X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;ds=sidebyside;f=src%2Fevaluate.cpp;h=9c83eb6fe3caf2f3702800fe8e9270271612d320;hb=69240a982d8c3a2d01fab04c284be43853ab2bc9;hp=73ffcfb053057a6a203674dff264702940f55110;hpb=a98dee783582c84ca2647ca28daad0c9a13d1d35;p=stockfish diff --git a/src/evaluate.cpp b/src/evaluate.cpp index 73ffcfb0..9c83eb6f 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) 2008-2015 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 @@ -17,1015 +17,632 @@ 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 "thread.h" -#include "ucioption.h" - - -//// -//// Local definitions -//// namespace { - const int Sign[2] = { 1, -1 }; + namespace Trace { - // Evaluation grain size, must be a power of 2 - const int GrainSize = 8; + enum Term { // First 8 entries are for PieceType + MATERIAL = 8, IMBALANCE, MOBILITY, THREAT, PASSED, SPACE, TOTAL, TERM_NB + }; - // Evaluation weights, initialized from UCI options - enum { Mobility, PawnStructure, PassedPawns, Space, KingDangerUs, KingDangerThem }; - Score Weights[6]; + double scores[TERM_NB][COLOR_NB][PHASE_NB]; - typedef Value V; - #define S(mg, eg) make_score(mg, eg) + double to_cp(Value v) { return double(v) / PawnValueEg; } - // 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) - }; - - // 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) - }; + void add(int idx, Color c, Score s) { + scores[idx][c][MG] = to_cp(mg_value(s)); + scores[idx][c][EG] = to_cp(eg_value(s)); + } - // 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) - }; + void add(int idx, Score w, Score b = SCORE_ZERO) { + add(idx, WHITE, w); add(idx, BLACK, b); + } - // 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) - }; + std::ostream& operator<<(std::ostream& os, Term t) { - // 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) - }; + if (t == MATERIAL || t == IMBALANCE || t == Term(PAWN) || t == TOTAL) + os << " --- --- | --- --- | "; + else + os << std::setw(5) << scores[t][WHITE][MG] << " " + << std::setw(5) << scores[t][WHITE][EG] << " | " + << std::setw(5) << scores[t][BLACK][MG] << " " + << std::setw(5) << scores[t][BLACK][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 - }; + os << std::setw(5) << scores[t][WHITE][MG] - scores[t][BLACK][MG] << " " + << std::setw(5) << scores[t][WHITE][EG] - scores[t][BLACK][EG] << " \n"; - 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 - }; + return os; + } + } - // 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 + using namespace Trace; + + // Struct EvalInfo contains various information computed and collected + // by the evaluation functions. + struct EvalInfo { + + // attackedBy[color][piece type] is a bitboard representing all squares + // attacked by a given color and piece type (can be also ALL_PIECES). + 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]; + Material::Entry* me; + Pawns::Entry* pi; }; - // ThreatedByPawnPenalty[] contains a penalty according to which piece - // type is attacked by an enemy pawn. - const Score ThreatedByPawnPenalty[8] = { - S(0, 0), S(0, 0), S(56, 70), S(56, 70), S(76, 99), S(86, 118) - }; - #undef S + // Evaluation weights, indexed by the corresponding evaluation term + enum { Mobility, PawnStructure, PassedPawns, Space, KingSafety, Threats }; - // Bonus for unstoppable passed pawns - const Value UnstoppablePawnValue = Value(0x500); + const struct Weight { int mg, eg; } Weights[] = { + {266, 334}, {214, 203}, {193, 262}, {47, 0}, {330, 0}, {404, 241} + }; - // 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); + Score operator*(Score s, const Weight& w) { + return make_score(mg_value(s) * w.mg / 256, eg_value(s) * w.eg / 256); + } - // 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); + #define V(v) Value(v) + #define S(mg, eg) make_score(mg, eg) - // Penalty for a bishop on a7/h7 (a2/h2 for black) which is trapped by - // enemy pawns. - const Score TrappedBishopA7H7Penalty = make_score(300, 300); + // 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(-70,-52), S(-52,-37), S( -7,-17), S( 0, -6), S( 8, 5), S( 16, 9), // Knights + S( 23, 20), S( 31, 21), S( 36, 22) }, + { S(-49,-44), S(-22,-13), S( 16, 0), S( 27, 11), S( 38, 19), S( 52, 34), // Bishops + S( 56, 44), S( 65, 47), S( 67, 51), S( 73, 56), S( 81, 59), S( 83, 69), + S( 95, 72), S(100, 75) }, + { S(-49,-57), S(-22,-14), S(-10, 18), S( -5, 39), S( -4, 50), S( -2, 58), // Rooks + S( 6, 78), S( 11, 86), S( 17, 92), S( 19,103), S( 26,111), S( 27,115), + S( 36,119), S( 