X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fevaluate.cpp;h=a5868f504b0b827af8e7320b780f57e6a2c2f656;hb=fdbe8006e058f3d2852117045be51b8841daa16f;hp=f4b7fb757dfc3c340ef03229e70dcabd3bdf93b1;hpb=f56af8e84db25c0d26fe762fbe171ec5518177bb;p=stockfish diff --git a/src/evaluate.cpp b/src/evaluate.cpp index f4b7fb75..b5b51d2c 100644 --- a/src/evaluate.cpp +++ b/src/evaluate.cpp @@ -1,13 +1,14 @@ /* - Glaurung, a UCI chess playing engine. - Copyright (C) 2004-2008 Tord Romstad + Stockfish, a UCI chess playing engine derived from Glaurung 2.1 + Copyright (C) 2004-2008 Tord Romstad (Glaurung author) + Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad - Glaurung is free software: you can redistribute it and/or modify + Stockfish is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. - Glaurung is distributed in the hope that it will be useful, + Stockfish is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. @@ -16,220 +17,198 @@ along with this program. If not, see . */ - -//// -//// Includes -//// - #include -#include +#include +#include +#include +#include "bitcount.h" #include "evaluate.h" #include "material.h" #include "pawns.h" -#include "scale.h" #include "thread.h" #include "ucioption.h" - -//// -//// Local definitions -//// - namespace { - const int Sign[2] = {1, -1}; + // Struct EvalInfo contains various information computed and collected + // by the evaluation functions. + struct EvalInfo { + + // Pointers to material and pawn hash table entries + MaterialEntry* mi; + PawnEntry* pi; + + // attackedBy[color][piece type] is a bitboard representing all squares + // attacked by a given color and piece type, attackedBy[color][0] contains + // all squares attacked by the given color. + Bitboard attackedBy[2][8]; + + // 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[2]; + + // kingAttackersCount[color] is the number of pieces of the given color + // which attack a square in the kingRing of the enemy king. + int kingAttackersCount[2]; + + // 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[2]; + + // 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[2]; + }; - // Evaluation grain size, must be a power of 2. - const int GrainSize = 4; + // Evaluation grain size, must be a power of 2 + const int GrainSize = 8; - // Evaluation weights - int WeightMobilityMidgame = 0x100; - int WeightMobilityEndgame = 0x100; - int WeightPawnStructureMidgame = 0x100; - int WeightPawnStructureEndgame = 0x100; - int WeightPassedPawnsMidgame = 0x100; - int WeightPassedPawnsEndgame = 0x100; - int WeightKingSafety[2] = { 0x100, 0x100 }; + // Evaluation weights, initialized from UCI options + enum { Mobility, PassedPawns, Space, KingDangerUs, KingDangerThem }; + Score Weights[6]; - // 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. - const int WeightMobilityMidgameInternal = 0x100; - const int WeightMobilityEndgameInternal = 0x100; - const int WeightPawnStructureMidgameInternal = 0x100; - const int WeightPawnStructureEndgameInternal = 0x100; - const int WeightPassedPawnsMidgameInternal = 0x100; - const int WeightPassedPawnsEndgameInternal = 0x100; - const int WeightKingSafetyInternal = 0x100; - - // Visually better to define tables constants typedef Value V; + #define S(mg, eg) make_score(mg, eg) - // Knight mobility bonus in middle game and endgame, indexed by the number - // of attacked squares not occupied by friendly piecess. - const Value MidgameKnightMobilityBonus[] = { - // 0 1 2 3 4 5 6 7 8 - V(-30), V(-20),V(-10), V(0), V(10), V(20), V(25), V(30), V(30) - }; - - const Value EndgameKnightMobilityBonus[] = { - // 0 1 2 3 4 5 6 7 8 - V(-30), V(-20),V(-10), V(0), V(10), V(20), V(25), V(30), V(30) - }; - - // Bishop mobility bonus in middle game and endgame, indexed by the number - // of attacked squares not occupied by friendly pieces. X-ray attacks through - // queens are also included. - const Value MidgameBishopMobilityBonus[] = { - // 0 1 2 3 4 5 6 7 - V(-30), V(-15), V(0), V(15), V(30), V(45), V(58), V(66), - // 8 9 10 11 12 13 14 15 - V( 72), V( 76), V(78), V(80), V(81), V(82), V(83), V(83) - }; - - const Value EndgameBishopMobilityBonus[] = { - // 0 1 2 3 4 5 6 7 - V(-30), V(-15), V(0), V(15), V(30), V(45), V(58), V(66), - // 8 9 10 11 12 13 14 15 - V( 72), V( 76), V(78), V(80), V(81), V(82), V(83), V(83) + // 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(252, 344), S(216, 266), S(46, 0), S(247, 0), S(259, 0) }; - // Rook mobility bonus in middle game and endgame, indexed by the number - // of attacked squares not occupied by friendly pieces. X-ray attacks through - // queens and rooks are also included. - const Value MidgameRookMobilityBonus[] = { - // 0 1 2 3 4 5 6 7 - V(-18), V(-12), V(-6), V(0), V(6), V(12), V(16), V(21), - // 8 9 10 11 12 13 14 15 - V( 24), V( 