X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fevaluate.cpp;h=2903c4b375da81736478ee3fb6439e6f2f749c08;hb=a9b8e8b9318130621acf21f5a2b3a705b63907d3;hp=43ef3c4f66375a0f345fe05423c0b9a156bf8952;hpb=b6ba5f7fe414e95c645fc31a989c1a4ed5fd423d;p=stockfish diff --git a/src/evaluate.cpp b/src/evaluate.cpp index 43ef3c4f..5a28b286 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) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad + Copyright (C) 2008-2014 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 @@ -17,13 +17,10 @@ along with this program. If not, see . */ - -//// -//// Includes -//// - +#include #include -#include +#include +#include #include "bitcount.h" #include "evaluate.h" @@ -32,900 +29,609 @@ #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 - enum { Mobility, PawnStructure, PassedPawns, Space, KingDangerUs, KingDangerThem }; - Score Weights[6]; + // 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 variables + // QueenAttackWeight, RookAttackWeight, BishopAttackWeight and + // KnightAttackWeight in evaluate.cpp + int kingAttackersWeight[COLOR_NB]; + + // kingAdjacentZoneAttacksCount[color] is the number of attacks to squares + // directly adjacent to the king of the given color. Pieces which attack + // more than one square are counted multiple times. For instance, if black's + // king is on g8 and there's a white knight on g5, this knight adds + // 2 to kingAdjacentZoneAttacksCount[BLACK]. + int kingAdjacentZoneAttacksCount[COLOR_NB]; + + Bitboard pinnedPieces[COLOR_NB]; + }; - typedef Value V; - #define S(mg, eg) make_score(mg, eg) + namespace Tracing { - // 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 Score WeightsInternal[] = { - S(248, 271), S(233, 201), S(252, 259), S(46, 0), S(247, 0), S(259, 0) - }; + enum Terms { // First 8 entries are for PieceType + MATERIAL = 8, IMBALANCE, MOBILITY, THREAT, PASSED, SPACE, TOTAL, TERMS_NB + }; - // Knight mobility bonus in middle game and endgame, indexed by the number - // of attacked squares not occupied by friendly piecess. - 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) - }; + Score terms[COLOR_NB][TERMS_NB]; + EvalInfo ei; + ScaleFactor sf; - // 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 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) - }; + double to_cp(Value v); + void add_term(int idx, Score term_w, Score term_b = SCORE_ZERO); + void format_row(std::stringstream& ss, const char* name, int idx); + std::string do_trace(const Position& pos); + } - // 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 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) + // Evaluation weights, indexed by evaluation term + enum { Mobility, PawnStructure, PassedPawns, Space, KingSafety }; + const struct Weight { int mg, eg; } Weights[] = { + {289, 344}, {233, 201}, {221, 273}, {46, 0}, {318, 0} }; - // Queen mobility bonus in middle game and endgame, indexed by the number - // of attacked squares not occupied by friendly pieces. - 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) - }; + typedef Value V; + #define S(mg, eg) make_score(mg, eg) - // 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). - 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 + // 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(-65,-50), S(-42,-30), S(-9,-10), S( 3, 0), S(15, 10), S(27, 20), // Knights + S( 37, 28), S( 42, 31), S(44, 33) }, + { S(-52,-47), S(-28,-23), S( 6, 1), S(20, 15), S(34, 29), S(48, 43), // Bishops + S( 60, 55), S( 68, 63), S(74, 68), S(77, 72), S(80, 75), S(82, 77), + S( 84, 79), S( 86, 81) }, + { S(-47,-53), S(-31,-26), S(-5, 0), S( 1, 16), S( 7, 32), S(13, 48), // Rooks + S( 18, 64), S( 22, 80), S(26, 96), S(29,109), S(31,115), S(33,119), + S( 35,122), S( 36,123), S(37,124) }, + { S(-42,-40), S(-28,-23), S(-5, -7), S( 0, 0), S( 6, 10), S(11, 19), // Queens + S( 13, 29), S( 18, 38), S(20, 40), S(21, 41), S(22, 41), S(22, 41), + S( 22, 41), S( 23, 41), S(24, 41), S(25, 41), S(25, 41), S(25, 41), + S( 25, 41), S( 25, 41), S(25, 41), S(25, 41), S(25, 41), S(25, 41), + S( 25, 41), S( 25, 41), S(25, 41), S(25, 41) } }; - 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 + // Outpost[PieceType][Square] contains bonuses for knights and bishops outposts, + // indexed by piece type and square (from white's point of view). + const Value Outpost[][SQUARE_NB] = { + {// A B C D E F G H + V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // Knights + V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), + V(0), V(0), V(4), V(8), V(8), V(4), V(0), V(0), + V(0), V(4),V(17),V(26),V(26),V(17), V(4), V(0), + V(0), V(8),V(26),V(35),V(35),V(26), V(8), V(0), + V(0), V(4),V(17),V(17),V(17),V(17), V(4), V(0) }, + { + V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // Bishops + V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), + V(0), V(0), V(5), V(5), V(5), V(5), V(0), V(0), + V(0), V(5),V(10),V(10),V(10),V(10), V(5), V(0), + V(0),V(10),V(21),V(21),V(21),V(21),V(10), V(0), + V(0), V(5), V(8), V(8), V(8), V(8), V(5), V(0) } }; - // 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 + // Threat[attacking][attacked] contains bonuses according to which piece + // type attacks which one. + const Score Threat[][PIECE_TYPE_NB] = { + { S(0, 0), S( 7, 39), S(24, 49), S(24, 49), S(41,100), S(41,100) }, // Minor + { S(0, 0), S(15, 39), S(15, 45), S(15, 45), S(15, 45), S(24, 49) } // Major }; - // ThreatedByPawnPenalty[] contains a penalty according to which piece + // ThreatenedByPawn[PieceType] 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) + const Score ThreatenedByPawn[] = { + S(0, 0), S(0, 0), S(80, 119), S(80, 119), S(117, 199), S(127, 218) }; - #undef S - - // Rooks and queens on the 7th rank (modified by Joona Kiiski) - const Score RookOn7thBonus = make_score(47, 98); - const Score QueenOn7thBonus = make_score(27, 54); - - // Rooks on open files (modified by Joona Kiiski) - 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. - const Value TrappedRookPenalty = Value(180); + // Hanging contains a bonus for each enemy hanging piece + const Score Hanging = S(23, 20); - // Penalty for a bishop on a7/h7 (a2/h2 for black) which is trapped by - // enemy pawns. - const Score TrappedBishopA7H7Penalty = make_score(300, 300); + #undef S - // 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)) - }; + const Score RookOnPawn = make_score(10, 28); + const Score RookOpenFile = make_score(43, 21); + const Score RookSemiopenFile = make_score(19, 10); + const Score BishopPawns = make_score( 8, 12); + const Score MinorBehindPawn = make_score(16, 0); + const Score TrappedRook = make_score(92, 0); + const Score Unstoppable = make_score( 0, 20); // 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 Score TrappedBishopA1H1Penalty = make_score(100, 100); - - // 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)) - }; + const Score TrappedBishopA1H1 = make_score(50, 50); - // 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); - - template - void init_attack_tables(const Position& pos, EvalInfo& ei); - - template - void evaluate_pieces_of_color(const Position& pos, EvalInfo& ei); - - template - void evaluate_king(const Position& pos, EvalInfo& ei); - - template - void evaluate_threats(const Position& pos, EvalInfo& ei); - - template - int evaluate_space(const Position& pos, EvalInfo& ei); - - template - 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 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(); -} - - -//// -//// 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) { - - return CpuHasPOPCNT ? do_evaluate(pos, ei) - : do_evaluate(pos, ei); -} - -namespace { - -template -Value do_evaluate(const Position& pos, EvalInfo& ei) { - - ScaleFactor factor[2]; - - assert(pos.is_ok()); - 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.value = pos.value(); - - // Probe the material hash table - 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 - if (ei.mi->specialized_eval_exists()) - return ei.mi->evaluate(pos); - - // After get_material_info() call that modifies them - factor[WHITE] = ei.mi->scale_factor(pos, WHITE); - factor[BLACK] = ei.mi->scale_factor(pos, BLACK); - - // Probe the pawn hash table - 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); - 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 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); - - 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) - - 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) - - 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) - { - int s = evaluate_space(pos, ei) - evaluate_space(pos, ei); - ei.value += apply_weight(make_score(s * ei.mi->space_weight(), 0), Weights[Space]); - } + const int QueenContactCheck = 24; + const int RookContactCheck = 16; + const int QueenCheck = 12; + const int RookCheck = 8; + const int BishopCheck = 2; + const int KnightCheck = 3; + + // KingDanger[attackUnits] contains the actual king danger weighted + // scores, indexed by a calculated integer number. + Score KingDanger[128]; + + const int ScalePawnSpan[2] = { 38, 56 }; + + // apply_weight() weighs score 'v' by weight 'w' trying to prevent overflow + Score apply_weight(Score v, const Weight& w) { + return make_score(mg_value(v) * w.mg / 