X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fevaluate.cpp;h=65fd691ada7e3b55f8c203f3c8b76fa5fe391109;hb=4a6d59c6c7caa8a9055197280ea7bdcd072feeaa;hp=82edeec8ac0c43b666ea6df70d728da0989b62b9;hpb=941d923bf81128e5420ffe3dcf0116bf7758f430;p=stockfish diff --git a/src/evaluate.cpp b/src/evaluate.cpp index 82edeec8..37cdce99 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) 2008-2015 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 @@ -17,1319 +17,882 @@ along with this program. If not, see . */ - -//// -//// Includes -//// - +#include #include -#include +#include // For std::memset +#include +#include #include "bitcount.h" #include "evaluate.h" #include "material.h" #include "pawns.h" -#include "scale.h" -#include "thread.h" -#include "ucioption.h" - - -//// -//// Local definitions -//// namespace { - const int Sign[2] = { 1, -1 }; - - // Evaluation grain size, must be a power of 2 - const int GrainSize = 8; - - // Evaluation weights, initialized from UCI options - int WeightMobilityMidgame, WeightMobilityEndgame; - int WeightPawnStructureMidgame, WeightPawnStructureEndgame; - int WeightPassedPawnsMidgame, WeightPassedPawnsEndgame; - int WeightKingSafety[2]; - int WeightSpace; - - // Internal evaluation weights. These are applied on top of the evaluation - // weights read from UCI parameters. The purpose is to be able to change - // the evaluation weights while keeping the default values of the UCI - // 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; - - // 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) - }; + namespace Tracing { - 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) - }; + enum Term { // First 8 entries are for PieceType + MATERIAL = 8, IMBALANCE, MOBILITY, THREAT, PASSED, SPACE, TOTAL, TERM_NB + }; - // 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) - }; + Score scores[COLOR_NB][TERM_NB]; - 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) - }; + std::ostream& operator<<(std::ostream& os, Term idx); - // 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) - }; + double to_cp(Value v); + void write(int idx, Color c, Score s); + void write(int idx, Score w, Score b = SCORE_ZERO); + std::string do_trace(const Position& pos); + } - 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) - }; - // 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) + // Struct EvalInfo contains various information computed and collected + // by the evaluation functions. + struct EvalInfo { + + // Pointers to material and pawn hash table entries + Material::Entry* mi; + Pawns::Entry* pi; + + // attackedBy[color][piece type] is a bitboard representing all squares + // attacked by a given color and piece type, attackedBy[color][ALL_PIECES] + // contains all squares attacked by the given color. + Bitboard attackedBy[COLOR_NB][PIECE_TYPE_NB]; + + // kingRing[color] is the zone around the king which is considered + // by the king safety evaluation. This consists of the squares directly + // adjacent to the king, and the three (or two, for a king on an edge file) + // squares two ranks in front of the king. For instance, if black's king + // is on g8, kingRing[BLACK] is a bitboard containing the squares f8, h8, + // f7, g7, h7, f6, g6 and h6. + Bitboard kingRing[COLOR_NB]; + + // kingAttackersCount[color] is the number of pieces of the given color + // which attack a square in the kingRing of the enemy king. + int kingAttackersCount[COLOR_NB]; + + // kingAttackersWeight[color] is the sum of the "weight" of the pieces of the + // given color which attack a square in the kingRing of the enemy king. The + // weights of the individual piece types are given by the elements in the + // KingAttackWeights array. + int kingAttackersWeight[COLOR_NB]; + + // kingAdjacentZoneAttacksCount[color] is the number of attacks by the given + // color to squares directly adjacent to the enemy king. Pieces which attack + // more than one square are counted multiple times. For instance, if there is + // a white knight on g5 and black's king is on g8, this white knight adds 2 + // to kingAdjacentZoneAttacksCount[WHITE]. + int kingAdjacentZoneAttacksCount[COLOR_NB]; + + Bitboard pinnedPieces[COLOR_NB]; }; - 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) - }; - // Outpost bonuses for knights and bishops, indexed by square (from white's - // point of view). - const Value KnightOutpostBonus[64] = { - // A B C D E F G H - V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // 1 - V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // 2 - V(0), V(0), V(4), V(8), V(8), V(4), V(0), V(0), // 3 - V(0), V(4),V(17),V(26),V(26),V(17), V(4), V(0), // 4 - V(0), V(8),V(26),V(35),V(35),V(26), V(8), V(0), // 5 - V(0), V(4),V(17),V(17),V(17),V(17), V(4), V(0), // 6 - V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // 7 - V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0) // 8 - }; + // Evaluation weights, indexed by the corresponding evaluation term + enum { Mobility, PawnStructure, PassedPawns, Space, KingSafety }; - const Value BishopOutpostBonus[64] = { - // A B C D E F G H - V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // 1 - V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // 2 - V(0), V(0), V(5), V(5), V(5), V(5), V(0), V(0), // 3 - V(0), V(5),V(10),V(10),V(10),V(10), V(5), V(0), // 4 - V(0),V(10),V(21),V(21),V(21),V(21),V(10), V(0), // 5 - V(0), V(5), V(8), V(8), V(8), V(8), V(5), V(0), // 6 - V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // 7 - V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0) // 8 + const struct Weight { int mg, eg; } Weights[] = { + {289, 344}, {233, 201}, {221, 273}, {46, 0}, {322, 0} }; - // Bonus for unstoppable passed pawns - const Value UnstoppablePawnValue = Value(0x500); + Score operator*(Score s, const Weight& w) { + return make_score(mg_value(s) * w.mg / 256, eg_value(s) * w.eg / 256); + } - // 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); - // Rooks on open files (modified by Joona Kiiski) - const Value RookOpenFileBonus = Value(43); - const Value RookHalfOpenFileBonus = Value(19); + #define V(v) Value(v) + #define S(mg, eg) make_score(mg, eg) + + // MobilityBonus[PieceType][attacked] contains bonuses for middle and end + // game, indexed by piece type and number of attacked squares not occupied by + // friendly pieces. + const Score MobilityBonus[][32] = { + {}, {}, + { S(-68,-49), S(-46,-33), S(-3,-12), S( 5, -4), S( 9, 11), S(15, 