27), V(28), V(29), V(30), V(31), V(32), V(33) + // MobilityBonus[PieceType][attacked] contains mobility 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(-38,-33), S(-25,-23), S(-12,-13), S( 0, -3), S(12, 7), S(25, 17), // Knights + S( 31, 22), S( 38, 27), S( 38, 27) }, + { S(-25,-30), S(-11,-16), S( 3, -2), S(17, 12), S(31, 26), S(45, 40), // Bishops + 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) }, + { S(-20,-36), S(-14,-19), S( -8, -3), S(-2, 13), S( 4, 29), S(10, 46), // Rooks + 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) }, + { S(-10,-18), S( -8,-13), S( -6, -7), S(-3, -2), S(-1, 3), S( 1, 8), // Queens + S( 3, 13), S( 5, 19), S( 8, 23), S(10, 27), S(12, 32), S(15, 34), + S( 16, 35), S( 17, 35), S( 18, 35), S(20, 35), S(20, 35), S(20, 35), + S( 20, 35), S( 20, 35), S( 20, 35), S(20, 35), S(20, 35), S(20, 35), + S( 20, 35), S( 20, 35), S( 20, 35), S(20, 35), S(20, 35), S(20, 35), + S( 20, 35), S( 20, 35) } }; - const Value EndgameRookMobilityBonus[] = { - // 0 1 2 3 4 5 6 7 - V(-30), V(-18), V(-6), V(6), V(18), V(30), V(42), V(54), - // 8 9 10 11 12 13 14 15 - V( 66), V( 74), V(78), V(80), V(81), V(82), V(83), V(83) + // OutpostBonus[PieceType][Square] contains outpost bonuses of knights and + // bishops, indexed by piece type and square (from white's point of view). + const Value OutpostBonus[][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), // 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) } }; - // Queen mobility bonus in middle game and endgame, indexed by the number - // of attacked squares not occupied by friendly pieces. - const Value MidgameQueenMobilityBonus[] = { - // 0 1 2 3 4 5 6 7 - V(-10), V(-8), V(-6), V(-4), V(-2), V( 0), V( 2), V( 4), - // 8 9 10 11 12 13 14 15 - V( 6), V( 8), V(10), V(12), V(13), V(14), V(15), V(16), - // 16 17 18 19 20 21 22 23 - V( 16), V(16), V(16), V(16), V(16), V(16), V(16), V(16), - // 24 25 26 27 28 29 30 31 - V( 16), V(16), V(16), V(16), V(16), V(16), V(16), V(16) + // ThreatBonus[attacking][attacked] contains threat bonuses according to + // which piece type attacks which one. + const Score ThreatBonus[][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( 0, 22), 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 }; - const Value EndgameQueenMobilityBonus[] = { - // 0 1 2 3 4 5 6 7 - V(-20),V(-15),V(-10), V(-5), V( 0), V( 5), V(10), V(15), - // 8 9 10 11 12 13 14 15 - V( 19), V(23), V(27), V(29), V(30), V(30), V(30), V(30), - // 16 17 18 19 20 21 22 23 - V( 30), V(30), V(30), V(30), V(30), V(30), V(30), V(30), - // 24 25 26 27 28 29 30 31 - V( 30), V(30), V(30), V(30), V(30), V(30), V(30), V(30) + // ThreatenedByPawnPenalty[PieceType] contains a penalty according to which + // piece type is attacked by an enemy pawn. + const Score ThreatenedByPawnPenalty[] = { + S(0, 0), S(0, 0), S(56, 70), S(56, 70), S(76, 99), S(86, 118) }; - // 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(5),V(10),V(10), V(5), V(0), V(0), // 3 - V(0), V(5),V(20),V(30),V(30),V(20), V(5), V(0), // 4 - V(0),V(10),V(30),V(40),V(40),V(30),V(10), V(0), // 5 - V(0), V(5),V(20),V(20),V(20),V(20), 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 - }; + #undef S - 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(20),V(20),V(20),V(20),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 - }; + // Bonus for having the side to move (modified by Joona Kiiski) + const Score Tempo = make_score(24, 11); - // Bonus for unstoppable passed pawns: - const Value UnstoppablePawnValue = Value(0x500); + // Rooks and queens on the 7th rank + const Score RookOn7thBonus = make_score(3, 20); + const Score QueenOn7thBonus = make_score(1, 8); - // Rooks and queens on the 7th rank: - const Value MidgameRookOn7thBonus = Value(50); - const Value EndgameRookOn7thBonus = Value(100); - const Value MidgameQueenOn7thBonus = Value(25); - const Value EndgameQueenOn7thBonus = Value(50); + // Rooks and queens attacking pawns on the same rank + const Score RookOnPawnBonus = make_score(3, 48); + const Score QueenOnPawnBonus = make_score(1, 40); - // Rooks on open files: - const Value RookOpenFileBonus = Value(40); - const Value RookHalfOpenFileBonus = Value(20); + // Rooks on open files (modified by Joona Kiiski) + const Score RookOpenFileBonus = make_score(43, 21); + const Score RookHalfOpenFileBonus = make_score(19, 10); // Penalty for rooks trapped inside a friendly king which has lost the - // right to castle: + // right to castle. const Value TrappedRookPenalty = Value(180); - // Penalty for a bishop on a7/h7 (a2/h2 for black) which is trapped by - // enemy pawns: - const Value TrappedBishopA7H7Penalty = Value(300); - - // 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)) - }; - // 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 + // a friendly pawn on b2/g2 (b7/g7 for black). This can obviously only // happen in Chess960 