256, eg_value(v) * w.eg / 256); } - // Mobility - 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 && eg_value(ei.value) > VALUE_ZERO) - || (factor[BLACK] == SCALE_FACTOR_NORMAL && eg_value(ei.value) < VALUE_ZERO))) - { - 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; - } + // init_eval_info() initializes king bitboards for given color adding + // pawn attacks. To be done at the beginning of the evaluation. - // Interpolate between the middle game and the endgame score - return Sign[pos.side_to_move()] * scale_by_game_phase(ei.value, phase, factor); -} - -} // namespace + template + void init_eval_info(const Position& pos, EvalInfo& ei) { -/// init_eval() initializes various tables used by the evaluation function + const Color Them = (Us == WHITE ? BLACK : WHITE); + const Square Down = (Us == WHITE ? DELTA_S : DELTA_N); -void init_eval(int threads) { + ei.pinnedPieces[Us] = pos.pinned_pieces(Us); - assert(threads <= MAX_THREADS); + Bitboard b = ei.attackedBy[Them][KING] = pos.attacks_from(pos.king_square(Them)); + ei.attackedBy[Us][ALL_PIECES] = ei.attackedBy[Us][PAWN] = ei.pi->pawn_attacks(Us); - for (int i = 0; i < MAX_THREADS; i++) - { - if (i >= threads) + // Init king safety tables only if we are going to use them + if (pos.count(Us) && pos.non_pawn_material(Us) > QueenValueMg + PawnValueMg) { - delete PawnTable[i]; - delete MaterialTable[i]; - PawnTable[i] = NULL; - MaterialTable[i] = NULL; - continue; + 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; } - if (!PawnTable[i]) - PawnTable[i] = new PawnInfoTable(PawnTableSize); - if (!MaterialTable[i]) - MaterialTable[i] = new MaterialInfoTable(MaterialTableSize); - } -} - - -/// quit_eval() releases heap-allocated memory at program termination - -void quit_eval() { - - for (int i = 0; i < MAX_THREADS; i++) - { - delete PawnTable[i]; - delete MaterialTable[i]; - PawnTable[i] = NULL; - MaterialTable[i] = NULL; + else + ei.kingRing[Them] = ei.kingAttackersCount[Us] = 0; } -} - - -/// read_weights() reads evaluation weights from the corresponding UCI parameters -void read_weights(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); - - 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 Weights[kingDangerUs] and Weights[kingDangerThem] by their average. - if (get_option_value_bool("UCI_AnalyseMode")) - Weights[kingDangerUs] = Weights[kingDangerThem] = (Weights[kingDangerUs] + Weights[kingDangerThem]) / 2; - - init_safety(); -} - - -namespace { - // init_attack_tables() initializes king bitboards for both sides adding - // pawn attacks. To be done before other evaluations. + // evaluate_outpost() evaluates bishop and knight outpost squares - template - void init_attack_tables(const Position& pos, EvalInfo& ei) { + template + Score evaluate_outpost(const Position& pos, const EvalInfo& ei, Square s) { const Color Them = (Us == WHITE ? BLACK : WHITE); - 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; - } - - - // evaluate_outposts() evaluates bishop and knight outposts squares - - template - void evaluate_outposts(const Position& pos, EvalInfo& ei, Square s) { - - const Color Them = (Us == WHITE ? BLACK : WHITE); + assert (Pt == BISHOP || Pt == KNIGHT); // Initial bonus based on square - Value bonus = (Piece == BISHOP ? BishopOutpostBonus[relative_square(Us, s)] - : KnightOutpostBonus[relative_square(Us, s)]); + Value bonus = Outpost[Pt == BISHOP][relative_square(Us, s)]; // Increase bonus if supported by pawn, especially if the opponent has - // no minor piece which can exchange the outpost piece - if (bonus && bit_is_set(ei.attackedBy[Us][PAWN], s)) + // no minor piece which can trade with the outpost piece. + if (bonus && (ei.attackedBy[Us][PAWN] & s)) { - if ( pos.pieces(KNIGHT, Them) == EmptyBoardBB - && (SquaresByColorBB[square_color(s)] & pos.pieces(BISHOP, Them)) == EmptyBoardBB) + if ( !pos.pieces(Them, KNIGHT) + && !(squares_of_color(s) & pos.pieces(Them, BISHOP))) bonus += bonus + bonus / 2; else bonus += bonus / 2; } - ei.value += Sign[Us] * make_score(bonus, bonus); + + return make_score(bonus, bonus); } - // evaluate_pieces<>() assigns bonuses and penalties to the pieces of a given color + // evaluate_pieces() assigns bonuses and penalties to the pieces of a given color - template - void evaluate_pieces(const Position& pos, EvalInfo& ei, Bitboard no_mob_area) { + template + Score evaluate_pieces(const Position& pos, EvalInfo& ei, Score* mobility, Bitboard* mobilityArea) { Bitboard b; - Square s, ksq; - int mob; - File f; + Square s; + Score score = SCORE_ZERO; + const PieceType NextPt = (Us == WHITE ? Pt : PieceType(Pt + 1)); const Color Them = (Us == WHITE ? BLACK : WHITE); - const Square* ptr = pos.piece_list_begin(Us, Piece); + const Square* pl = pos.list(Us); - while ((s = *ptr++) != SQ_NONE) + ei.attackedBy[Us][Pt] = 0; + + while ((s = *pl++) != SQ_NONE) { // Find attacked squares, including x-ray attacks for bishops and rooks - 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); + 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); - // Update attack info - ei.attackedBy[Us][Piece] |= b; + if (ei.pinnedPieces[Us] & s) + b &= LineBB[pos.king_square(Us)][s]; - // King attacks - if (b & ei.kingZone[Us]) + ei.attackedBy[Us][ALL_PIECES] |= ei.attackedBy[Us][Pt] |= b; + + if (b & ei.kingRing[Them]) { ei.kingAttackersCount[Us]++; - ei.kingAttackersWeight[Us] += KingAttackWeights[Piece]; - Bitboard bb = (b & ei.attackedBy[Them][KING]); + ei.kingAttackersWeight[Us] += KingAttackWeights[Pt]; + Bitboard bb = b & ei.attackedBy[Them][KING]; if (bb) - ei.kingAdjacentZoneAttacksCount[Us] += count_1s_max_15(bb); + ei.kingAdjacentZoneAttacksCount[Us] += popcount(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]; + if (Pt == QUEEN) + b &= ~( ei.attackedBy[Them][KNIGHT] + | ei.attackedBy[Them][BISHOP] + | ei.attackedBy[Them][ROOK]); - // 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, Us)) - evaluate_outposts(pos, ei, s); + int mob = Pt != QUEEN ? popcount(b & mobilityArea[Us]) + : popcount(b & mobilityArea[Us]); - // 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); + mobility[Us] += MobilityBonus[Pt][mob]; - if (Chess960 && bit_is_set(MaskA1H1[Us], s)) - evaluate_trapped_bishop_a1h1(pos, s, Us, ei); - } + // Decrease score if we are attacked by an enemy pawn. The remaining part + // of threat evaluation must be done later when we have full attack info. + if (ei.attackedBy[Them][PAWN] & s) + score -= ThreatenedByPawn[Pt]; - // 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) + if (Pt == BISHOP || Pt == KNIGHT) { - ei.value += Sign[Us] * (Piece == ROOK ? RookOn7thBonus : QueenOn7thBonus); + // Penalty for bishop with same colored pawns + if (Pt == BISHOP) + score -= BishopPawns * ei.pi->pawns_on_same_color_squares(Us, s); + + // Bishop and knight outpost square + if (!(pos.pieces(Them, PAWN) & pawn_attack_span(Us, s))) + score += evaluate_outpost(pos, ei, s); + + // Bishop or knight behind a pawn + if ( relative_rank(Us, s) < RANK_5 + && (pos.pieces(PAWN) & (s + pawn_push(Us)))) + score += MinorBehindPawn; } - // Special extra evaluation for rooks - if (Piece == ROOK) + if (Pt == ROOK) { - // Open and half-open files - f = square_file(s); - if (ei.pi->file_is_half_open(Us, f)) + // Rook piece attacking enemy pawns on the same rank/file + if (relative_rank(Us, s) >= RANK_5) { - if (ei.pi->file_is_half_open(Them, f)) - ei.value += Sign[Us] * RookOpenFileBonus; - else - ei.value += Sign[Us] * RookHalfOpenFileBonus; + Bitboard pawns = pos.pieces(Them, PAWN) & PseudoAttacks[ROOK][s]; + if (pawns) + score += popcount(pawns) * RookOnPawn; } - // 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)) + // Give a bonus for a rook on a open or semi-open file + if (ei.pi->semiopen_file(Us, file_of(s))) + score += ei.pi->semiopen_file(Them, file_of(s)) ? RookOpenFile : RookSemiopenFile; + + if (mob > 3 || ei.pi->semiopen_file(Us, file_of(s))) continue; - ksq = pos.king_square(Us); + Square ksq = pos.king_square(Us); - 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.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))) - { - // 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.value -= Sign[Us] * make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2 - : (TrappedRookPenalty - mob * 16), 0); - } + // Penalize rooks which are trapped by a king. Penalize more if the + // king has lost its castling capability. + 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)); } - } - } - - - // 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 = SCORE_ZERO; - - // 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]; + // 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; + } } - ei.value += Sign[Us] * bonus; - } - - // evaluate_pieces_of_color<>() assigns bonuses and penalties to all the - // pieces of a given color. + if (Trace) + Tracing::terms[Us][Pt] = score; - template - void evaluate_pieces_of_color(const Position& pos, EvalInfo& 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]; + return score - evaluate_pieces(pos, ei, mobility, mobilityArea); } + template<> + Score evaluate_pieces(const Position&, EvalInfo&, Score*, Bitboard*) { return SCORE_ZERO; } + template<> + Score evaluate_pieces(const Position&, EvalInfo&, Score*, Bitboard*) { return