41,121), S( 50,122) }, + { S(-41,-24), S(-26, -8), S( 0, 6), S( 2, 14), S( 12, 27), S( 21, 40), // Queens + S( 22, 45), S( 37, 55), S( 40, 57), S( 43, 63), S( 50, 68), S( 52, 74), + S( 56, 80), S( 66, 84), S( 68, 85), S( 69, 88), S( 71, 92), S( 72, 94), + S( 80, 96), S( 89, 98), S( 94,101), S(102,113), S(106,114), S(107,116), + S(112,125), S(113,127), S(117,137), S(122,143) } + }; - // 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)) + // 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(42,11), S(63,17) }, // Knights + { S(18, 5), S(27, 8) } // Bishops }; - // 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); + // ReachableOutpost[knight/bishop][supported by pawn] contains bonuses for + // knights and bishops which can reach an outpost square in one move, bigger + // if outpost square is supported by a pawn. + const Score ReachableOutpost[][2] = { + { S(21, 5), S(31, 8) }, // Knights + { S( 8, 2), S(13, 4) } // Bishops + }; - // 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)) + // Threat[minor/rook][attacked PieceType] contains + // bonuses according to which piece type attacks which one. + // Attacks on lesser pieces which are pawn defended are not considered. + const Score Threat[2][PIECE_TYPE_NB] = { + { S(0, 0), S(0, 32), S(25, 39), S(28, 44), S(42, 98), S(35,105) }, // Minor attacks + { S(0, 0), S(0, 27), S(26, 57), S(26, 57), S( 0, 30), S(23, 51) } // Rook attacks }; - // The SpaceMask[color] contains the area of the board which is considered - // by the space evaluation. In the middle game, each side is given a bonus - // based on how many squares inside this area are safe and available for - // friendly minor pieces. - const Bitboard SpaceMask[2] = { - (1ULL< - Value do_evaluate(const Position& pos, EvalInfo& ei); + #undef S + #undef V - template - void init_attack_tables(const Position& pos, EvalInfo& ei); + // King danger constants and variables. The king danger scores are looked-up + // in KingDanger[]. Various little "meta-bonuses" measuring the strength + // of the enemy attack are added up into an integer, which is used as an + // index to KingDanger[]. + Score KingDanger[512]; - template - void evaluate_pieces_of_color(const Position& pos, EvalInfo& ei); + // KingAttackWeights[PieceType] contains king attack weights by piece type + const int KingAttackWeights[PIECE_TYPE_NB] = { 0, 0, 7, 5, 4, 1 }; - template - void evaluate_king(const Position& pos, EvalInfo& ei); + // Penalties for enemy's safe checks + const int QueenContactCheck = 89; + const int QueenCheck = 50; + const int RookCheck = 45; + const int BishopCheck = 6; + const int KnightCheck = 14; - template - void evaluate_threats(const Position& pos, EvalInfo& ei); - template - int evaluate_space(const Position& pos, EvalInfo& ei); + // eval_init() initializes king and attack bitboards for given color + // adding pawn attacks. To be done at the beginning of the evaluation. template - void evaluate_passed_pawns(const Position& pos, EvalInfo& ei); - - void evaluate_unstoppable_pawns(const Position& pos, EvalInfo& ei); - void evaluate_trapped_bishop_a7h7(const Position& pos, Square s, Color us, EvalInfo& ei); - void evaluate_trapped_bishop_a1h1(const Position& pos, Square s, Color us, EvalInfo& ei); - inline 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); - - // If one side has only a king, check whether exsists any unstoppable passed pawn - if (!pos.non_pawn_material(WHITE) || !pos.non_pawn_material(BLACK)) - evaluate_unstoppable_pawns(pos, ei); - - Phase phase = 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) + void eval_init(const Position& pos, EvalInfo& ei) { - ei.value += make_score(ei.pi->queenside_storm_value(WHITE) - ei.pi->kingside_storm_value(BLACK), 0); + const Color Them = (Us == WHITE ? BLACK : WHITE); + const Square Down = (Us == WHITE ? DELTA_S : DELTA_N); - else if ( square_file(pos.king_square(WHITE)) <= FILE_D - && square_file(pos.king_square(BLACK)) >= FILE_E) + ei.pinnedPieces[Us] = pos.pinned_pieces(Us); + Bitboard b = ei.attackedBy[Them][KING] = pos.attacks_from(pos.square(Them)); + ei.attackedBy[Them][ALL_PIECES] |= b; + ei.attackedBy[Us][ALL_PIECES] |= ei.attackedBy[Us][PAWN] = ei.pi->pawn_attacks(Us); - 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]); - } - } - - // 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(0)) - || (factor[BLACK] == SCALE_FACTOR_NORMAL && eg_value(ei.value) < 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 - return