games. - const Value TrappedBishopA1H1Penalty = Value(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 TrappedBishopA1H1Penalty = make_score(100, 100); + + // Penalty for an undefended bishop or knight + const Score UndefendedMinorPenalty = make_score(25, 10); + + // 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[] = { + (1ULL << SQ_C2) | (1ULL << SQ_D2) | (1ULL << SQ_E2) | (1ULL << SQ_F2) | + (1ULL << SQ_C3) | (1ULL << SQ_D3) | (1ULL << SQ_E3) | (1ULL << SQ_F3) | + (1ULL << SQ_C4) | (1ULL << SQ_D4) | (1ULL << SQ_E4) | (1ULL << SQ_F4), + (1ULL << SQ_C7) | (1ULL << SQ_D7) | (1ULL << SQ_E7) | (1ULL << SQ_F7) | + (1ULL << SQ_C6) | (1ULL << SQ_D6) | (1ULL << SQ_E6) | (1ULL << SQ_F6) | + (1ULL << SQ_C5) | (1ULL << SQ_D5) | (1ULL << SQ_E5) | (1ULL << SQ_F5) }; - /// King safety constants and variables. The king safety scores are taken - /// from the array SafetyTable[]. Various little "meta-bonuses" measuring - /// the strength of the attack are added up into an integer, which is used - /// as an index to SafetyTable[]. - - // Attack weights for each piece type. - const int QueenAttackWeight = 5; - const int RookAttackWeight = 3; - const int BishopAttackWeight = 2; - const int KnightAttackWeight = 2; - - // Bonuses for safe checks for each piece type. - int QueenContactCheckBonus = 4; - int RookContactCheckBonus = 2; - int QueenCheckBonus = 2; - int RookCheckBonus = 1; - int BishopCheckBonus = 1; - int KnightCheckBonus = 1; - int DiscoveredCheckBonus = 3; - - // Scan for queen contact mates? - const bool QueenContactMates = true; - - // Bonus for having a mate threat. - int MateThreatBonus = 3; - - // InitKingDanger[] contains bonuses based on the position of the defending - // king. - const int InitKingDanger[64] = { + // King danger constants and variables. The king danger scores are taken + // from the KingDangerTable[]. Various little "meta-bonuses" measuring + // the strength of the enemy attack are added up into an integer, which + // is used as an index to KingDangerTable[]. + // + // KingAttackWeights[PieceType] contains king attack weights by piece type + const int KingAttackWeights[] = { 0, 0, 2, 2, 3, 5 }; + + // Bonuses for enemy's safe checks + const int QueenContactCheckBonus = 6; + const int RookContactCheckBonus = 4; + const int QueenCheckBonus = 3; + const int RookCheckBonus = 2; + const int BishopCheckBonus = 1; + const int KnightCheckBonus = 1; + + // InitKingDanger[Square] contains penalties based on the position of the + // defending king, indexed by king's square (from white's point of view). + const int InitKingDanger[] = { 2, 0, 2, 5, 5, 2, 0, 2, 2, 2, 4, 8, 8, 4, 2, 2, 7, 10, 12, 12, 12, 12, 10, 7, @@ -240,963 +219,1001 @@ namespace { 15, 15, 15, 15, 15, 15, 15, 15 }; - // SafetyTable[] contains the actual king safety scores. It is initialized - // in init_safety(). - Value SafetyTable[100]; + // KingDangerTable[Color][attackUnits] contains the actual king danger + // weighted scores, indexed by color and by a calculated integer number. + Score KingDangerTable[2][128]; + + // TracedTerms[Color][PieceType || TracedType] contains a breakdown of the + // evaluation terms, used when tracing. + Score TracedScores[2][16]; + std::stringstream TraceStream; + + enum TracedType { + PST = 8, IMBALANCE = 9, MOBILITY = 10, THREAT = 11, + PASSED = 12, UNSTOPPABLE = 13, SPACE = 14, TOTAL = 15 + }; - // Pawn and material hash tables, indexed by the current thread id: - PawnInfoTable *PawnTable[8] = {0, 0, 0, 0, 0, 0, 0, 0}; - MaterialInfoTable *MaterialTable[8] = {0, 0, 0, 0, 0, 0, 0, 0}; + // Function prototypes + template + Value do_evaluate(const Position& pos, Value& margin); - // Sizes of pawn and material hash tables: - const int PawnTableSize = 16384; - const int MaterialTableSize = 1024; + template + void init_eval_info(const Position& pos, EvalInfo& ei); - // Array which gives the number of nonzero bits in an 8-bit integer: - uint8_t BitCount8Bit[256]; + template + Score evaluate_pieces_of_color(const Position& pos, EvalInfo& ei, Score& mobility); - // Function prototypes: - void evaluate_knight(const Position &p, Square s, Color us, EvalInfo &ei); - void evaluate_bishop(const Position &p, Square s, Color us, EvalInfo &ei); - void evaluate_rook(const Position &p, Square s, Color us, EvalInfo &ei); - void evaluate_queen(const Position &p, Square s, Color us, EvalInfo &ei); - void evaluate_king(const Position &p, Square s, Color us, EvalInfo &ei); + template + Score evaluate_king(const Position& pos, EvalInfo& ei, Value margins[]); - 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); + template + Score evaluate_threats(const Position& pos, EvalInfo& ei); - inline Value apply_weight(Value v, int w); - Value scale_by_game_phase(Value mv, Value ev, Phase ph, ScaleFactor sf[]); + template + int evaluate_space(const