SCORE_ZERO; } + - // evaluate_king<>() assigns bonuses and penalties to a king of a given color + // evaluate_king() assigns bonuses and penalties to a king of a given color - template - void evaluate_king(const Position& pos, EvalInfo& ei) { + template + Score evaluate_king(const Position& pos, const EvalInfo& ei) { const Color Them = (Us == WHITE ? BLACK : WHITE); Bitboard undefended, b, b1, b2, safe; - bool sente; - int attackUnits, shelter = 0; + int attackUnits; const Square ksq = pos.king_square(Us); - // King shelter - if (relative_rank(Us, ksq) <= RANK_4) - { - shelter = ei.pi->get_king_shelter(pos, Us, ksq); - ei.value += Sign[Us] * make_score(shelter, 0); - } + // King shelter and enemy pawns storm + Score score = ei.pi->king_safety(pos, ksq); - // 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]) + // Main king safety evaluation + if (ei.kingAttackersCount[Them]) { - // Is it the attackers turn to move? - sente = (Them == pos.side_to_move()); - - // Find the attacked squares around the king which has no defenders + // Find the attacked squares around the king which have 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)); + 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 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); + // index to 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(20, (ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) / 2) + + 3 * (ei.kingAdjacentZoneAttacksCount[Them] + popcount(undefended)) + + 2 * (ei.pinnedPieces[Us] != 0) + - mg_value(score) / 32; + + // Analyse the enemy's safe queen contact checks. Firstly, find the + // undefended squares around the king that are attacked by the enemy's + // queen... + b = undefended & ei.attackedBy[Them][QUEEN] & ~pos.pieces(Them); if (b) { - // ...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)); + // ...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]); + if (b) - attackUnits += QueenContactCheckBonus * count_1s_max_15(b) * (sente ? 2 : 1); + attackUnits += QueenContactCheck * popcount(b); } - // Analyse enemy's safe distance checks for sliders and knights - safe = ~(pos.pieces_of_color(Them) | ei.attacked_by(Us)); + // Analyse the enemy's safe rook contact checks. Firstly, find the + // undefended squares around the king that are attacked by the enemy's + // rooks... + b = undefended & ei.attackedBy[Them][ROOK] & ~pos.pieces(Them); + + // Consider only squares where the enemy's rook gives check + b &= PseudoAttacks[ROOK][ksq]; + + 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][QUEEN]); + + if (b) + attackUnits += RookContactCheck * popcount(b); + } + + // Analyse the enemy's safe distance checks for sliders and knights + safe = ~(pos.pieces(Them) | ei.attackedBy[Us][ALL_PIECES]); b1 = pos.attacks_from(ksq) & safe; b2 = pos.attacks_from(ksq) & safe; // Enemy queen safe checks - b = (b1 | b2) & ei.attacked_by(Them, QUEEN); + b = (b1 | b2) & ei.attackedBy[Them][QUEEN]; if (b) - attackUnits += QueenCheckBonus * count_1s_max_15(b); + attackUnits += QueenCheck * popcount(b); // Enemy rooks safe checks - b = b1 & ei.attacked_by(Them, ROOK); + b = b1 & ei.attackedBy[Them][ROOK]; if (b) - attackUnits += RookCheckBonus * count_1s_max_15(b); + attackUnits += RookCheck * popcount(b); // Enemy bishops safe checks - b = b2 & ei.attacked_by(Them, BISHOP); + b = b2 & ei.attackedBy[Them][BISHOP]; if (b) - attackUnits += BishopCheckBonus * count_1s_max_15(b); + attackUnits += BishopCheck * popcount(b); // Enemy knights safe checks - b = pos.attacks_from(ksq) & ei.attacked_by(Them, KNIGHT) & safe; + b = pos.attacks_from(ksq) & ei.attackedBy[Them][KNIGHT] & safe; + if (b) + attackUnits += KnightCheck * popcount(b); + + // To index KingDanger[] attackUnits must be in [0, 99] range + attackUnits = std::min(99, std::max(0, attackUnits)); + + // Finally, extract the king danger score from the KingDanger[] + // array and subtract the score from evaluation. + score -= KingDanger[attackUnits]; + } + + if (Trace) + Tracing::terms[Us][KING] = score; + + return score; + } + + + // evaluate_threats() assigns bonuses according to the type of attacking piece + // and the type of attacked one. + + template + Score evaluate_threats(const Position& pos, const EvalInfo& ei) { + + const Color Them = (Us == WHITE ? BLACK : WHITE); + + Bitboard b, weakEnemies, protectedEnemies; + Score score = SCORE_ZERO; + + // Protected enemies + protectedEnemies = (pos.pieces(Them) ^ pos.pieces(Them,PAWN)) + & ei.attackedBy[Them][PAWN] + & (ei.attackedBy[Us][KNIGHT] | ei.attackedBy[Us][BISHOP]); + + if(protectedEnemies) + score += Threat[0][type_of(pos.piece_on(lsb(protectedEnemies)))]; + + // Enemies