Sign[pos.side_to_move()] * scale_by_game_phase(ei.value, phase, factor); -} - -} // namespace - -/// init_eval() initializes various tables used by the evaluation function - -void init_eval(int threads) { - - assert(threads <= MAX_THREADS); - - 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.non_pawn_material(Us) >= QueenValueMg) { - 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; - } -} - - -/// 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. - - template - void init_attack_tables(const Position& pos, EvalInfo& ei) { - - 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; + else + ei.kingRing[Them] = ei.kingAttackersCount[Us] = 0; } - // evaluate_outposts() evaluates bishop and knight outposts squares + // evaluate_pieces() assigns bonuses and penalties to the pieces of a given + // color and type. - template - void evaluate_outposts(const Position& pos, EvalInfo& ei, Square s) { + template + Score evaluate_pieces(const Position& pos, EvalInfo& ei, Score* mobility, + const Bitboard* mobilityArea) { + Bitboard b, bb; + Square s; + Score score = SCORE_ZERO; + const PieceType NextPt = (Us == WHITE ? Pt : PieceType(Pt + 1)); const Color Them = (Us == WHITE ? BLACK : WHITE); + const Bitboard OutpostRanks = (Us == WHITE ? Rank4BB | Rank5BB | Rank6BB + : Rank5BB | Rank4BB | Rank3BB); + const Square* pl = pos.squares(Us); - // Initial bonus based on square - Value bonus = (Piece == BISHOP ? BishopOutpostBonus[relative_square(Us, s)] - : KnightOutpostBonus[relative_square(Us, s)]); + ei.attackedBy[Us][Pt] = 0; - // 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)) + while ((s = *pl++) != SQ_NONE) { - if ( pos.pieces(KNIGHT, Them) == EmptyBoardBB - && (SquaresByColorBB[square_color(s)] & pos.pieces(BISHOP, Them)) == EmptyBoardBB) - bonus += bonus + bonus / 2; - else - bonus += bonus / 2; - } - ei.value += Sign[Us] * make_score(bonus, bonus); - } - - - // evaluate_pieces<>() assigns bonuses and penalties to the pieces of a given color - - template - void evaluate_pieces(const Position& pos, EvalInfo& ei, Bitboard no_mob_area) { + // 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); - Bitboard b; - Square s, ksq; - int mob; - File f; + if (ei.pinnedPieces[Us] & s) + b &= LineBB[pos.square(Us)][s]; - const Color Them = (Us == WHITE ? BLACK : WHITE); - const Square* ptr = pos.piece_list_begin(Us, Piece); + ei.attackedBy[Us][ALL_PIECES] |= ei.attackedBy[Us][Pt] |= b; - while ((s = *ptr++) != 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); - - // Update attack info - ei.attackedBy[Us][Piece] |= b; - - // King attacks - if (b & ei.kingZone[Us]) + 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]; + 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]; + int mob = popcount(b & mobilityArea[Us]); - // Bishop and knight outposts squares - if ((Piece == BISHOP || Piece == KNIGHT) && pos.square_is_weak(s, Us)) - evaluate_outposts(pos, ei, s); + mobility[Us] += MobilityBonus[Pt][mob]; - // Special patterns: trapped bishops on a7/h7/a2/h2 - // and trapped bishops on a1/h1/a8/h8 in Chess960. - if (Piece == BISHOP) + if (Pt == BISHOP || Pt == KNIGHT) { - 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); - } + // Bonus for outpost squares + bb = OutpostRanks & ~ei.pi->pawn_attacks_span(Them); + if (bb & s) + score += Outpost[Pt == BISHOP][!!(ei.attackedBy[Us][PAWN] & s)]; + else + { + bb &= b & ~pos.pieces(Us); + if (bb) + score += ReachableOutpost[Pt == BISHOP][!!(ei.attackedBy[Us][PAWN] & bb)]; + } - // 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) - { - ei.value += Sign[Us] * (Piece == ROOK ? RookOn7thBonus : QueenOn7thBonus); + // 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; + } } - // 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)) + // Bonus for aligning with 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 alignedPawns = pos.pieces(Them, PAWN) & PseudoAttacks[ROOK][s]; + if (alignedPawns) + score += popcount(alignedPawns) * 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)) - continue; - - ksq = pos.king_square(Us); + // 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; - if ( square_file(ksq) >= FILE_E - && square_file(s) > square_file(ksq) - && (relative_rank(Us, ksq) == RANK_1 || square_rank(ksq) == square_rank(s))) + // Penalize when trapped by the king, even more if king cannot castle + if (mob <= 3 && !ei.pi->semiopen_file(Us, file_of(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); + Square ksq = pos.square(Us); + + 