Position& pos, EvalInfo& ei); - int count_1s_8bit(Bitboard b); + template + Score evaluate_passed_pawns(const Position& pos, EvalInfo& ei); - int compute_weight(int uciWeight, int internalWeight); - void init_safety(); + Score evaluate_unstoppable_pawns(const Position& pos, EvalInfo& ei); + Value interpolate(const Score& v, Phase ph, ScaleFactor sf); + Score weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight); + double to_cp(Value v); + void trace_add(int idx, Score term_w, Score term_b = SCORE_ZERO); + void trace_row(const char* name, int idx); } -//// -//// Functions -//// +namespace Eval { -/// 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. + Color RootColor; -Value evaluate(const Position &pos, EvalInfo &ei, int threadID) { - Color stm; - Square s; - ScaleFactor factor[2] = {SCALE_FACTOR_NORMAL, SCALE_FACTOR_NORMAL}; - Phase phase; + /// 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. - memset(&ei, 0, sizeof(EvalInfo)); + Value evaluate(const Position& pos, Value& margin) { + return do_evaluate(pos, margin); + } - assert(pos.is_ok()); - assert(threadID >= 0 && threadID < THREAD_MAX); - stm = pos.side_to_move(); + /// init() computes evaluation weights from the corresponding UCI parameters + /// and setup king tables. - // Initialize by reading the incrementally updated scores included in the - // position object (material + piece square tables): - ei.mgValue = pos.mg_value(); - ei.egValue = pos.eg_value(); + void init() { - // Probe the material hash table: - ei.mi = MaterialTable[threadID]->get_material_info(pos); - ei.mgValue += ei.mi->mg_value(); - ei.egValue += ei.mi->eg_value(); + Weights[Mobility] = weight_option("Mobility (Middle Game)", "Mobility (Endgame)", WeightsInternal[Mobility]); + 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]); - factor[WHITE] = ei.mi->scale_factor(pos, WHITE); - factor[BLACK] = ei.mi->scale_factor(pos, BLACK); + // King safety is asymmetrical. Our king danger level is weighted by + // "Cowardice" UCI parameter, instead the opponent one by "Aggressiveness". + // 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 (Options["UCI_AnalyseMode"]) + Weights[KingDangerUs] = Weights[KingDangerThem] = (Weights[KingDangerUs] + Weights[KingDangerThem]) / 2; - // 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); - - phase = pos.game_phase(); - - // Probe the pawn hash table: - ei.pi = PawnTable[threadID]->get_pawn_info(pos); - ei.mgValue += apply_weight(ei.pi->mg_value(), WeightPawnStructureMidgame); - ei.egValue += apply_weight(ei.pi->eg_value(), WeightPawnStructureEndgame); - - // Initialize king attack bitboards and king attack zones for both sides: - ei.attackedBy[WHITE][KING] = pos.king_attacks(pos.king_square(WHITE)); - ei.attackedBy[BLACK][KING] = pos.king_attacks(pos.king_square(BLACK)); - ei.attackZone[WHITE] = - ei.attackedBy[BLACK][KING] | (ei.attackedBy[BLACK][KING] >> 8); - ei.attackZone[BLACK] = - ei.attackedBy[WHITE][KING] | (ei.attackedBy[WHITE][KING] << 8); - - // Initialize pawn attack bitboards for both sides: - ei.attackedBy[WHITE][PAWN] = - ((pos.pawns(WHITE) << 9) & ~FileABB) | ((pos.pawns(WHITE) << 7) & ~FileHBB); - ei.attackCount[WHITE] += - count_1s_max_15(ei.attackedBy[WHITE][PAWN] & ei.attackedBy[BLACK][KING])/2; - ei.attackedBy[BLACK][PAWN] = - ((pos.pawns(BLACK) >> 7) & ~FileABB) | ((pos.pawns(BLACK) >> 9) & ~FileHBB); - ei.attackCount[BLACK] += - count_1s_max_15(ei.attackedBy[BLACK][PAWN] & ei.attackedBy[WHITE][KING])/2; - - // Evaluate pieces: - for(Color c = WHITE; c <= BLACK; c++) { - Bitboard b; + const int MaxSlope = 30; + const int Peak = 1280; - // Knights - for(int i = 0; i < pos.knight_count(c); i++) { - s = pos.knight_list(c, i); - evaluate_knight(pos, s, c, ei); - } + for (int t = 0, i = 1; i < 100; i++) + { + t = std::min(Peak, std::min(int(0.4 * i * i), t + MaxSlope)); - // Bishops - for(int i = 0; i < pos.bishop_count(c); i++) { - s = pos.bishop_list(c, i); - evaluate_bishop(pos, s, c, ei); + KingDangerTable[1][i] = apply_weight(make_score(t, 0), Weights[KingDangerUs]); + KingDangerTable[0][i] = apply_weight(make_score(t, 0), Weights[KingDangerThem]); } + } - // Rooks - for(int i = 0; i < pos.rook_count(c); i++) { - s = pos.rook_list(c, i); - evaluate_rook(pos, s, c, ei); - } - // Queens - for(int i = 0; i < pos.queen_count(c); i++) { - s = pos.queen_list(c, i); - evaluate_queen(pos, s, c, ei); - } + /// trace() is like evaluate() but instead of a value returns a string suitable + /// to be print on stdout with the detailed descriptions and values of each + /// evaluation term. Used mainly for debugging. - // Some special patterns: + std::string trace(const Position& pos) { - // Trapped bishops on a7/h7/a2/h2 - b = pos.bishops(c) & MaskA7H7[c]; - while(b) { - s = pop_1st_bit(&b); - evaluate_trapped_bishop_a7h7(pos, s, c, ei); - } + Value