16), // Knights + S( 23, 27), S( 33, 28), S(37, 29) }, + { S(-49,-44), S(-23,-16), S(16, 1), S(29, 16), S(40, 25), S(51, 34), // Bishops + S( 55, 43), S( 61, 49), S(64, 51), S(68, 52), S(73, 55), S(75, 60), + S( 80, 65), S( 86, 66) }, + { S(-50,-57), S(-28,-22), S(-11, 7), S(-1, 29), S( 0, 39), S( 1, 46), // Rooks + S( 10, 66), S( 16, 79), S(22, 86), S(23,103), S(30,109), S(33,111), + S( 37,115), S( 38,119), S(48,124) }, + { S(-43,-30), S(-27,-15), S( 1, -5), S( 2, -3), S(14, 10), S(18, 24), // Queens + S( 20, 27), S( 33, 37), S(33, 38), S(34, 43), S(40, 46), S(43, 56), + S( 46, 61), S( 52, 63), S(52, 63), S(57, 65), S(60, 70), S(61, 74), + S( 67, 80), S( 76, 82), S(77, 88), S(82, 94), S(86, 95), S(90, 96), + S( 94, 99), S( 96,100), S(99,111), S(99,112) } + }; - // Penalty for rooks trapped inside a friendly king which has lost the - // right to castle. - const Value TrappedRookPenalty = Value(180); + // Outpost[knight/bishop][supported by pawn] contains bonuses for knights and bishops + // outposts, bigger if outpost piece is supported by a pawn. + const Score Outpost[][2] = { + { S(28, 7), S(42,11) }, // Knights + { S(12, 3), S(18, 5) } // Bishops + }; - // Penalty for a bishop on a7/h7 (a2/h2 for black) which is trapped by - // enemy pawns. - const Value TrappedBishopA7H7Penalty = Value(300); + // Threat[defended/weak][minor/major attacking][attacked PieceType] contains + // bonuses according to which piece type attacks which one. + const Score Threat[][2][PIECE_TYPE_NB] = { + { { S(0, 0), S( 0, 0), S(19, 37), S(24, 37), S(44, 97), S(35,106) }, // Defended Minor + { S(0, 0), S( 0, 0), S( 9, 14), S( 9, 14), S( 7, 14), S(24, 48) } }, // Defended Major + { { S(0, 0), S( 0,32), S(33, 41), S(31, 50), S(41,100), S(35,104) }, // Weak Minor + { S(0, 0), S( 0,27), S(26, 57), S(26, 57), S(0 , 43), S(23, 51) } } // Weak Major + }; - // Bitboard masks for detecting trapped bishops on a7/h7 (a2/h2 for black) - const Bitboard MaskA7H7[2] = { - ((1ULL << SQ_A7) | (1ULL << SQ_H7)), - ((1ULL << SQ_A2) | (1ULL << SQ_H2)) + // ThreatenedByPawn[PieceType] contains a penalty according to which piece + // type is attacked by an enemy pawn. + const Score ThreatenedByPawn[PIECE_TYPE_NB] = { + S(0, 0), S(0, 0), S(107, 138), S(84, 122), S(114, 203), S(121, 217) }; + const Score ThreatenedByHangingPawn = S(40, 60); + + // Assorted bonuses and penalties used by evaluation + const Score KingOnOne = S( 2, 58); + const Score KingOnMany = S( 6,125); + const Score RookOnPawn = S( 7, 27); + const Score RookOnOpenFile = S(43, 21); + const Score RookOnSemiOpenFile = S(19, 10); + const Score BishopPawns = S( 8, 12); + const Score MinorBehindPawn = S(16, 0); + const Score TrappedRook = S(92, 0); + const Score Unstoppable = S( 0, 20); + const Score Hanging = S(31, 26); + const Score PawnAttackThreat = S(20, 20); + const Score PawnSafePush = S( 5, 5); + // 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 TrappedBishopA1H1 = S(50, 50); - // Bitboard masks for detecting trapped bishops on a1/h1 (a8/h8 for black) - const Bitboard MaskA1H1[2] = { - ((1ULL << SQ_A1) | (1ULL << SQ_H1)), - ((1ULL << SQ_A8) | (1ULL << SQ_H8)) - }; + #undef S + #undef V - // 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 + // SpaceMask[Color] contains the area of the board which is considered + // by the space evaluation. In the middlegame, each side is given a bonus // based on how many squares inside this area are safe and available for // friendly minor pieces. - const Bitboard SpaceMask[2] = { - (1ULL< - Value do_evaluate(const Position& pos, EvalInfo& ei, int threadID); - - template - void evaluate_pieces_of_color(const Position& pos, EvalInfo& ei); - - template - void evaluate_king(const Position& pos, EvalInfo& ei); + // init_eval_info() initializes king bitboards for given color adding + // pawn attacks. To be done at the beginning of the evaluation. template - void evaluate_threats(const Position& pos, EvalInfo& ei); - - template - void evaluate_space(const Position& pos, EvalInfo& ei); + void init_eval_info(const Position& pos, EvalInfo& ei) { - void evaluate_passed_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); - void init_safety(); -} + const Color Them = (Us == WHITE ? BLACK : WHITE); + const Square Down = (Us == WHITE ? DELTA_S : DELTA_N); + ei.pinnedPieces[Us] = pos.pinned_pieces(Us); + ei.attackedBy[Us][ALL_PIECES] = ei.attackedBy[Us][PAWN] = ei.pi->pawn_attacks(Us); + Bitboard b = ei.attackedBy[Them][KING] = pos.attacks_from(pos.king_square(Them)); -//// -//// Functions -//// - -/// 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) { - - return CpuHasPOPCNT ? do_evaluate(pos, ei, threadID) - : do_evaluate(pos, ei, threadID); -} - -namespace { - -template -Value do_evaluate(const Position& pos, EvalInfo& ei, int threadID) { - - assert(pos.is_ok()); - assert(threadID >= 0 && threadID < THREAD_MAX); - 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(); - - // 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(); - - // If we have a specialized evaluation function for the current material - // configuration, call it and return - if (ei.mi->specialized_eval_exists()) - 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] = ei.pi->pawn_attacks(WHITE); - ei.attackedBy[BLACK][PAWN] = ei.pi->pawn_attacks(BLACK); - 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; - - // Evaluate pieces - evaluate_pieces_of_color(pos, ei); - evaluate_pieces_of_color(pos, ei); - - // Kings. Kings are evaluated after all other pieces for both sides, - // because we need complete attack information for all pieces when computing - // the king safety evaluation. - evaluate_king(pos, ei); - evaluate_king(pos, ei); - - // Evaluate tactical threats, we need full attack info - evaluate_threats(pos, ei); - evaluate_threats(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. To be called after all attacks - // are computed, included king. - if (ei.pi->passed_pawns()) - evaluate_passed_pawns(pos, ei); - - Phase phase = pos.