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)); } } } - } + if (DoTrace) + Trace::add(Pt, Us, score); - // evaluate_threats<>() assigns bonuses according to the type of attacking piece - // and the type of attacked one. - - template - void evaluate_threats(const Position& pos, EvalInfo& ei) { - - const Color Them = (Us == WHITE ? BLACK : WHITE); - - Bitboard b; - Score bonus = make_score(0, 0); - - // Enemy pieces not defended by a pawn and under our attack - Bitboard weakEnemies = pos.pieces_of_color(Them) - & ~ei.attackedBy[Them][PAWN] - & ei.attackedBy[Us][0]; - if (!weakEnemies) - return; - - // Add bonus according to type of attacked enemy pieces and to the - // type of attacking piece, from knights to queens. Kings are not - // considered because are already special handled in king evaluation. - for (PieceType pt1 = KNIGHT; pt1 < KING; pt1++) - { - b = ei.attackedBy[Us][pt1] & weakEnemies; - if (b) - for (PieceType pt2 = PAWN; pt2 < KING; pt2++) - if (b & pos.pieces(pt2)) - bonus += ThreatBonus[pt1][pt2]; - } - ei.value += Sign[Us] * bonus; + // Recursively call evaluate_pieces() of next piece type until KING excluded + return score - evaluate_pieces(pos, ei, mobility, mobilityArea); } + template<> + Score evaluate_pieces(const Position&, EvalInfo&, Score*, const Bitboard*) { return SCORE_ZERO; } + template<> + Score evaluate_pieces< true, WHITE, KING>(const Position&, EvalInfo&, Score*, const Bitboard*) { return SCORE_ZERO; } - // evaluate_pieces_of_color<>() assigns bonuses and penalties to all the - // pieces of a given color. - - template - void evaluate_pieces_of_color(const Position& pos, EvalInfo& ei) { - - 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]; - } + // 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; - const Square ksq = pos.king_square(Us); + int attackUnits; + const Square ksq = pos.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 - // 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)); + // 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 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 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(72, ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) + + 9 * ei.kingAdjacentZoneAttacksCount[Them] + + 27 * popcount(undefended) + + 11 * !!ei.pinnedPieces[Us] + - 64 * !pos.count(Them) + - mg_value(score) / 8; + + // 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) { - // ...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] + | ei.attackedBy[Them][KING]; + 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 distance checks for sliders and knights + safe = ~(ei.attackedBy[Us][ALL_PIECES] | pos.pieces(Them)); - b1 = pos.attacks_from(ksq) & safe; + 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); + score -= Checked; + } // 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); + score -= Checked; + } // 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); + score -= Checked; + } // 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 += 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]); + { + attackUnits += KnightCheck * popcount(b); + score -= Checked; + } + + // 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)]; } + + if (DoTrace) + Trace::add(KING, Us, score); + + return score; } - // evaluate_passed_pawns<>() evaluates the passed pawns of the given color + // evaluate_threats() assigns bonuses according to the type of attacking piece + // and the type of attacked one. - template - void evaluate_passed_pawns(const Position& pos, EvalInfo& ei) { + template + Score evaluate_threats(const Position& pos, const EvalInfo& ei) { - const Color Them = (Us == WHITE ? BLACK : WHITE); + 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); - Bitboard squaresToQueen, defendedSquares, unsafeSquares, supportingPawns; - Bitboard b = ei.pi->passed_pawns() & pos.pieces_of_color(Us); + enum { Minor, Rook }; - while (b) + Bitboard b, weak, defended, safeThreats; + Score score = SCORE_ZERO; + + // Non-pawn enemies attacked by a pawn + weak = (pos.pieces(Them) ^ pos.pieces(Them, PAWN)) & ei.attackedBy[Us][PAWN]; + + if (weak) { - Square s = pop_1st_bit(&b); + b = pos.pieces(Us, PAWN) & ( ~ei.attackedBy[Them][ALL_PIECES] + | ei.attackedBy[Us][ALL_PIECES]); - assert(pos.pawn_is_passed(Us, s)); + safeThreats = (shift_bb(b) | shift_bb(b)) & weak; - int r = int(relative_rank(Us, s) - RANK_2); - int tr = r * (r - 1); + if (weak ^ safeThreats) + score += ThreatenedByHangingPawn; - // Base