margin; + std::string totals; - // Trapped bishops on a1/h1/a8/h8 in Chess960: - if(Chess960) { - b = pos.bishops(c) & MaskA1H1[c]; - while(b) { - s = pop_1st_bit(&b); - evaluate_trapped_bishop_a1h1(pos, s, c, ei); - } - } + RootColor = pos.side_to_move(); - ei.attackedBy[c][0] = - ei.attackedBy[c][PAWN] | ei.attackedBy[c][KNIGHT] - | ei.attackedBy[c][BISHOP] | ei.attackedBy[c][ROOK] - | ei.attackedBy[c][QUEEN] | ei.attackedBy[c][KING]; - } + TraceStream.str(""); + TraceStream << std::showpoint << std::showpos << std::fixed << std::setprecision(2); + memset(TracedScores, 0, 2 * 16 * sizeof(Score)); - // 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. - for(Color c = WHITE; c <= BLACK; c++) { - s = pos.king_square(c); - evaluate_king(pos, s, c, ei); - } + do_evaluate(pos, margin); - // Evaluate passed pawns. We evaluate passed pawns for both sides at once, - // because we need to know which side promotes first in positions where - // both sides have an unstoppable passed pawn. - if(ei.pi->passed_pawns()) - evaluate_passed_pawns(pos, ei); - - // Middle-game specific evaluation terms - if(phase > PHASE_ENDGAME) { - - // Pawn storms in positions with opposite castling. - if(square_file(pos.king_square(WHITE)) >= FILE_E && - square_file(pos.king_square(BLACK)) <= FILE_D) - ei.mgValue += - ei.pi->queenside_storm_value(WHITE) - - ei.pi->kingside_storm_value(BLACK); - else if(square_file(pos.king_square(WHITE)) <= FILE_D && - square_file(pos.king_square(BLACK)) >= FILE_E) - ei.mgValue += - ei.pi->kingside_storm_value(WHITE) - - ei.pi->queenside_storm_value(BLACK); - } + totals = TraceStream.str(); + TraceStream.str(""); - // Mobility - ei.mgValue += apply_weight(ei.mgMobility, WeightMobilityMidgame); - ei.egValue += apply_weight(ei.egMobility, WeightMobilityEndgame); + TraceStream << std::setw(21) << "Eval term " << "| White | Black | Total \n" + << " | MG EG | MG EG | MG EG \n" + << "---------------------+-------------+-------------+---------------\n"; - // If we don't already have an unusual scale factor, check for opposite - // colored bishop endgames, and use a lower scale for those: - if(phase < PHASE_MIDGAME && pos.opposite_colored_bishops() - && ((factor[WHITE] == SCALE_FACTOR_NORMAL && ei.egValue > Value(0)) || - (factor[BLACK] == SCALE_FACTOR_NORMAL && ei.egValue < Value(0)))) { - if(pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) == - 2*BishopValueMidgame) { - // Only the two bishops - if(pos.pawn_count(WHITE) + pos.pawn_count(BLACK) == 1) { - // KBP vs KB with only a single pawn; almost certainly a draw. - if(factor[WHITE] == SCALE_FACTOR_NORMAL) - factor[WHITE] = ScaleFactor(8); - if(factor[BLACK] == SCALE_FACTOR_NORMAL) - factor[BLACK] = ScaleFactor(8); - } - else { - // At least two pawns - if(factor[WHITE] == SCALE_FACTOR_NORMAL) - factor[WHITE] = ScaleFactor(32); - if(factor[BLACK] == SCALE_FACTOR_NORMAL) - factor[BLACK] = 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. - if(factor[WHITE] == SCALE_FACTOR_NORMAL) - factor[WHITE] = ScaleFactor(50); - if(factor[BLACK] == SCALE_FACTOR_NORMAL) - factor[BLACK] = ScaleFactor(50); - } + trace_row("Material, PST, Tempo", PST); + trace_row("Material imbalance", IMBALANCE); + trace_row("Pawns", PAWN); + trace_row("Knights", KNIGHT); + trace_row("Bishops", BISHOP); + trace_row("Rooks", ROOK); + trace_row("Queens", QUEEN); + trace_row("Mobility", MOBILITY); + trace_row("King safety", KING); + trace_row("Threats", THREAT); + trace_row("Passed pawns", PASSED); + trace_row("Unstoppable pawns", UNSTOPPABLE); + trace_row("Space", SPACE); + + TraceStream << "---------------------+-------------+-------------+---------------\n"; + trace_row("Total", TOTAL); + TraceStream << totals; + + return TraceStream.str(); } - // Interpolate between the middle game and the endgame score, and - // return: - Value value = scale_by_game_phase(ei.mgValue, ei.egValue, phase, factor); +} // namespace Eval - if(ei.mateThreat[stm] != MOVE_NONE) - return 8 * QueenValueMidgame - Sign[stm] * value; - else - return Sign[stm] * value; -} +namespace { -/// quick_evaluate() does a very approximate evaluation of the current position. -/// It currently considers only material and piece square table scores. Perhaps -/// we should add scores from the pawn and material hash tables? +template +Value do_evaluate(const Position& pos, Value& margin) { -Value quick_evaluate(const Position &pos) { - Color stm; - Value mgValue, egValue; - ScaleFactor factor[2] = {SCALE_FACTOR_NORMAL, SCALE_FACTOR_NORMAL}; - Phase phase; + assert(!pos.in_check()); - assert(pos.is_ok()); + EvalInfo ei; + Value margins[2]; + Score score, mobilityWhite, mobilityBlack; - stm = pos.side_to_move(); + // margins[] store the uncertainty estimation of position's evaluation + // that typically is used by the search for