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) - - ei.mgValue += ei.pi->queenside_storm_value(WHITE) - - ei.pi->kingside_storm_value(BLACK); - - 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); - - // Evaluate space for both sides - if (ei.mi->space_weight() > 0) + // Init king safety tables only if we are going to use them + if (pos.non_pawn_material(Us) >= QueenValueMg) { - evaluate_space(pos, ei); - evaluate_space(pos, ei); + ei.kingRing[Them] = b | shift_bb(b); + b &= ei.attackedBy[Us][PAWN]; + ei.kingAttackersCount[Us] = b ? popcount(b) : 0; + ei.kingAdjacentZoneAttacksCount[Us] = ei.kingAttackersWeight[Us] = 0; } + else + ei.kingRing[Them] = ei.kingAttackersCount[Us] = 0; } - // Mobility - ei.mgValue += apply_weight(ei.mgMobility, WeightMobilityMidgame); - ei.egValue += apply_weight(ei.egMobility, WeightMobilityEndgame); - - // 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)))) - { - ScaleFactor sf; - - // Only the two bishops ? - if ( pos.non_pawn_material(WHITE) == BishopValueMidgame - && pos.non_pawn_material(BLACK) == BishopValueMidgame) - { - // Check for KBP vs KB with only a single pawn that is almost - // certainly a draw or at least two pawns. - bool one_pawn = (pos.piece_count(WHITE, PAWN) + pos.piece_count(BLACK, PAWN) == 1); - sf = one_pawn ? ScaleFactor(8) : ScaleFactor(32); - } - else - // Endgame with opposite-colored bishops, but also other pieces. Still - // a bit drawish, but not as drawish as with only the two bishops. - sf = ScaleFactor(50); - - if (factor[WHITE] == SCALE_FACTOR_NORMAL) - factor[WHITE] = sf; - if (factor[BLACK] == SCALE_FACTOR_NORMAL) - factor[BLACK] = sf; - } - // Interpolate between the middle game and the endgame score - Color stm = pos.side_to_move(); + // evaluate_pieces() assigns bonuses and penalties to the pieces of a given color - Value v = Sign[stm] * scale_by_game_phase(ei.mgValue, ei.egValue, phase, factor); + template + Score evaluate_pieces(const Position& pos, EvalInfo& ei, Score* mobility, Bitboard* mobilityArea) { - return (ei.mateThreat[stm] == MOVE_NONE ? v : 8 * QueenValueMidgame - v); -} + Bitboard b; + Square s; + Score score = SCORE_ZERO; -} // namespace + const PieceType NextPt = (Us == WHITE ? Pt : PieceType(Pt + 1)); + const Color Them = (Us == WHITE ? BLACK : WHITE); + const Square* pl = pos.list(Us); -/// 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? + ei.attackedBy[Us][Pt] = 0; -Value quick_evaluate(const Position &pos) { + while ((s = *pl++) != SQ_NONE) + { + // Find attacked squares, including x-ray attacks for bishops and rooks + b = Pt == BISHOP ? attacks_bb(s, pos.pieces() ^ pos.pieces(Us, QUEEN)) + : Pt == ROOK ? attacks_bb< ROOK>(s, pos.pieces() ^ pos.pieces(Us, ROOK, QUEEN)) + : pos.attacks_from(s); - assert(pos.is_ok()); + if (ei.pinnedPieces[Us] & s) + b &= LineBB[pos.king_square(Us)][s]; - static const - ScaleFactor sf[2] = {SCALE_FACTOR_NORMAL, SCALE_FACTOR_NORMAL}; + ei.attackedBy[Us][ALL_PIECES] |= ei.attackedBy[Us][Pt] |= b; - Value mgv = pos.mg_value(); - Value egv = pos.eg_value(); - Phase ph = pos.game_phase(); - Color stm = pos.side_to_move(); + if (b & ei.kingRing[Them]) + { + ei.kingAttackersCount[Us]++; + ei.kingAttackersWeight[Us] += KingAttackWeights[Pt]; + Bitboard bb = b & ei.attackedBy[Them][KING]; + if (bb) + ei.kingAdjacentZoneAttacksCount[Us] += popcount(bb); + } - return Sign[stm] * scale_by_game_phase(mgv, egv, ph, sf); -} + if (Pt == QUEEN) + b &= ~( ei.attackedBy[Them][KNIGHT] + | ei.attackedBy[Them][BISHOP] + | ei.attackedBy[Them][ROOK]); + int mob = popcount(b & mobilityArea[Us]); -/// init_eval() initializes various tables used by the evaluation function + mobility[Us] += MobilityBonus[Pt][mob]; -void init_eval(int threads) { + if (Pt == BISHOP || Pt == KNIGHT) + { + // Bonus for outpost square + if ( relative_rank(Us, s) >= RANK_4 + && !(pos.pieces(Them, PAWN) & pawn_attack_span(Us, s))) + score += Outpost[Pt == BISHOP][!!(ei.attackedBy[Us][PAWN] & s)]; + + // Bonus when behind a pawn + if ( relative_rank(Us, s) < RANK_5 + && (pos.pieces(PAWN) & (s + pawn_push(Us)))) + score += MinorBehindPawn; + + // Penalty for pawns on same color square of bishop + if (Pt == BISHOP) + score -= BishopPawns * ei.pi->pawns_on_same_color_squares(Us, s); + + // An important Chess960 pattern: A cornered bishop blocked by a friendly + // pawn diagonally in front of it is a very serious problem, especially + // when that pawn is also blocked. + if ( Pt == BISHOP + && pos.is_chess960() + && (s == relative_square(Us, SQ_A1) || s == relative_square(Us, SQ_H1))) + { + Square d = pawn_push(Us) + (file_of(s) == FILE_A ? DELTA_E : DELTA_W); + if (pos.piece_on(s + d) == make_piece(Us, PAWN)) + score -= !pos.empty(s + d + pawn_push(Us)) ? TrappedBishopA1H1 * 4 + : pos.piece_on(s + d + d) == make_piece(Us, PAWN) ? TrappedBishopA1H1 * 2 + : TrappedBishopA1H1; + } + } - assert(threads <= THREAD_MAX); + if (Pt == ROOK) + { + // Bonus for aligning with enemy pawns on the same rank/file + if (relative_rank(Us, s) >= RANK_5) + { + Bitboard alignedPawns = pos.pieces(Them, PAWN) & PseudoAttacks[ROOK][s]; + if (alignedPawns) + score += popcount(alignedPawns) * RookOnPawn; + } - for (int i = 0; i < THREAD_MAX; i++) - { - if (i >= threads) - { - delete PawnTable[i]; - delete MaterialTable[i]; - PawnTable[i] = NULL; - MaterialTable[i] = NULL; - continue; - } - if (!PawnTable[i]) - PawnTable[i] = new PawnInfoTable(PawnTableSize); - if (!MaterialTable[i]) - MaterialTable[i] = new MaterialInfoTable(MaterialTableSize); - } -} + // Bonus when on an open or semi-open file + if (ei.pi->semiopen_file(Us, file_of(s))) + score += ei.pi->semiopen_file(Them, file_of(s)) ? RookOnOpenFile : RookOnSemiOpenFile; + // Penalize when trapped by the king, even more if king cannot castle + if (mob <= 3 && !ei.pi->semiopen_file(Us, file_of(s))) + { + Square ksq = pos.king_square(Us); -/// quit_eval() releases heap-allocated memory at program termination + if ( ((file_of(ksq) < FILE_E) == (file_of(s) < file_of(ksq))) + && (rank_of(ksq) == rank_of(s) || relative_rank(Us, ksq) == RANK_1) + && !ei.pi->semiopen_side(Us, file_of(ksq), file_of(s) < file_of(ksq))) + score -= (TrappedRook - make_score(mob * 22, 0)) * (1 + !pos.can_castle(Us)); + } + } + } -void quit_eval() { + if (Trace) + Tracing::write(Pt, Us, score); - for (int i = 0; i < THREAD_MAX; i++) - { - delete PawnTable[i]; - delete MaterialTable[i]; - PawnTable[i] = NULL; - MaterialTable[i] = NULL; + // Recursively call evaluate_pieces() of next piece type until KING excluded + return score - evaluate_pieces(pos, ei, mobility, mobilityArea); } -} - -/// read_weights() reads evaluation weights from the corresponding UCI parameters + template<> + Score evaluate_pieces(const Position&, EvalInfo&, Score*, Bitboard*) { return SCORE_ZERO; } + template<> + Score evaluate_pieces(const Position&, EvalInfo&, Score*, Bitboard*) { return SCORE_ZERO; } -void read_weights(Color