not defended by a pawn and under our attack + weakEnemies = pos.pieces(Them) + & ~ei.attackedBy[Them][PAWN] + & ei.attackedBy[Us][ALL_PIECES]; + + // Add a bonus according if the attacking pieces are minor or major + if (weakEnemies) + { + b = weakEnemies & (ei.attackedBy[Us][KNIGHT] | ei.attackedBy[Us][BISHOP]); + if (b) + score += Threat[0][type_of(pos.piece_on(lsb(b)))]; + + b = weakEnemies & (ei.attackedBy[Us][ROOK] | ei.attackedBy[Us][QUEEN]); 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]); + score += Threat[1][type_of(pos.piece_on(lsb(b)))]; + + b = weakEnemies & ~ei.attackedBy[Them][ALL_PIECES]; + if (b) + score += more_than_one(b) ? Hanging * popcount(b) : Hanging; } + + if (Trace) + Tracing::terms[Us][Tracing::THREAT] = score; + + return score; } - // evaluate_passed_pawns<>() evaluates the passed pawns of the given color + // evaluate_passed_pawns() evaluates the passed pawns of the given color - template - void evaluate_passed_pawns(const Position& pos, EvalInfo& ei) { + template + Score evaluate_passed_pawns(const Position& pos, const EvalInfo& ei) { const Color Them = (Us == WHITE ? BLACK : WHITE); - Bitboard squaresToQueen, defendedSquares, unsafeSquares, supportingPawns; - Bitboard b = ei.pi->passed_pawns() & pos.pieces_of_color(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.pawn_is_passed(Us, s)); + assert(pos.pawn_passed(Us, s)); - int r = int(relative_rank(Us, s) - RANK_2); - int tr = 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)); - if (tr) + if (rr) { Square blockSq = s + pawn_push(Us); - // 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); + // Adjust bonus based on the king's proximity + ebonus += square_distance(pos.king_square(Them), blockSq) * 5 * rr + - square_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 -= square_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)) { - squaresToQueen = squares_in_front_of(Us, s); - defendedSquares = squaresToQueen & ei.attacked_by(Us); + squaresToQueen = forward_bb(Us, s); // 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))) + if ( unlikely(forward_bb(Them, s) & pos.pieces(Them, ROOK, QUEEN)) + && (forward_bb(Them, s) & pos.pieces(Them, ROOK, QUEEN) & pos.attacks_from(s))) unsafeSquares = squaresToQueen; else - unsafeSquares = squaresToQueen & (ei.attacked_by(Them) | pos.pieces_of_color(Them)); + unsafeSquares = squaresToQueen & (ei.attackedBy[Them][ALL_PIECES] | pos.pieces(Them)); - // 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)); + if ( unlikely(forward_bb(Them, s) & pos.pieces(Us, ROOK, QUEEN)) + && (forward_bb(Them, s) & pos.pieces(Us, ROOK, QUEEN) & pos.attacks_from(s))) + defendedSquares = squaresToQueen; 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; - } + defendedSquares = squaresToQueen & ei.attackedBy[Us][ALL_PIECES]; - // 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]); - - } // while - } + // 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; - // 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. + else if (defendedSquares & blockSq) + k += 4; - void evaluate_trapped_bishop_a7h7(const Position& pos, Square s, Color us, EvalInfo &ei) { - - assert(square_is_ok(s)); - assert(pos.piece_on(s) == piece_of_color_and_type(us, BISHOP)); + mbonus += k * rr, ebonus += k * rr; + } + else if(pos.pieces(Us) & blockSq) + mbonus += rr * 3 + r * 2 + 3, ebonus += rr + r * 2; + } // rr != 0 - 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); + if (pos.count(Us) < pos.count(Them)) + ebonus += ebonus / 4; - if ( pos.piece_on(b6) == piece_of_color_and_type(opposite_color(us), PAWN) - && pos.see(s, b6) < 0 - && pos.see(s, b8) < 0) - { - ei.value -= Sign[us] * TrappedBishopA7H7Penalty; + score += make_score(mbonus, ebonus); } - } - - // 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. + if (Trace) + Tracing::terms[Us][Tracing::PASSED] = apply_weight(score, Weights[PassedPawns]); - void evaluate_trapped_bishop_a1h1(const Position& pos, Square s, Color us, EvalInfo& ei) { - - Piece pawn = piece_of_color_and_type(us, PAWN); - Square b2, b3, c3; + // Add the scores to the middlegame and endgame eval + return apply_weight(score, Weights[PassedPawns]); + } - assert(Chess960); - assert(square_is_ok(s)); - assert(pos.piece_on(s) == piece_of_color_and_type(us, BISHOP)); - 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_unstoppable_pawns() scores the most advanced among the passed and + // candidate pawns. In case both players have no pieces but pawns, this is + // somewhat related to the possibility that pawns are unstoppable. - if (pos.piece_on(b2) == pawn) - { - Score penalty; + Score