pruning decisions. + margins[WHITE] = margins[BLACK] = VALUE_ZERO; - mgValue = pos.mg_value(); - egValue = pos.eg_value(); - phase = pos.game_phase(); + // Initialize score by reading the incrementally updated scores included + // in the position object (material + piece square tables) and adding + // Tempo bonus. Score is computed from the point of view of white. + score = pos.psq_score() + (pos.side_to_move() == WHITE ? Tempo : -Tempo); - Value value = scale_by_game_phase(mgValue, egValue, phase, factor); + // Probe the material hash table + ei.mi = pos.this_thread()->materialTable.probe(pos); + score += ei.mi->material_value(); - return Sign[stm] * value; -} + // If we have a specialized evaluation function for the current material + // configuration, call it and return. + if (ei.mi->specialized_eval_exists()) + { + margin = VALUE_ZERO; + return ei.mi->evaluate(pos); + } + + // Probe the pawn hash table + ei.pi = pos.this_thread()->pawnTable.probe(pos); + score += ei.pi->pawns_value(); + // Initialize attack and king safety bitboards + init_eval_info(pos, ei); + init_eval_info(pos, ei); -/// init_eval() initializes various tables used by the evaluation function. + // Evaluate pieces and mobility + score += evaluate_pieces_of_color(pos, ei, mobilityWhite) + - evaluate_pieces_of_color(pos, ei, mobilityBlack); -void init_eval(int threads) { + score += apply_weight(mobilityWhite - mobilityBlack, Weights[Mobility]); - assert(threads <= THREAD_MAX); + // Evaluate kings after all other pieces because we need complete attack + // information when computing the king safety evaluation. + score += evaluate_king(pos, ei, margins) + - evaluate_king(pos, ei, margins); - for (int i = 0; i < THREAD_MAX; i++) + // 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 one side has only a king, check whether exists any unstoppable passed pawn + if (!pos.non_pawn_material(WHITE) || !pos.non_pawn_material(BLACK)) + score += evaluate_unstoppable_pawns(pos, ei); + + // Evaluate space for both sides, only in middle-game. + if (ei.mi->space_weight()) { - if (i >= threads) - { - delete PawnTable[i]; - delete MaterialTable[i]; - PawnTable[i] = NULL; - MaterialTable[i] = NULL; - continue; - } - if (!PawnTable[i]) - PawnTable[i] = new PawnInfoTable(PawnTableSize); - if (!MaterialTable[i]) - MaterialTable[i] = new MaterialInfoTable(MaterialTableSize); + int s = evaluate_space(pos, ei) - evaluate_space(pos, ei); + score += apply_weight(make_score(s * ei.mi->space_weight(), 0), Weights[Space]); } - for (Bitboard b = 0ULL; b < 256ULL; b++) - BitCount8Bit[b] = count_1s(b); -} + // Scale winning side if position is more drawish that what it appears + ScaleFactor sf = eg_value(score) > VALUE_DRAW ? ei.mi->scale_factor(pos, WHITE) + : ei.mi->scale_factor(pos, BLACK); + // If we don't already have an unusual scale factor, check for opposite + // colored bishop endgames, and use a lower scale for those. + if ( ei.mi->game_phase() < PHASE_MIDGAME + && pos.opposite_bishops() + && sf == SCALE_FACTOR_NORMAL) + { + // Only the two bishops ? + 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.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); + } -/// quit_eval() releases heap-allocated memory at program termination. + margin = margins[pos.side_to_move()]; + Value v = interpolate(score, ei.mi->game_phase(), sf); -void quit_eval() { - for(int i = 0; i < THREAD_MAX; i++) { - delete PawnTable[i]; - delete MaterialTable[i]; + // In case of tracing add all single evaluation contributions for both white and black + if (Trace) + { + trace_add(PST, pos.psq_score()); + trace_add(IMBALANCE, ei.mi->material_value()); + trace_add(PAWN, ei.pi->pawns_value()); + trace_add(MOBILITY, apply_weight(mobilityWhite, Weights[Mobility]), apply_weight(mobilityBlack, Weights[Mobility])); + trace_add(THREAT, evaluate_threats(pos, ei), evaluate_threats(pos, ei)); + trace_add(PASSED, evaluate_passed_pawns(pos, ei), evaluate_passed_pawns(pos, ei)); + trace_add(UNSTOPPABLE, evaluate_unstoppable_pawns(pos, ei)); + Score w = make_score(ei.mi->space_weight() * evaluate_space(pos, ei), 0); + Score b = make_score(ei.mi->space_weight() * evaluate_space(pos, ei), 0); + trace_add(SPACE, apply_weight(w, Weights[Space]), apply_weight(b, Weights[Space])); + trace_add(TOTAL, score); + TraceStream << "\nUncertainty margin: White: " << to_cp(margins[WHITE]) + << ", Black: " << to_cp(margins[BLACK]) + << "\nScaling: " << std::noshowpos + << std::setw(6) << 100.0 * ei.mi->game_phase() / 128.0 << "% MG, " + << std::setw(6) << 100.0 * (1.0 - ei.mi->game_phase() / 128.0) << "% * " + << std::setw(6) << (100.0 * sf) / SCALE_FACTOR_NORMAL << "% EG.