bonus based on rank - Value mbonus = Value(20 * tr); - Value ebonus = Value(10 + r * r * 10); + while (safeThreats) + score += ThreatenedByPawn[type_of(pos.piece_on(pop_lsb(&safeThreats)))]; + } - if (tr) - { - Square blockSq = s + pawn_push(Us); + // Non-pawn enemies defended by a pawn + defended = (pos.pieces(Them) ^ pos.pieces(Them, PAWN)) & ei.attackedBy[Them][PAWN]; - // 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); + // Enemies not defended by a pawn and under our attack + weak = pos.pieces(Them) + & ~ei.attackedBy[Them][PAWN] + & ei.attackedBy[Us][ALL_PIECES]; - // If the pawn is free to advance, increase bonus - if (pos.square_is_empty(blockSq)) - { - squaresToQueen = squares_in_front_of(Us, s); - defendedSquares = squaresToQueen & ei.attacked_by(Us); - - // If there is an enemy rook or queen attacking the pawn from behind, - // add all X-ray attacks by the rook or queen. Otherwise consider only - // the squares in the pawn's path attacked or occupied by the enemy. - if ( (squares_behind(Us, s) & pos.pieces(ROOK, QUEEN, Them)) - && (squares_behind(Us, s) & pos.pieces(ROOK, QUEEN, Them) & pos.attacks_from(s))) - unsafeSquares = squaresToQueen; - else - unsafeSquares = squaresToQueen & (ei.attacked_by(Them) | pos.pieces_of_color(Them)); - - // If there aren't enemy attacks or pieces along the path to queen give - // huge bonus. Even bigger if we protect the pawn's path. - if (!unsafeSquares) - ebonus += Value(tr * (squaresToQueen == defendedSquares ? 17 : 15)); - else - // OK, there are enemy attacks or pieces (but not pawns). Are those - // squares which are attacked by the enemy also attacked by us ? - // If yes, big bonus (but smaller than when there are no enemy attacks), - // if no, somewhat smaller bonus. - ebonus += Value(tr * ((unsafeSquares & defendedSquares) == unsafeSquares ? 13 : 8)); - - // At last, add a small bonus when there are no *friendly* pieces - // in the pawn's path. - if (!(squaresToQueen & pos.pieces_of_color(Us))) - ebonus += Value(tr); - } - } // tr != 0 - - // Increase the bonus if the passed pawn is supported by a friendly pawn - // on the same rank and a bit smaller if it's on the previous rank. - supportingPawns = pos.pieces(PAWN, Us) & neighboring_files_bb(s); - if (supportingPawns & rank_bb(s)) - ebonus += Value(r * 20); - else if (supportingPawns & rank_bb(s - pawn_push(Us))) - ebonus += Value(r * 12); - - // Rook pawns are a special case: They are sometimes worse, and - // sometimes better than other passed pawns. It is difficult to find - // good rules for determining whether they are good or bad. For now, - // we try the following: Increase the value for rook pawns if the - // other side has no pieces apart from a knight, and decrease the - // value if the other side has a rook or queen. - if (square_file(s) == FILE_A || square_file(s) == FILE_H) - { - if (pos.non_pawn_material(Them) <= KnightValueMidgame) - ebonus += ebonus / 4; - else if (pos.pieces(ROOK, QUEEN, Them)) - ebonus -= ebonus / 4; - } + // Add a bonus according to the kind of attacking pieces + if (defended | weak) + { + b = (defended | weak) & (ei.attackedBy[Us][KNIGHT] | ei.attackedBy[Us][BISHOP]); + while (b) + score += Threat[Minor][type_of(pos.piece_on(pop_lsb(&b)))]; - // 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]); + b = (pos.pieces(Them, QUEEN) | weak) & ei.attackedBy[Us][ROOK]; + while (b) + score += Threat[Rook ][type_of(pos.piece_on(pop_lsb(&b)))]; - } // while - } + b = weak & ~ei.attackedBy[Them][ALL_PIECES]; + if (b) + score += Hanging * popcount(b); + b = weak & ei.attackedBy[Us][KING]; + if (b) + score += more_than_one(b) ? KingOnMany : KingOnOne; + } - // evaluate_unstoppable_pawns() evaluates the unstoppable passed pawns for both sides + // Bonus if some pawns can safely push and attack an enemy piece + b = pos.pieces(Us, PAWN) & ~TRank7BB; + b = shift_bb(b | (shift_bb(b & TRank2BB) & ~pos.pieces())); - void evaluate_unstoppable_pawns(const Position& pos, EvalInfo& ei) { + b &= ~pos.pieces() + & ~ei.attackedBy[Them][PAWN] + & (ei.attackedBy[Us][ALL_PIECES] | ~ei.attackedBy[Them][ALL_PIECES]); - int movesToGo[2] = {0, 0}; - Square pawnToGo[2] = {SQ_NONE, SQ_NONE}; + b = (shift_bb(b) | shift_bb(b)) + & pos.pieces(Them) + & ~ei.attackedBy[Us][PAWN]; - for (Color c = WHITE; c <= BLACK; c++) - { - // Skip evaluation if other side has non-pawn pieces - if (pos.non_pawn_material(opposite_color(c))) - continue; + if (b) + score += popcount(b) * PawnAttackThreat; - Bitboard