evaluate_unstoppable_pawns(Color us, const EvalInfo& ei) { - if (!pos.square_is_empty(b3)) - penalty = 2 * TrappedBishopA1H1Penalty; - else if (pos.piece_on(c3) == pawn) - penalty = TrappedBishopA1H1Penalty; - else - penalty = TrappedBishopA1H1Penalty / 2; + Bitboard b = ei.pi->passed_pawns(us) | ei.pi->candidate_pawns(us); - ei.value -= Sign[us] * penalty; - } + return b ? Unstoppable * int(relative_rank(us, frontmost_sq(us, b))) : SCORE_ZERO; } @@ -934,89 +640,261 @@ namespace { // 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 - int evaluate_space(const Position& pos, EvalInfo& ei) { + // material hash table. The aim is to improve play on game opening. + template + int evaluate_space(const Position& pos, const 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 + // 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(PAWN, Us) - & ~ei.attacked_by(Them, PAWN) - & (ei.attacked_by(Us) | ~ei.attacked_by(Them)); + & ~pos.pieces(Us, PAWN) + & ~ei.attackedBy[Them][PAWN] + & (ei.attackedBy[Us][ALL_PIECES] | ~ei.attackedBy[Them][ALL_PIECES]); // Find all squares which are at most three squares behind some friendly pawn - Bitboard behind = pos.pieces(PAWN, Us); + Bitboard behind = pos.pieces(Us, PAWN); behind |= (Us == WHITE ? behind >> 8 : behind << 8); behind |= (Us == WHITE ? behind >> 16 : behind << 16); - return count_1s_max_15(safe) + count_1s_max_15(behind & safe); + // Since SpaceMask[Us] is fully on our half of the board + assert(unsigned(safe >> (Us == WHITE ? 32 : 0)) == 0); + + // Count safe + (behind & safe) with a single popcount + return popcount((Us == WHITE ? safe << 32 : safe >> 32) | (behind & safe)); + } + + + // do_evaluate() is the evaluation entry point, called directly from evaluate() + + template + Value do_evaluate(const Position& pos) { + + assert(!pos.checkers()); + + EvalInfo ei; + Score score, mobility[2] = { SCORE_ZERO, SCORE_ZERO }; + Thread* thisThread = pos.this_thread(); + + // 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(); + + // Probe the material hash table + ei.mi = Material::probe(pos, thisThread->materialTable, thisThread->endgames); + score += 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); + + // Probe the pawn hash table + ei.pi = Pawns::probe(pos, thisThread->pawnsTable); + score += apply_weight(ei.pi->pawns_value(), Weights[PawnStructure]); + + // Initialize attack and king safety bitboards + init_eval_info(pos, ei); + init_eval_info(pos, ei); + + ei.attackedBy[WHITE][ALL_PIECES] |= ei.attackedBy[WHITE][KING]; + ei.attackedBy[BLACK][ALL_PIECES] |= ei.attackedBy[BLACK][KING]; + + // Do not include in mobility squares protected by enemy pawns or occupied by our pawns or king + Bitboard mobilityArea[] = { ~(ei.attackedBy[BLACK][PAWN] | pos.pieces(WHITE, PAWN, KING)), + ~(ei.attackedBy[WHITE][PAWN] | pos.pieces(BLACK, PAWN, KING)) }; + + // Evaluate pieces and mobility + score += evaluate_pieces(pos, ei, mobility, mobilityArea); + score += apply_weight(mobility[WHITE] - mobility[BLACK], Weights[Mobility]); + + // 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); + + // Evaluate tactical threats, we need full attack information including king + score += evaluate_threats(pos, ei) + - evaluate_threats(pos, ei); + + // 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)) + score += evaluate_unstoppable_pawns(WHITE, ei) + - evaluate_unstoppable_pawns(BLACK, ei); + + // Evaluate space for both sides, only in middlegame + if (ei.mi->space_weight()) + { + int s = evaluate_space(pos, ei) - evaluate_space(pos, ei); + score += apply_weight(s * ei.mi->space_weight(), Weights[Space]); + } + + // 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); + + // 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()) { + // Ignoring any pawns, do both sides only have a single bishop and no + // other pieces? + if ( pos.non_pawn_material(WHITE) == BishopValueMg + && pos.non_pawn_material(BLACK) == BishopValueMg) + { + // 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.count(WHITE) + pos.count(BLACK) == 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 * sf / SCALE_FACTOR_NORMAL); + } else if ( abs(eg_value(score)) <= BishopValueEg + && ei.pi->pawn_span(strongSide) <= 1 + && !pos.pawn_passed(~strongSide, pos.king_square(~strongSide))) { + // Endings where weaker side can be place his king in front of the opponent's pawns are drawish. + sf = ScaleFactor(ScalePawnSpan[ei.pi->pawn_span(strongSide)]); + } + } + + // 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; + + v /= int(PHASE_MIDGAME); + + // In case of tracing add all single evaluation contributions for both white