\n" + << "Total evaluation: " << to_cp(v); } -} - -/// read_weights() reads evaluation weights from the corresponding UCI -/// parameters. - -void read_weights(Color sideToMove) { - WeightMobilityMidgame = - compute_weight(get_option_value_int("Mobility (Middle Game)"), - WeightMobilityMidgameInternal); - WeightMobilityEndgame = - compute_weight(get_option_value_int("Mobility (Endgame)"), - WeightMobilityEndgameInternal); - WeightPawnStructureMidgame = - compute_weight(get_option_value_int("Pawn Structure (Middle Game)"), - WeightPawnStructureMidgameInternal); - WeightPawnStructureEndgame = - compute_weight(get_option_value_int("Pawn Structure (Endgame)"), - WeightPawnStructureEndgameInternal); - WeightPassedPawnsMidgame = - compute_weight(get_option_value_int("Passed Pawns (Middle Game)"), - WeightPassedPawnsMidgameInternal); - WeightPassedPawnsEndgame = - compute_weight(get_option_value_int("Passed Pawns (Endgame)"), - WeightPassedPawnsEndgameInternal); - WeightKingSafety[sideToMove] = - compute_weight(get_option_value_int("Cowardice"), WeightKingSafetyInternal); - WeightKingSafety[opposite_color(sideToMove)] = - compute_weight(get_option_value_int("Aggressiveness"), - WeightKingSafetyInternal); - WeightKingSafety[opposite_color(sideToMove)] = - (get_option_value_int("Aggressiveness") * 0x100) / 100; - - init_safety(); + return pos.side_to_move() == WHITE ? v : -v; } -namespace { + // init_eval_info() initializes king bitboards for given color adding + // pawn attacks. To be done at the beginning of the evaluation. - // evaluate_common() computes terms common to all pieces attack + template + void init_eval_info(const Position& pos, EvalInfo& ei) { - int evaluate_common(const Position&p, const Bitboard& b, Color us, EvalInfo& ei, - int AttackWeight, const Value* mgBonus, const Value* egBonus, - Square s = SQ_NONE, const Value* OutpostBonus = NULL) { + const Color Them = (Us == WHITE ? BLACK : WHITE); - Color them = opposite_color(us); + Bitboard b = ei.attackedBy[Them][KING] = pos.attacks_from(pos.king_square(Them)); + ei.attackedBy[Us][PAWN] = ei.pi->pawn_attacks(Us); - // King attack - if (b & ei.attackZone[us]) + // Init king safety tables only if we are going to use them + if ( pos.piece_count(Us, QUEEN) + && pos.non_pawn_material(Us) >= QueenValueMg + RookValueMg) { - ei.attackCount[us]++; - ei.attackWeight[us] += AttackWeight; - Bitboard bb = (b & ei.attackedBy[them][KING]); - if (bb) - ei.attacked[us] += count_1s_max_15(bb); - } + ei.kingRing[Them] = (b | (Us == WHITE ? b >> 8 : b << 8)); + b &= ei.attackedBy[Us][PAWN]; + ei.kingAttackersCount[Us] = b ? popcount(b) / 2 : 0; + ei.kingAdjacentZoneAttacksCount[Us] = ei.kingAttackersWeight[Us] = 0; + } else + ei.kingRing[Them] = ei.kingAttackersCount[Us] = 0; + } + - // Mobility - int mob = count_1s_max_15(b & ~p.pieces_of_color(us)); - ei.mgMobility += Sign[us] * mgBonus[mob]; - ei.egMobility += Sign[us] * egBonus[mob]; + // evaluate_outposts() evaluates bishop and knight outposts squares - // Bishop and Knight outposts - if (!OutpostBonus || !p.square_is_weak(s, them)) - return mob; + template + Score evaluate_outposts(const Position& pos, EvalInfo& ei, Square s) { + + const Color Them = (Us == WHITE ? BLACK : WHITE); + + assert (Piece == BISHOP || Piece == KNIGHT); // Initial bonus based on square - Value v, bonus; - v = bonus = OutpostBonus[relative_square(us, s)]; + Value bonus = OutpostBonus[Piece == 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 (v && (p.pawn_attacks(them, s) & p.pawns(us))) + // no minor piece which can exchange the outpost piece. + if (bonus && (ei.attackedBy[Us][PAWN] & s)) { - bonus += v / 2; - if ( p.knight_count(them) == 0 - && (SquaresByColorBB[square_color(s)] & p.bishops(them)) == EmptyBoardBB) - bonus += v; + if ( !pos.pieces(Them, KNIGHT) + && !(same_color_squares(s) & pos.pieces(Them, BISHOP))) + bonus += bonus + bonus / 2; + else + bonus += bonus / 2; } - ei.mgValue += Sign[us] * bonus; - ei.egValue += Sign[us] * bonus; - return mob; + return make_score(bonus, bonus); } - // evaluate_knight() assigns bonuses and penalties to a knight of a given - // color on a given square. + // evaluate_pieces<>() assigns bonuses and penalties to the pieces of a given color - void evaluate_knight(const Position &p, Square s, Color us, EvalInfo &ei) { + template + Score evaluate_pieces(const Position& pos, EvalInfo& ei, Score& mobility, Bitboard mobilityArea) { - Bitboard b = p.knight_attacks(s); - ei.attackedBy[us][KNIGHT] |= b; + Bitboard b; + Square s, ksq; + int mob; + File f; + Score score = SCORE_ZERO; - // King attack, mobility and outposts - evaluate_common(p, b, us, ei, KnightAttackWeight, MidgameKnightMobilityBonus, - EndgameKnightMobilityBonus, s, KnightOutpostBonus); - } + const Color Them = (Us == WHITE ? BLACK : WHITE); + const Square* pl = pos.piece_list(Us, Piece); + ei.attackedBy[Us][Piece] = 0; - // evaluate_bishop() assigns bonuses and penalties to a bishop of a given - // color on a given square. + 