b = ei.pi->passed_pawns() & pos.pieces_of_color(c); + if (DoTrace) + Trace::add(THREAT, Us, score * Weights[Threats]); - while (b) - { - Square s = pop_1st_bit(&b); - Square queeningSquare = relative_square(c, make_square(square_file(s), RANK_8)); - int d = square_distance(s, queeningSquare) - - int(relative_rank(c, s) == RANK_2) // Double pawn push - - square_distance(pos.king_square(opposite_color(c)), queeningSquare) - + int(c != pos.side_to_move()); + return score * Weights[Threats]; + } - // Do we protect the path to queening ? - bool pathDefended = (ei.attacked_by(c) & squares_in_front_of(c, s)) == squares_in_front_of(c, s); - if (d < 0 || pathDefended) - { - int mtg = RANK_8 - relative_rank(c, s); - int blockerCount = count_1s_max_15(squares_in_front_of(c, s) & pos.occupied_squares()); - mtg += blockerCount; - d += blockerCount; - if ((d < 0 || pathDefended) && (!movesToGo[c] || movesToGo[c] > mtg)) - { - movesToGo[c] = mtg; - pawnToGo[c] = s; - } - } - } - } + // evaluate_passed_pawns() evaluates the passed pawns of the given color - // Neither side has an unstoppable passed pawn? - if (!(movesToGo[WHITE] | movesToGo[BLACK])) - return; + template + Score evaluate_passed_pawns(const Position& pos, const EvalInfo& ei) { - // Does only one side have an unstoppable passed pawn? - if (!movesToGo[WHITE] || !movesToGo[BLACK]) - { - Color winnerSide = movesToGo[WHITE] ? WHITE : BLACK; - ei.value += make_score(0, Sign[winnerSide] * (UnstoppablePawnValue - Value(0x40 * movesToGo[winnerSide]))); - } - else - { // Both sides have unstoppable pawns! Try to find out who queens - // first. We begin by transforming 'movesToGo' to the number of - // plies until the pawn queens for both sides. - movesToGo[WHITE] *= 2; - movesToGo[BLACK] *= 2; - movesToGo[pos.side_to_move()]--; - - Color winnerSide = movesToGo[WHITE] < movesToGo[BLACK] ? WHITE : BLACK; - Color loserSide = opposite_color(winnerSide); - - // If one side queens at least three plies before the other, that side wins - if (movesToGo[winnerSide] <= movesToGo[loserSide] - 3) - ei.value += Sign[winnerSide] * make_score(0, UnstoppablePawnValue - Value(0x40 * (movesToGo[winnerSide]/2))); - - // If one side queens one ply before the other and checks the king or attacks - // the undefended opponent's queening square, that side wins. To avoid cases - // where the opponent's king could move somewhere before first pawn queens we - // consider only free paths to queen for both pawns. - else if ( !(squares_in_front_of(WHITE, pawnToGo[WHITE]) & pos.occupied_squares()) - && !(squares_in_front_of(BLACK, pawnToGo[BLACK]) & pos.occupied_squares())) - { - assert(movesToGo[loserSide] - movesToGo[winnerSide] == 1); + const Color Them = (Us == WHITE ? BLACK : WHITE); - Square winnerQSq = relative_square(winnerSide, make_square(square_file(pawnToGo[winnerSide]), RANK_8)); - Square loserQSq = relative_square(loserSide, make_square(square_file(pawnToGo[loserSide]), RANK_8)); + Bitboard b, squaresToQueen, defendedSquares, unsafeSquares; + Score score = SCORE_ZERO; - Bitboard b = pos.occupied_squares(); - clear_bit(&b, pawnToGo[winnerSide]); - clear_bit(&b, pawnToGo[loserSide]); - b = queen_attacks_bb(winnerQSq, b); + b = ei.pi->passed_pawns(Us); - if ( (b & pos.pieces(KING, loserSide)) - ||(bit_is_set(b, loserQSq) && !bit_is_set(ei.attacked_by(loserSide), loserQSq))) - ei.value += Sign[winnerSide] * make_score(0, UnstoppablePawnValue - Value(0x40 * (movesToGo[winnerSide]/2))); - } - } - } + while (b) + { + Square s = pop_lsb(&b); + assert(pos.pawn_passed(Us, s)); - // 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. + int r = relative_rank(Us, s) - RANK_2; + int rr = r * (r - 1); - void evaluate_trapped_bishop_a7h7(const Position& pos, Square s, Color us, EvalInfo &ei) { + Value mbonus = Passed[MG][r], ebonus = Passed[EG][r]; - assert(square_is_ok(s)); - assert(pos.piece_on(s) == piece_of_color_and_type(us, BISHOP)); + if (rr) + { + Square blockSq = s + pawn_push(Us); - 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); + // Adjust bonus based on the king's proximity + ebonus += distance(pos.square(Them), blockSq) * 5 * rr + - distance(pos.square(Us ), blockSq) * 2 * rr; - 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; - } - } + // If blockSq is not the queening square then consider also a second push + if (relative_rank(Us, blockSq) != RANK_8) + ebonus -= distance(pos.square(Us), blockSq + pawn_push(Us)) * rr; + // If the pawn is free to advance, then increase the bonus + if (pos.empty(blockSq)) + { + // 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); - // 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. + Bitboard bb = forward_bb(Them, s) & pos.pieces(ROOK, QUEEN) & pos.attacks_from(s); - void evaluate_trapped_bishop_a1h1(const Position& pos, Square s, Color us, EvalInfo& ei) { + if (!