us) { - Color them = opposite_color(us); + // evaluate_king() assigns bonuses and penalties to a king of a given color - 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); + template + Score evaluate_king(const Position& pos, const EvalInfo& ei) { - // 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. - if (get_option_value_bool("UCI_AnalyseMode")) - { - WeightKingSafety[us] = (WeightKingSafety[us] + WeightKingSafety[them]) / 2; - WeightKingSafety[them] = WeightKingSafety[us]; - } - init_safety(); -} + const Color Them = (Us == WHITE ? BLACK : WHITE); + Bitboard undefended, b, b1, b2, safe; + int attackUnits; + const Square ksq = pos.king_square(Us); -namespace { + // King shelter and enemy pawns storm + Score score = ei.pi->king_safety(pos, ksq); - // evaluate_mobility() computes mobility and attacks for every piece + // Main king safety evaluation + if (ei.kingAttackersCount[Them]) + { + // Find the attacked squares around the king which have no defenders + // apart from the king itself + undefended = ei.attackedBy[Them][ALL_PIECES] + & ei.attackedBy[Us][KING] + & ~( ei.attackedBy[Us][PAWN] | ei.attackedBy[Us][KNIGHT] + | ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK] + | ei.attackedBy[Us][QUEEN]); + + // Initialize the 'attackUnits' variable, which is used later on as an + // index into the KingDanger[] 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 and the quality of + // the pawn shelter (current 'score' value). + attackUnits = std::min(74, ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) + + 8 * ei.kingAdjacentZoneAttacksCount[Them] + + 25 * popcount(undefended) + + 11 * (ei.pinnedPieces[Us] != 0) + - mg_value(score) / 8 + - !pos.count(Them) * 60; + + // Analyse the enemy's safe queen contact checks. Firstly, find the + // undefended squares around the king reachable by the enemy queen... + b = undefended & ei.attackedBy[Them][QUEEN] & ~pos.pieces(Them); + if (b) + { + // ...and then remove squares not supported by another enemy piece + b &= ei.attackedBy[Them][PAWN] | ei.attackedBy[Them][KNIGHT] + | ei.attackedBy[Them][BISHOP] | ei.attackedBy[Them][ROOK]; - template - int evaluate_mobility(Bitboard b, Bitboard mob_area, EvalInfo& ei) { + if (b) + attackUnits += QueenContactCheck * popcount(b); + } - 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 }; + // Analyse the enemy's safe rook contact checks. Firstly, find the + // undefended squares around the king reachable by the enemy rooks... + b = undefended & ei.attackedBy[Them][ROOK] & ~pos.pieces(Them); - // Update attack info - ei.attackedBy[Us][Piece] |= b; + // Consider only squares where the enemy's rook gives check + b &= PseudoAttacks[ROOK][ksq]; - // King attacks - if (b & ei.kingZone[Us]) - { - ei.kingAttackersCount[Us]++; - ei.kingAttackersWeight[Us] += AttackWeight[Piece]; - Bitboard bb = (b & ei.attackedBy[Them][KING]); - if (bb) - ei.kingAdjacentZoneAttacksCount[Us] += count_1s_max_15(bb); - } + if (b) + { + // ...and then remove squares not supported by another enemy piece + b &= ( ei.attackedBy[Them][PAWN] | ei.attackedBy[Them][KNIGHT] + | ei.attackedBy[Them][BISHOP]); - // Mobility - int mob = (Piece != QUEEN ? count_1s_max_15(b & mob_area) - : count_1s(b & mob_area)); + if (b) + attackUnits += RookContactCheck * popcount(b); + } - ei.mgMobility += Sign[Us] * MgBonus[Piece][mob]; - ei.egMobility += Sign[Us] * EgBonus[Piece][mob]; - return mob; - } + // Analyse the enemy's safe distance checks for sliders and knights + safe = ~(ei.attackedBy[Us][ALL_PIECES] | pos.pieces(Them)); + b1 = pos.attacks_from(ksq) & safe; + b2 = pos.attacks_from(ksq) & safe; - // evaluate_outposts() evaluates bishop and knight outposts squares + // Enemy queen safe checks + b = (b1 | b2) & ei.attackedBy[Them][QUEEN]; + if (b) + attackUnits += QueenCheck * popcount(b); - template - void evaluate_outposts(const Position& pos, EvalInfo& ei, Square s) { + // Enemy rooks safe checks + b = b1 & ei.attackedBy[Them][ROOK]; + if (b) + attackUnits += RookCheck * popcount(b); - const Color Them = (Us == WHITE ? BLACK : WHITE); + // Enemy bishops safe checks + b = b2 & ei.attackedBy[Them][BISHOP]; + if (b) + attackUnits += BishopCheck * popcount(b); - // Initial bonus based on square - Value bonus = (Piece == BISHOP ? BishopOutpostBonus[relative_square(Us, s)] - : KnightOutpostBonus[relative_square(Us, s)]); + // Enemy knights safe checks + b = pos.attacks_from(ksq) & ei.attackedBy[Them][KNIGHT] & safe; + if (b) + attackUnits += KnightCheck * popcount(b); - // 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 ( pos.pieces(KNIGHT, Them) == EmptyBoardBB - && (SquaresByColorBB[square_color(s)] & pos.pieces(BISHOP, Them)) == EmptyBoardBB) - bonus += bonus + bonus / 2; - else - bonus += bonus / 2; + // Finally, extract the king danger score from the KingDanger[] + // array and subtract the score from evaluation. + score -= KingDanger[std::max(std::min(attackUnits, 399), 0)]; } - ei.mgValue += Sign[Us] * bonus; - ei.egValue += Sign[Us] * bonus; - } + if (Trace) + Tracing::write(KING, Us, score); - // evaluate_pieces<>() assigns bonuses and penalties to the pieces of a given color + return score; + } - template - void evaluate_pieces(const Position& pos, EvalInfo& ei) { - Bitboard b; - Square s, ksq; - int mob; - File f; + // evaluate_threats() assigns bonuses according to the type of attacking piece + // and the type of attacked one. - const Color Them = (Us == WHITE ? BLACK : WHITE); - const Square* ptr = pos.piece_list_begin(Us, Piece); + template + Score evaluate_threats(const Position& pos, const EvalInfo& ei) { - // Do not include in mobility squares protected by enemy pawns or occupied by our pieces - const Bitboard mob_area = ~(ei.attackedBy[Them][PAWN] | pos.pieces_of_color(Us)); + const Color Them = (Us == WHITE ? BLACK : WHITE); + const Square Up = (Us == WHITE ? DELTA_N : DELTA_S); + const Square Left = (Us == WHITE ? DELTA_NW : DELTA_SE); + const Square Right = (Us == WHITE ? DELTA_NE : DELTA_SW); + const Bitboard TRank2BB = (Us == WHITE ? Rank2BB : Rank7BB); + const Bitboard TRank7BB = (Us == WHITE ? Rank7BB : Rank2BB); - while ((s = *ptr++) != SQ_NONE) - { - if (Piece == KNIGHT || Piece == QUEEN) - b = pos.attacks_from(s); - else if (Piece == BISHOP) - b = bishop_attacks_bb(s, pos.occupied_squares() & ~pos.pieces(QUEEN, Us)); - else if (Piece == ROOK) - b = rook_attacks_bb(s, pos.occupied_squares() & ~pos.pieces(ROOK, QUEEN, Us)); - else - assert(false); - - // Attacks