256 / 100; + return apply_weight(make_score(mg, eg), internalWeight); + } // init_safety() initizes the king safety evaluation, based on UCI - // parameters. It is called from read_weights(). + // parameters. It is called from read_weights(). void init_safety() { - QueenContactCheckBonus = get_option_value_int("Queen Contact Check Bonus"); - QueenCheckBonus = get_option_value_int("Queen Check Bonus"); - RookCheckBonus = get_option_value_int("Rook Check Bonus"); - BishopCheckBonus = get_option_value_int("Bishop Check Bonus"); - KnightCheckBonus = get_option_value_int("Knight Check Bonus"); - DiscoveredCheckBonus = get_option_value_int("Discovered Check Bonus"); - MateThreatBonus = get_option_value_int("Mate Threat Bonus"); - - int maxSlope = get_option_value_int("King Safety Max Slope"); - int peak = get_option_value_int("King Safety Max Value") * 256 / 100; - double a = get_option_value_int("King Safety Coefficient") / 100.0; - double b = get_option_value_int("King Safety X Intercept"); - bool quad = (get_option_value_string("King Safety Curve") == "Quadratic"); - bool linear = (get_option_value_string("King Safety Curve") == "Linear"); + const Value MaxSlope = Value(30); + const Value Peak = Value(1280); + Value t[100]; + // First setup the base table for (int i = 0; i < 100; i++) { - if (i < b) - SafetyTable[i] = Value(0); - else if (quad) - SafetyTable[i] = Value((int)(a * (i - b) * (i - b))); - else if (linear) - SafetyTable[i] = Value((int)(100 * a * (i - b))); - } + t[i] = Value(int(0.4 * i * i)); - for (int i = 0; i < 100; i++) - { - if (SafetyTable[i+1] - SafetyTable[i] > maxSlope) - for (int j = i + 1; j < 100; j++) - SafetyTable[j] = SafetyTable[j-1] + Value(maxSlope); + if (i > 0) + t[i] = Min(t[i], t[i - 1] + MaxSlope); - if (SafetyTable[i] > Value(peak)) - SafetyTable[i] = Value(peak); + t[i] = Min(t[i], Peak); } + + // Then apply the weights and get the final KingDangerTable[] array + for (Color c = WHITE; c <= BLACK; c++) + for (int i = 0; i < 100; i++) + KingDangerTable[c][i] = apply_weight(make_score(t[i], 0), Weights[KingDangerUs + c]); } }