(pos.pieces(Us) & bb)) + defendedSquares &= ei.attackedBy[Us][ALL_PIECES]; - Piece pawn = piece_of_color_and_type(us, PAWN); - Square b2, b3, c3; + if (!(pos.pieces(Them) & bb)) + unsafeSquares &= ei.attackedBy[Them][ALL_PIECES] | pos.pieces(Them); - assert(Chess960); - assert(square_is_ok(s)); - assert(pos.piece_on(s) == piece_of_color_and_type(us, BISHOP)); + // 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 ? 18 : !(unsafeSquares & blockSq) ? 8 : 0; - 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); - } + // 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; - if (pos.piece_on(b2) == pawn) - { - Score penalty; + 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 - if (!pos.square_is_empty(b3)) - penalty = 2 * TrappedBishopA1H1Penalty; - else if (pos.piece_on(c3) == pawn) - penalty = TrappedBishopA1H1Penalty; - else - penalty = TrappedBishopA1H1Penalty / 2; + if (pos.count(Us) < pos.count(Them)) + ebonus += ebonus / 4; - ei.value -= Sign[us] * penalty; + score += make_score(mbonus, ebonus) + PassedFile[file_of(s)]; } + + if (DoTrace) + Trace::add(PASSED, Us, score * Weights[PassedPawns]); + + // Add the scores to the middlegame and endgame eval + return score * Weights[PassedPawns]; } @@ -1033,91 +650,260 @@ namespace { // 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 - int evaluate_space(const Position& pos, EvalInfo& ei) { + // 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) { const Color Them = (Us == WHITE ? BLACK : WHITE); + const Bitboard SpaceMask = + Us == WHITE ? (FileCBB | FileDBB | FileEBB | FileFBB) & (Rank2BB | Rank3BB | Rank4BB) + : (FileCBB | FileDBB | FileEBB | FileFBB) & (Rank7BB | Rank6BB | Rank5BB); // 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)); + Bitboard safe = SpaceMask + & ~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 + 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); + + return make_score(bonus * weight * weight, 0); } - // apply_weight() applies an evaluation weight to a value trying to prevent overflow + // evaluate_initiative() computes the initiative correction value for the + // position, i.e. second order bonus/malus based on the known attacking/defending + // status of the players. + Score evaluate_initiative(const Position& pos, int asymmetry, Value eg) { + + int kingDistance = distance(pos.square(WHITE), pos.square(BLACK)); + int pawns = pos.count(WHITE) + pos.count(BLACK); + + // Compute the initiative bonus for the attacking side + int initiative = 8 * (pawns + asymmetry + kingDistance - 15); - 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); + // Now apply the bonus: note that we find the attacking side by extracting + // the sign of the endgame value, and that we carefully cap the bonus so + // that the endgame score will never be divided by more than two. + int value = ((eg > 0) - (eg < 0)) * std::max(initiative, -abs(eg / 2)); + + return make_score(0, value); } - // 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. + // evaluate_scale_factor() computes the scale factor for the winning side + ScaleFactor evaluate_scale_factor(const Position& pos, const EvalInfo& ei, Score score) { - Value scale_by_game_phase(const Score& v, Phase ph, const ScaleFactor sf[]) { + Color strongSide = eg_value(score) > VALUE_DRAW ? WHITE : BLACK; + ScaleFactor sf = ei.me->scale_factor(pos, strongSide); - 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); + // 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.me->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(31) : ScaleFactor(9); + + // 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(46 * 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.square(~strongSide))) + sf = ei.pi->pawn_span(strongSide) ? ScaleFactor(51) : ScaleFactor(37); + } + + return sf; + } + +} // namespace + + +/// evaluate() is the main evaluation function. It returns a static evaluation +/// of the position from the point of view of the side to move. + +template +Value Eval::evaluate(const Position& pos) { + + assert(!pos.checkers()); + + EvalInfo ei; + Score score, mobility[2] = { SCORE_ZERO, SCORE_ZERO }; + + // Initialize score by reading the incrementally updated scores included in + // the position object (material + piece square tables). Score is computed + // internally from the white point of view. + score = pos.psq_score(); + + // Probe the material hash table + ei.me = Material::probe(pos); + score += ei.me->imbalance(); + + // If we have a specialized evaluation function for the current material + // configuration, call it and return. + if (ei.me->specialized_eval_exists()) + return ei.me->evaluate(pos); + + // Probe the pawn hash table + ei.pi = Pawns::probe(pos); + score += ei.pi->pawns_score() * Weights[PawnStructure]; + + // Initialize attack and king safety bitboards + ei.attackedBy[WHITE][ALL_PIECES] = ei.attackedBy[BLACK][ALL_PIECES] = 0; + eval_init(pos, ei); + eval_init(pos, ei); + + // 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) + }; + + // Do not include in mobility area squares protected by enemy pawns, or occupied + // by our blocked pawns or king. + Bitboard mobilityArea[] = { + ~(ei.attackedBy[BLACK][PAWN] | blockedPawns[WHITE] | pos.square(WHITE)), + ~(ei.attackedBy[WHITE][PAWN] | blockedPawns[BLACK] | pos.square(BLACK)) + }; + + // Evaluate all pieces but king and pawns + score += evaluate_pieces(pos, ei, mobility, mobilityArea); + score += (mobility[WHITE] - mobility[BLACK]) * Weights[Mobility]; + + // Evaluate kings after all other pieces because we need full 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); - Value eg = eg_value(v); - ScaleFactor f = sf[eg > Value(0) ? WHITE : BLACK]; - Value ev = Value((eg * f) / int(SCALE_FACTOR_NORMAL)); + // 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; - int result = (mg_value(v) * ph + ev * (128 - ph)) / 128; - return Value(result & ~(GrainSize - 1)); + if ((b = ei.pi->passed_pawns(BLACK)) != 0) + score -= int(relative_rank(BLACK, frontmost_sq(BLACK, b))) * Unstoppable; } + // Evaluate space for both sides, only during opening + if (pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) >= 12222) + score += ( evaluate_space(pos, ei) + - evaluate_space(pos, ei)) * Weights[Space]; + + // Evaluate position potential for the winning side + score += evaluate_initiative(pos, ei.pi->pawn_asymmetry(), eg_value(score)); - // weight_option() computes the value of an evaluation weight, by combining - // two UCI-configurable weights (midgame and endgame) with an internal weight. + // Evaluate scale factor for the winning side + ScaleFactor sf = evaluate_scale_factor(pos, ei, score); - Score weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight) { + // Interpolate between a middlegame and a (scaled by 'sf') endgame score + Value v = mg_value(score) * int(ei.me->game_phase()) + + eg_value(score) * int(PHASE_MIDGAME - ei.me->game_phase()) * sf / SCALE_FACTOR_NORMAL; - // 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; + v /= int(PHASE_MIDGAME); - return apply_weight(make_score(mg, eg), internalWeight); + // In case of tracing add all remaining individual evaluation terms + if (DoTrace) + { + Trace::add(MATERIAL, pos.psq_score()); + Trace::add(IMBALANCE, ei.me->imbalance()); + Trace::add(PAWN, ei.pi->pawns_score()); + Trace::add(MOBILITY, mobility[WHITE] * Weights[Mobility] + , mobility[BLACK] * Weights[Mobility]); + Trace::add(SPACE, evaluate_space(pos, ei) * Weights[Space] + , evaluate_space(pos, ei) * Weights[Space]); + Trace::add(TOTAL, score); } - // init_safety() initizes the king safety evaluation, based on UCI - // parameters. It is called from read_weights(). + return (pos.side_to_move() == WHITE ? v : -v) + Eval::Tempo; // Side to move point of view +} - void init_safety() { +// Explicit template instantiations +template Value Eval::evaluate(const Position&); +template Value Eval::evaluate(const Position&); + + +/// 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. Useful for debugging. + +std::string Eval::trace(const Position& pos) { + + std::memset(scores, 0, sizeof(scores)); + + Value v = 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(); +} - 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, usually at startup - if (i > 0) - t[i] = Min(t[i], t[i - 1] + MaxSlope); +void Eval::init() { - t[i] = Min(t[i], Peak); - } + const int MaxSlope = 8700; + const int Peak = 1280000; + int t = 0; - // 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 i = 0; i < 400; ++i) + { + t = std::min(Peak, std::min(i * i * 27, t + MaxSlope)); + KingDanger[i] = make_score(t / 1000, 0) * Weights[KingSafety]; } }