and mobility - mob = evaluate_mobility(b, mob_area, ei); - - // 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.mgValue -= Sign[Us] * MidgameThreatedByPawnPenalty[Piece]; - ei.egValue -= Sign[Us] * EndgameThreatedByPawnPenalty[Piece]; - } + enum { Defended, Weak }; + enum { Minor, Major }; - // Bishop and knight outposts squares - if ((Piece == BISHOP || Piece == KNIGHT) && pos.square_is_weak(s, Them)) - evaluate_outposts(pos, ei, s); + Bitboard b, weak, defended, safeThreats; + Score score = SCORE_ZERO; - // Special patterns: trapped bishops on a7/h7/a2/h2 - // and trapped bishops on a1/h1/a8/h8 in Chess960. - if (Piece == BISHOP) - { - if (bit_is_set(MaskA7H7[Us], s)) - evaluate_trapped_bishop_a7h7(pos, s, Us, ei); - - if (Chess960 && bit_is_set(MaskA1H1[Us], s)) - evaluate_trapped_bishop_a1h1(pos, s, Us, ei); - } - - if (Piece == ROOK || Piece == QUEEN) - { - // 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); - } - } + // Non-pawn enemies attacked by a pawn + weak = (pos.pieces(Them) ^ pos.pieces(Them, PAWN)) & ei.attackedBy[Us][PAWN]; - // Special extra evaluation for rooks - if (Piece == ROOK) - { - // Open and half-open files - f = square_file(s); - 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; - } - else - { - ei.mgValue += Sign[Us] * RookHalfOpenFileBonus; - ei.egValue += Sign[Us] * RookHalfOpenFileBonus; - } - } + if (weak) + { + b = pos.pieces(Us, PAWN) & ( ~ei.attackedBy[Them][ALL_PIECES] + | ei.attackedBy[Us][ALL_PIECES]); - // Penalize rooks which are trapped inside a king. Penalize more if - // king has lost right to castle. - if (mob > 6 || ei.pi->file_is_half_open(Us, f)) - continue; + safeThreats = (shift_bb(b) | shift_bb(b)) & weak; - ksq = pos.king_square(Us); + if (weak ^ safeThreats) + score += ThreatenedByHangingPawn; - if ( square_file(ksq) >= FILE_E - && 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_right(Us, square_file(ksq))) - ei.mgValue -= pos.can_castle(Us)? Sign[Us] * ((TrappedRookPenalty - mob * 16) / 2) - : Sign[Us] * (TrappedRookPenalty - mob * 16); - } - 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))) - { - // 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); - } - } + while (safeThreats) + score += ThreatenedByPawn[type_of(pos.piece_on(pop_lsb(&safeThreats)))]; } - } + // Non-pawn enemies defended by a pawn + defended = (pos.pieces(Them) ^ pos.pieces(Them, PAWN)) & ei.attackedBy[Them][PAWN]; - // evaluate_threats<>() assigns bonuses according to the type of attacking piece - // and the type of attacked one. + // Add a bonus according to the kind of attacking pieces + if (defended) + { + b = defended & (ei.attackedBy[Us][KNIGHT] | ei.attackedBy[Us][BISHOP]); + while (b) + score += Threat[Defended][Minor][type_of(pos.piece_on(pop_lsb(&b)))]; - template - void evaluate_threats(const Position& pos, EvalInfo& ei) { + b = defended & (ei.attackedBy[Us][ROOK]); + while (b) + score += Threat[Defended][Major][type_of(pos.piece_on(pop_lsb(&b)))]; + } - const Color Them = (Us == WHITE ? BLACK : WHITE); + // Enemies not defended by a pawn and under our attack + weak = pos.pieces(Them) + & ~ei.attackedBy[Them][PAWN] + & ei.attackedBy[Us][ALL_PIECES]; - Bitboard b; - Value mgBonus = Value(0); - Value egBonus = Value(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++) + // Add a bonus according to the kind of attacking pieces + if (weak) { - b = ei.attackedBy[Us][pt1] & weakEnemies; - if (b) - for (PieceType pt2 = PAWN; pt2 < KING; pt2++) - if (b & pos.pieces(pt2)) - { - mgBonus += MidgameThreatBonus[pt1][pt2]; - egBonus += EndgameThreatBonus[pt1][pt2]; - } - } - ei.mgValue += Sign[Us] * mgBonus; - ei.egValue += Sign[Us] * egBonus; - } + b = weak & (ei.attackedBy[Us][KNIGHT] | ei.attackedBy[Us][BISHOP]); + while (b) + score += Threat[Weak][Minor][type_of(pos.piece_on(pop_lsb(&b)))]; + b = weak & (ei.attackedBy[Us][ROOK] | ei.attackedBy[Us][QUEEN]); + while (b) + score += Threat[Weak][Major][type_of(pos.piece_on(pop_lsb(&b)))]; - // evaluate_pieces_of_color<>() assigns bonuses and penalties to all the - // pieces of a given color. + b = weak & ~ei.attackedBy[Them][ALL_PIECES]; + if (b) + score += Hanging * popcount(b); - template - void evaluate_pieces_of_color(const Position& pos, EvalInfo& ei) { + b = weak & ei.attackedBy[Us][KING]; + if (b) + score += more_than_one(b) ? KingOnMany : KingOnOne; + } - evaluate_pieces(pos, ei); - evaluate_pieces(pos, ei); - evaluate_pieces(pos, ei); - evaluate_pieces(pos, ei); + // Add a small bonus for safe pawn pushes + b = pos.pieces(Us, PAWN) & ~TRank7BB; + b = shift_bb(b | (shift_bb(b & TRank2BB) & ~pos.pieces())); - // 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]; - } + b &= ~pos.pieces() + & ~ei.attackedBy[Them][PAWN] + & (ei.attackedBy[Us][ALL_PIECES] | ~ei.attackedBy[Them][ALL_PIECES]); + if (b) + score += popcount(b) * PawnSafePush; - // evaluate_king<>() assigns bonuses and penalties to a king of a given color + // Add another bonus if the pawn push attacks an enemy piece + b = (shift_bb(b) | shift_bb(b)) + & pos.pieces(Them) + & ~ei.attackedBy[Us][PAWN]; - template - void evaluate_king(const Position& pos, EvalInfo& ei) { + if (b) + score += popcount(b) * PawnAttackThreat; - const Color Them = (Us == WHITE ? BLACK : WHITE); - const Square s = pos.king_square(Us); - int shelter = 0; + if (Trace) + Tracing::write(Tracing::THREAT, Us, score); - // King shelter - if (relative_rank(Us, s) <= RANK_4) - { - shelter = ei.pi->get_king_shelter(pos, Us, s); - ei.mgValue += Sign[Us] * Value(shelter); - } - - // 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.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; - 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); - } - } - } - } - } - } - - // 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); - - // Queen checks - b2 = b & ei.attacked_by(Them, QUEEN); - if (b2) - attackUnits += QueenCheckBonus * count_1s_max_15(b2); - - // 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); - - // Knight checks - b2 = b & ei.attacked_by(Them, KNIGHT); - if (b2) - attackUnits += KnightCheckBonus * count_1s_max_15(b2); - } - - // Analyse discovered checks (only for non-pawns right now, consider - // adding pawns later). - if (DiscoveredCheckBonus) - { - b = pos.discovered_check_candidates(Them) & ~pos.pieces(PAWN); - if (b) - attackUnits += DiscoveredCheckBonus * count_1s_max_15(b) * (sente ? 