and black + if (Trace) + { + Tracing::add_term(Tracing::MATERIAL, pos.psq_score()); + Tracing::add_term(Tracing::IMBALANCE, ei.mi->material_value()); + Tracing::add_term(PAWN, ei.pi->pawns_value()); + Tracing::add_term(Tracing::MOBILITY, apply_weight(mobility[WHITE], Weights[Mobility]) + , apply_weight(mobility[BLACK], Weights[Mobility])); + Score w = ei.mi->space_weight() * evaluate_space(pos, ei); + Score b = ei.mi->space_weight() * evaluate_space(pos, ei); + Tracing::add_term(Tracing::SPACE, apply_weight(w, Weights[Space]), apply_weight(b, Weights[Space])); + Tracing::add_term(Tracing::TOTAL, score); + Tracing::ei = ei; + Tracing::sf = sf; + } + + return pos.side_to_move() == WHITE ? v : -v; } - // apply_weight() applies an evaluation weight to a value trying to prevent overflow + // Tracing function definitions + + double Tracing::to_cp(Value v) { return double(v) / PawnValueEg; } + + void Tracing::add_term(int idx, Score wScore, Score bScore) { + + terms[WHITE][idx] = wScore; + terms[BLACK][idx] = bScore; + } - 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); + void Tracing::format_row(std::stringstream& ss, const char* name, int idx) { + + Score wScore = terms[WHITE][idx]; + Score bScore = terms[BLACK][idx]; + + switch (idx) { + case MATERIAL: case IMBALANCE: case PAWN: case TOTAL: + ss << std::setw(15) << name << " | --- --- | --- --- | " + << std::setw(5) << to_cp(mg_value(wScore - bScore)) << " " + << std::setw(5) << to_cp(eg_value(wScore - bScore)) << " \n"; + break; + default: + ss << std::setw(15) << name << " | " << std::noshowpos + << std::setw(5) << to_cp(mg_value(wScore)) << " " + << std::setw(5) << to_cp(eg_value(wScore)) << " | " + << std::setw(5) << to_cp(mg_value(bScore)) << " " + << std::setw(5) << to_cp(eg_value(bScore)) << " | " + << std::setw(5) << to_cp(mg_value(wScore - bScore)) << " " + << std::setw(5) << to_cp(eg_value(wScore - bScore)) << " \n"; + } } + std::string Tracing::do_trace(const Position& pos) { + + std::memset(terms, 0, sizeof(terms)); + + Value v = do_evaluate(pos); + v = pos.side_to_move() == WHITE ? v : -v; // White's point of view - // 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. + 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"; - Value scale_by_game_phase(const Score& v, Phase ph, const ScaleFactor sf[]) { + format_row(ss, "Material", MATERIAL); + format_row(ss, "Imbalance", IMBALANCE); + format_row(ss, "Pawns", PAWN); + format_row(ss, "Knights", KNIGHT); + format_row(ss, "Bishops", BISHOP); + format_row(ss, "Rooks", ROOK); + format_row(ss, "Queens", QUEEN); + format_row(ss, "Mobility", MOBILITY); + format_row(ss, "King safety", KING); + format_row(ss, "Threats", THREAT); + format_row(ss, "Passed pawns", PASSED); + format_row(ss, "Space", SPACE); - 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); + ss << "----------------+-------------+-------------+-------------\n"; + format_row(ss, "Total", TOTAL); - Value eg = eg_value(v); - ScaleFactor f = sf[eg > VALUE_ZERO ? WHITE : BLACK]; - Value ev = Value((eg * int(f)) / SCALE_FACTOR_NORMAL); + ss << "\nTotal Evaluation: " << to_cp(v) << " (white side)\n"; - int result = (mg_value(v) * int(ph) + ev * int(128 - ph)) / 128; - return Value(result & ~(GrainSize - 1)); + return ss.str(); } +} // namespace - // weight_option() computes the value of an evaluation weight, by combining - // two UCI-configurable weights (midgame and endgame) with an internal weight. - Score weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight) { +namespace Eval { - // 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; + /// 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. - return apply_weight(make_score(mg, eg), internalWeight); + Value evaluate(const Position& pos) { + return do_evaluate(pos) + Tempo; } - // init_safety() initizes the king safety evaluation, based on UCI - // parameters. It is called from read_weights(). - void init_safety() { + /// 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); + } - 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++) - { - t[i] = Value(int(0.4 * i * i)); + /// init() computes evaluation weights from the corresponding UCI parameters + /// and setup king tables. - if (i > 0) - t[i] = Min(t[i], t[i - 1] + MaxSlope); + void init() { - t[i] = Min(t[i], Peak); - } + const double MaxSlope = 30; + const double Peak = 1280; - // 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]); + for (int t = 0, i = 1; i < 100; ++i) + { + t = int(std::min(Peak, std::min(0.4 * i * i, t + MaxSlope))); + KingDanger[i] = apply_weight(make_score(t, 0), Weights[KingSafety]); + } } -} + +} // namespace Eval