2 : 1); - } - - // 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; - } + return score; } // evaluate_passed_pawns() evaluates the passed pawns of the given color - template - void evaluate_passed_pawns_of_color(const Position& pos, int movesToGo[], Square pawnToGo[], EvalInfo& ei) { + template + Score evaluate_passed_pawns(const Position& pos, const EvalInfo& ei) { const Color Them = (Us == WHITE ? BLACK : WHITE); - Bitboard b2, b3, b4; - Square ourKingSq = pos.king_square(Us); - Square theirKingSq = pos.king_square(Them); - Bitboard b = ei.pi->passed_pawns() & pos.pieces(PAWN, Us); + Bitboard b, squaresToQueen, defendedSquares, unsafeSquares; + Score score = SCORE_ZERO; + + b = ei.pi->passed_pawns(Us); while (b) { - Square s = pop_1st_bit(&b); + Square s = pop_lsb(&b); - assert(pos.piece_on(s) == piece_of_color_and_type(Us, PAWN)); - assert(pos.pawn_is_passed(Us, s)); + assert(pos.pawn_passed(Us, s)); - int r = int(relative_rank(Us, s) - RANK_2); - int tr = Max(0, r * (r - 1)); + int r = relative_rank(Us, s) - RANK_2; + int rr = r * (r - 1); // Base bonus based on rank - Value mbonus = Value(20 * tr); - Value ebonus = Value(10 + r * r * 10); + Value mbonus = Value(17 * rr), ebonus = Value(7 * (rr + r + 1)); - // Adjust bonus based on king proximity - if (tr) + if (rr) { Square blockSq = s + pawn_push(Us); - 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); + // Adjust bonus based on the king's proximity + ebonus += distance(pos.king_square(Them), blockSq) * 5 * rr + - distance(pos.king_square(Us ), blockSq) * 2 * rr; - // If the pawn is free to advance, increase bonus - if (pos.square_is_empty(blockSq)) + // If blockSq is not the queening square then consider also a second push + if (relative_rank(Us, blockSq) != RANK_8) + ebonus -= distance(pos.king_square(Us), blockSq + pawn_push(Us)) * rr; + + // If the pawn is free to advance, then increase the bonus + if (pos.empty(blockSq)) { - // There are no enemy pawns in the pawn's path - b2 = squares_in_front_of(Us, s); - - assert((b2 & pos.pieces(PAWN, Them)) == EmptyBoardBB); - - // Squares attacked by us - b4 = b2 & ei.attacked_by(Us); - - // Squares attacked or occupied by enemy pieces - b3 = b2 & (ei.attacked_by(Them) | pos.pieces_of_color(Them)); - - // If there is an enemy rook or queen attacking the pawn from behind, - // add all X-ray attacks by the rook or queen. - if ( (squares_behind(Us, s) & pos.pieces(ROOK, QUEEN, Them)) - && (squares_behind(Us, s) & pos.pieces(ROOK, QUEEN, Them) & pos.attacks_from(s))) - b3 = b2; - - // 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! - // Even bigger if we protect the pawn's path - 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); - } - } // tr != 0 - - // 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); - - // 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; + // If there is a rook or queen attacking/defending the pawn from behind, + // consider all the squaresToQueen. Otherwise consider only the squares + // in the pawn's path attacked or occupied by the enemy. + defendedSquares = unsafeSquares = squaresToQueen = forward_bb(Us, s); - 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()); + Bitboard bb = forward_bb(Them, s) & pos.pieces(ROOK, QUEEN) & pos.attacks_from(s); - if (d < 0) - { - 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 && (!movesToGo[Us] || movesToGo[Us] > mtg)) - { - movesToGo[Us] = mtg; - pawnToGo[Us] = s; - } + if (!(pos.pieces(Us) & bb)) + defendedSquares &= ei.attackedBy[Us][ALL_PIECES]; + + if (!(pos.pieces(Them) & bb)) + unsafeSquares &= ei.attackedBy[Them][ALL_PIECES] | pos.pieces(Them); + + // If there aren't any enemy attacks, assign a big bonus. Otherwise + // assign a smaller bonus if the block square isn't attacked. + int k = !unsafeSquares ? 15 : !(unsafeSquares & blockSq) ? 9 : 0; + + // If the path to queen is fully defended, assign a big bonus. + // Otherwise assign a smaller bonus if the block square is defended. + if (defendedSquares == squaresToQueen) + k += 6; + + else if (defendedSquares & blockSq) + k += 4; + + mbonus += k * rr, ebonus += k * rr; } - } + else if (pos.pieces(Us) & blockSq) + mbonus += rr * 3 + r * 2 + 3, ebonus += rr + r * 2; + } // rr != 0 - // 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; - } + if (pos.count(Us) < pos.count(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); + score += make_score(mbonus, ebonus); + } + + if (Trace) + Tracing::write(Tracing::PASSED, Us, score * Weights[PassedPawns]); - } // while + // Add the scores to the middlegame and endgame eval + return score * Weights[PassedPawns]; } - // evaluate_passed_pawns() evaluates the passed pawns for both sides + // evaluate_space() computes the space evaluation for a given side. The + // space evaluation is a simple bonus based on the number of safe squares + // available for minor pieces on the central four files on ranks 2--4. Safe + // squares one, two or three squares behind a friendly pawn are counted + // twice. Finally, the space bonus is multiplied by a weight. The aim is to + // improve play on game opening. + template + Score evaluate_space(const Position& pos, const EvalInfo& ei) { - void evaluate_passed_pawns(const Position& pos, EvalInfo& ei) { + const Color Them = (Us == WHITE ? BLACK : WHITE); - int movesToGo[2] = {0, 0}; - Square pawnToGo[2] = {SQ_NONE, SQ_NONE}; + // Find the safe squares for our pieces inside the area defined by + // SpaceMask[]. 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(Us, PAWN) + & ~ei.attackedBy[Them][PAWN] + & (ei.attackedBy[Us][ALL_PIECES] | ~ei.attackedBy[Them][ALL_PIECES]); - // Evaluate pawns for each color - evaluate_passed_pawns_of_color(pos, movesToGo, pawnToGo, ei); - evaluate_passed_pawns_of_color(pos, movesToGo, pawnToGo, ei); + // Find all squares which are at most three squares behind some friendly pawn + Bitboard behind = pos.pieces(Us, PAWN); + behind |= (Us == WHITE ? behind >> 8 : behind << 8); + behind |= (Us == WHITE ? behind >> 16 : behind << 16); - // Neither side has an unstoppable passed pawn? - if (!(movesToGo[WHITE] | movesToGo[BLACK])) - return; + // Since SpaceMask[Us] is fully on our half of the board + assert(unsigned(safe >> (Us == WHITE ? 32 : 0)) == 0); - // Does only one side have an unstoppable passed pawn? - if (!movesToGo[WHITE] || !movesToGo[BLACK]) - { - Color winnerSide = movesToGo[WHITE] ? WHITE : BLACK; - ei.egValue += 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()]--; - - 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.egValue += Sign[winnerSide] * (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); + // Count safe + (behind & safe) with a single popcount + int bonus = popcount((Us == WHITE ? safe << 32 : safe >> 32) | (behind & safe)); + int weight = pos.count(Us) + pos.count(Us) + + pos.count(Them) + pos.count(Them); - 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)); + return make_score(bonus * weight * weight, 0); + } - 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.egValue += Sign[winnerSide] * (UnstoppablePawnValue - Value(0x40 * (movesToGo[winnerSide]/2))); - } - } - } + // do_evaluate() is the evaluation entry point, called directly from evaluate() + template + Value do_evaluate(const Position& pos) { - // evaluate_trapped_bishop_a7h7() determines whether a bishop on a7/h7 - // (a2/h2 for black) is trapped by enemy pawns, and assigns a penalty - // if it is. + assert(!pos.checkers()); - void evaluate_trapped_bishop_a7h7(const Position& pos, Square s, Color us, EvalInfo &ei) { + EvalInfo ei; + Score score, mobility[2] = { SCORE_ZERO, SCORE_ZERO }; - assert(square_is_ok(s)); - assert(pos.piece_on(s) == piece_of_color_and_type(us, BISHOP)); + // Initialize score by reading the incrementally updated scores included + // in the position object (material + piece square tables). + // Score is computed from the point of view of white. + score = pos.psq_score(); - Square b6 = relative_square(us, (square_file(s) == FILE_A) ? SQ_B6 : SQ_G6); - Square b8 = relative_square(us, (square_file(s) == FILE_A) ? SQ_B8 : SQ_G8); + // Probe the material hash table + ei.mi = Material::probe(pos); + score += ei.mi->imbalance(); - if ( pos.piece_on(b6) == piece_of_color_and_type(opposite_color(us), PAWN) - && pos.see(s, b6, false) < 0 - && pos.see(s, b8, false) < 0) - { - ei.mgValue -= Sign[us] * TrappedBishopA7H7Penalty; - ei.egValue -= Sign[us] * TrappedBishopA7H7Penalty; - } - } + // If we have a specialized evaluation function for the current material + // configuration, call it and return. + if (ei.mi->specialized_eval_exists()) + return ei.mi->evaluate(pos); + // Probe the pawn hash table + ei.pi = Pawns::probe(pos); + score += ei.pi->pawns_score() * Weights[PawnStructure]; - // evaluate_trapped_bishop_a1h1() determines whether a bishop on a1/h1 - // (a8/h8 for black) is trapped by a friendly pawn on b2/g2 (b7/g7 for - // black), and assigns a penalty if it is. This pattern can obviously - // only occur in Chess960 games. + // Initialize attack and king safety bitboards + init_eval_info(pos, ei); + init_eval_info(pos, ei); - void evaluate_trapped_bishop_a1h1(const Position& pos, Square s, Color us, EvalInfo& ei) { + ei.attackedBy[WHITE][ALL_PIECES] |= ei.attackedBy[WHITE][KING]; + ei.attackedBy[BLACK][ALL_PIECES] |= ei.attackedBy[BLACK][KING]; - Piece pawn = piece_of_color_and_type(us, PAWN); - Square b2, b3, c3; + // Pawns blocked or on ranks 2 and 3. Will be excluded from the mobility area + Bitboard blockedPawns[] = { + pos.pieces(WHITE, PAWN) & (shift_bb(pos.pieces()) | Rank2BB | Rank3BB), + pos.pieces(BLACK, PAWN) & (shift_bb(pos.pieces()) | Rank7BB | Rank6BB) + }; - assert(Chess960); - assert(square_is_ok(s)); - assert(pos.piece_on(s) == piece_of_color_and_type(us, BISHOP)); + // Do not include in mobility squares protected by enemy pawns, or occupied + // by our blocked pawns or king. + Bitboard mobilityArea[] = { + ~(ei.attackedBy[BLACK][PAWN] | blockedPawns[WHITE] | pos.king_square(WHITE)), + ~(ei.attackedBy[WHITE][PAWN] | blockedPawns[BLACK] | pos.king_square(BLACK)) + }; - if (square_file(s) == FILE_A) - { - b2 = relative_square(us, SQ_B2); - b3 = relative_square(us, SQ_B3); - c3 = relative_square(us, SQ_C3); - } - else - { - b2 = relative_square(us, SQ_G2); - b3 = relative_square(us, SQ_G3); - c3 = relative_square(us, SQ_F3); - } + // Evaluate pieces and mobility + score += evaluate_pieces(pos, ei, mobility, mobilityArea); + score += (mobility[WHITE] - mobility[BLACK]) * Weights[Mobility]; - if (pos.piece_on(b2) == pawn) - { - Value penalty; + // Evaluate kings after all other pieces because we need complete attack + // information when computing the king safety evaluation. + score += evaluate_king(pos, ei) + - evaluate_king(pos, ei); - if (!pos.square_is_empty(b3)) - penalty = 2*TrappedBishopA1H1Penalty; - else if (pos.piece_on(c3) == pawn) - penalty = TrappedBishopA1H1Penalty; - else - penalty = TrappedBishopA1H1Penalty / 2; + // Evaluate tactical threats, we need full attack information including king + score += evaluate_threats(pos, ei) + - evaluate_threats(pos, ei); - ei.mgValue -= Sign[us] * penalty; - ei.egValue -= Sign[us] * penalty; - } - } + // Evaluate passed pawns, we need full attack information including king + score += evaluate_passed_pawns(pos, ei) + - evaluate_passed_pawns(pos, ei); + // If both sides have only pawns, score for potential unstoppable pawns + if (!pos.non_pawn_material(WHITE) && !pos.non_pawn_material(BLACK)) + { + Bitboard b; + if ((b = ei.pi->passed_pawns(WHITE)) != 0) + score += int(relative_rank(WHITE, frontmost_sq(WHITE, b))) * Unstoppable; - // evaluate_space() computes the space evaluation for a given side. The - // space evaluation is a simple bonus based on the number of safe squares - // available for minor pieces on the central four files on ranks 2--4. Safe - // squares one, two or three squares behind a friendly pawn are counted - // 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) { + if ((b = ei.pi->passed_pawns(BLACK)) != 0) + score -= int(relative_rank(BLACK, frontmost_sq(BLACK, b))) * Unstoppable; + } - const Color Them = (Us == WHITE ? BLACK : WHITE); + // Evaluate space for both sides, only during opening + if (pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) >= 11756) + score += (evaluate_space(pos, ei) - evaluate_space(pos, ei)) * Weights[Space]; - // 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. + // Scale winning side if position is more drawish than it appears + Color strongSide = eg_value(score) > VALUE_DRAW ? WHITE : BLACK; + ScaleFactor sf = ei.mi->scale_factor(pos, strongSide); - Bitboard safeSquares = SpaceMask[Us] - & ~pos.pieces(PAWN, Us) - & ~ei.attacked_by(Them, PAWN) - & ~(~ei.attacked_by(Us) & ei.attacked_by(Them)); + // If we don't already have an unusual scale factor, check for certain + // types of endgames, and use a lower scale for those. + if ( ei.mi->game_phase() < PHASE_MIDGAME + && (sf == SCALE_FACTOR_NORMAL || sf == SCALE_FACTOR_ONEPAWN)) + { + if (pos.opposite_bishops()) + { + // Endgame with opposite-colored bishops and no other pieces (ignoring pawns) + // is almost a draw, in case of KBP vs KB is even more a draw. + if ( pos.non_pawn_material(WHITE) == BishopValueMg + && pos.non_pawn_material(BLACK) == BishopValueMg) + sf = more_than_one(pos.pieces(PAWN)) ? ScaleFactor(32) : ScaleFactor(8); + + // Endgame with opposite-colored bishops, but also other pieces. Still + // a bit drawish, but not as drawish as with only the two bishops. + else + sf = ScaleFactor(50 * sf / SCALE_FACTOR_NORMAL); + } + // Endings where weaker side can place his king in front of the opponent's + // pawns are drawish. + else if ( abs(eg_value(score)) <= BishopValueEg + && ei.pi->pawn_span(strongSide) <= 1 + && !pos.pawn_passed(~strongSide, pos.king_square(~strongSide))) + sf = ei.pi->pawn_span(strongSide) ? ScaleFactor(56) : ScaleFactor(38); + } - // 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); + // Interpolate between a middlegame and a (scaled by 'sf') endgame score + Value v = mg_value(score) * int(ei.mi->game_phase()) + + eg_value(score) * int(PHASE_MIDGAME - ei.mi->game_phase()) * sf / SCALE_FACTOR_NORMAL; - int space = count_1s_max_15(safeSquares) - + count_1s_max_15(behindFriendlyPawns & safeSquares); + v /= int(PHASE_MIDGAME); - ei.mgValue += Sign[Us] * apply_weight(Value(space * ei.mi->space_weight()), WeightSpace); + // In case of tracing add all single evaluation terms for both white and black + if (Trace) + { + Tracing::write(Tracing::MATERIAL, pos.psq_score()); + Tracing::write(Tracing::IMBALANCE, ei.mi->imbalance()); + Tracing::write(PAWN, ei.pi->pawns_score()); + Tracing::write(Tracing::MOBILITY, mobility[WHITE] * Weights[Mobility] + , mobility[BLACK] * Weights[Mobility]); + Tracing::write(Tracing::SPACE, evaluate_space(pos, ei) * Weights[Space] + , evaluate_space(pos, ei) * Weights[Space]); + Tracing::write(Tracing::TOTAL, score); + } + + return (pos.side_to_move() == WHITE ? v : -v) + Eval::Tempo; // Side to move point of view } - // apply_weight() applies an evaluation weight to a value + // Tracing functions + + double Tracing::to_cp(Value v) { return double(v) / PawnValueEg; } + + void Tracing::write(int idx, Color c, Score s) { scores[c][idx] = s; } - inline Value apply_weight(Value v, int w) { - return (v*w) / 0x100; + void Tracing::write(int idx, Score w, Score b) { + scores[WHITE][idx] = w, scores[BLACK][idx] = b; } + std::ostream& Tracing::operator<<(std::ostream& os, Term t) { - // 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. + double wScore[] = { to_cp(mg_value(scores[WHITE][t])), to_cp(eg_value(scores[WHITE][t])) }; + double bScore[] = { to_cp(mg_value(scores[BLACK][t])), to_cp(eg_value(scores[BLACK][t])) }; - Value scale_by_game_phase(Value mv, Value ev, Phase ph, const ScaleFactor sf[]) { + if (t == MATERIAL || t == IMBALANCE || t == Term(PAWN) || t == TOTAL) + os << " --- --- | --- --- | "; + else + os << std::setw(5) << wScore[MG] << " " << std::setw(5) << wScore[EG] << " | " + << std::setw(5) << bScore[MG] << " " << std::setw(5) << bScore[EG] << " | "; - assert(mv > -VALUE_INFINITE && mv < VALUE_INFINITE); - assert(ev > -VALUE_INFINITE && ev < VALUE_INFINITE); - assert(ph >= PHASE_ENDGAME && ph <= PHASE_MIDGAME); + os << std::setw(5) << wScore[MG] - bScore[MG] << " " + << std::setw(5) << wScore[EG] - bScore[EG] << " \n"; - ev = apply_scale_factor(ev, sf[(ev > Value(0) ? WHITE : BLACK)]); + return os; + } - Value result = Value(int((mv * ph + ev * (128 - ph)) / 128)); - return Value(int(result) & ~(GrainSize - 1)); + std::string Tracing::do_trace(const Position& pos) { + + std::memset(scores, 0, sizeof(scores)); + + Value v = do_evaluate(pos); + v = pos.side_to_move() == WHITE ? v : -v; // White's point of view + + std::stringstream ss; + ss << std::showpoint << std::noshowpos << std::fixed << std::setprecision(2) + << " Eval term | White | Black | Total \n" + << " | MG EG | MG EG | MG EG \n" + << "----------------+-------------+-------------+-------------\n" + << " Material | " << Term(MATERIAL) + << " Imbalance | " << Term(IMBALANCE) + << " Pawns | " << Term(PAWN) + << " Knights | " << Term(KNIGHT) + << " Bishop | " << Term(BISHOP) + << " Rooks | " << Term(ROOK) + << " Queens | " << Term(QUEEN) + << " Mobility | " << Term(MOBILITY) + << " King safety | " << Term(KING) + << " Threats | " << Term(THREAT) + << " Passed pawns | " << Term(PASSED) + << " Space | " << Term(SPACE) + << "----------------+-------------+-------------+-------------\n" + << " Total | " << Term(TOTAL); + + ss << "\nTotal Evaluation: " << to_cp(v) << " (white side)\n"; + + return ss.str(); } +} // namespace + - // weight_option() computes the value of an evaluation weight, by combining - // an UCI-configurable weight with an internal weight. +namespace Eval { - int weight_option(const std::string& opt, int internalWeight) { + /// evaluate() is the main evaluation function. It returns a static evaluation + /// of the position always from the point of view of the side to move. - int uciWeight = get_option_value_int(opt); - uciWeight = (uciWeight * 0x100) / 100; - return (uciWeight * internalWeight) / 0x100; + Value evaluate(const Position& pos) { + return do_evaluate(pos); } - // init_safety() initizes the king safety evaluation, based on UCI - // parameters. It is called from read_weights(). + /// trace() is like evaluate(), but instead of returning a value, it returns + /// a string (suitable for outputting to stdout) that contains the detailed + /// descriptions and values of each evaluation term. It's mainly used for + /// debugging. + std::string trace(const Position& pos) { + return Tracing::do_trace(pos); + } - 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"); + /// init() computes evaluation weights, usually at startup - 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"); + void init() { - 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))); - } + const int MaxSlope = 8700; + const int Peak = 1280000; + int t = 0; - for (int i = 0; i < 100; i++) + for (int i = 0; i < 400; ++i) { - if (SafetyTable[i+1] - SafetyTable[i] > maxSlope) - for (int j = i + 1; j < 100; j++) - SafetyTable[j] = SafetyTable[j-1] + Value(maxSlope); - - if (SafetyTable[i] > Value(peak)) - SafetyTable[i] = Value(peak); + t = std::min(Peak, std::min(i * i * 27, t + MaxSlope)); + KingDanger[i] = make_score(t / 1000, 0) * Weights[KingSafety]; } } -} + +} // namespace Eval