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 = attacks_bb(s, pos.pieces() ^ pos.pieces(Us, QUEEN)); + else if (Piece == ROOK) + b = attacks_bb(s, pos.pieces() ^ pos.pieces(Us, ROOK, QUEEN)); + else + assert(false); - void evaluate_bishop(const Position &p, Square s, Color us, EvalInfo &ei) { + ei.attackedBy[Us][Piece] |= b; - Bitboard b = bishop_attacks_bb(s, p.occupied_squares() & ~p.queens(us)); - ei.attackedBy[us][BISHOP] |= b; + if (b & ei.kingRing[Them]) + { + ei.kingAttackersCount[Us]++; + ei.kingAttackersWeight[Us] += KingAttackWeights[Piece]; + Bitboard bb = (b & ei.attackedBy[Them][KING]); + if (bb) + ei.kingAdjacentZoneAttacksCount[Us] += popcount(bb); + } - // King attack, mobility and outposts - evaluate_common(p, b, us, ei, BishopAttackWeight, MidgameBishopMobilityBonus, - EndgameBishopMobilityBonus, s, BishopOutpostBonus); - } + mob = (Piece != QUEEN ? popcount(b & mobilityArea) + : popcount(b & mobilityArea)); + mobility += MobilityBonus[Piece][mob]; - // evaluate_rook() assigns bonuses and penalties to a rook of a given - // color on a given square. + // Add a bonus if a slider is pinning an enemy piece + if ( (Piece == BISHOP || Piece == ROOK || Piece == QUEEN) + && (PseudoAttacks[Piece][pos.king_square(Them)] & s)) + { + b = BetweenBB[s][pos.king_square(Them)] & pos.pieces(); - void evaluate_rook(const Position &p, Square s, Color us, EvalInfo &ei) { + assert(b); - //Bitboard b = p.rook_attacks(s); - Bitboard b = rook_attacks_bb(s, p.occupied_squares() & ~p.rooks_and_queens(us)); - ei.attackedBy[us][ROOK] |= b; + if (!more_than_one(b) && (b & pos.pieces(Them))) + score += ThreatBonus[Piece][type_of(pos.piece_on(lsb(b)))]; + } - // King attack and mobility - int mob = evaluate_common(p, b, us, ei, RookAttackWeight, MidgameRookMobilityBonus, - EndgameRookMobilityBonus); + // 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 (ei.attackedBy[Them][PAWN] & s) + score -= ThreatenedByPawnPenalty[Piece]; - // Rook on 7th rank - Color them = opposite_color(us); + // Bishop and knight outposts squares + if ( (Piece == BISHOP || Piece == KNIGHT) + && !(pos.pieces(Them, PAWN) & attack_span_mask(Us, s))) + score += evaluate_outposts(pos, ei, s); - if ( relative_rank(us, s) == RANK_7 - && relative_rank(us, p.king_square(them)) == RANK_8) - { - ei.mgValue += Sign[us] * MidgameRookOn7thBonus; - ei.egValue += Sign[us] * EndgameRookOn7thBonus; - } + if ((Piece == ROOK || Piece == QUEEN) && relative_rank(Us, s) >= RANK_5) + { + // Major piece on 7th rank + if ( relative_rank(Us, s) == RANK_7 + && relative_rank(Us, pos.king_square(Them)) == RANK_8) + score += (Piece == ROOK ? RookOn7thBonus : QueenOn7thBonus); + + // Major piece attacking pawns on the same rank + Bitboard pawns = pos.pieces(Them, PAWN) & rank_bb(s); + if (pawns) + score += (Piece == ROOK ? RookOnPawnBonus + : QueenOnPawnBonus) * popcount(pawns); + } - // Open and half-open files - File f = square_file(s); - if (ei.pi->file_is_half_open(us, f)) - { - if (ei.pi->file_is_half_open(them, f)) + // Special extra evaluation for bishops + if (Piece == BISHOP && pos.is_chess960()) { - ei.mgValue += Sign[us] * RookOpenFileBonus; - ei.egValue += Sign[us] * RookOpenFileBonus; + // 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 (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)) + { + if (!pos.is_empty(s + d + pawn_push(Us))) + score -= 2*TrappedBishopA1H1Penalty; + else if (pos.piece_on(s + 2*d) == make_piece(Us, PAWN)) + score -= TrappedBishopA1H1Penalty; + else + score -= TrappedBishopA1H1Penalty / 2; + } + } } - else + + // Special extra evaluation for rooks + if (Piece == ROOK) { - ei.mgValue += Sign[us] * RookHalfOpenFileBonus; - ei.egValue += Sign[us] * RookHalfOpenFileBonus; + // Open and half-open files + f = file_of(s); + if (ei.pi->file_is_half_open(Us, f)) + { + if (ei.pi->file_is_half_open(Them, f)) + score += RookOpenFileBonus; + else + score += RookHalfOpenFileBonus; + } + + // 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); + + if ( file_of(ksq) >= FILE_E + && file_of(s) > file_of(ksq) + && (relative_rank(Us, ksq) == RANK_1 || rank_of(ksq) == rank_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, file_of(ksq))) + score -= make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2 + : (TrappedRookPenalty - mob * 16), 0); + } + else if ( file_of(ksq) <= FILE_D + && file_of(s) < file_of(ksq) + && (relative_rank(Us, ksq) == RANK_1 || rank_of(ksq) == rank_of(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, file_of(ksq))) + score -= make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2 + : (TrappedRookPenalty - mob * 16), 0); + } } } - // 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)) - return; - - Square ksq = p.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.mgValue -= p.can_castle(us)? Sign[us] * ((TrappedRookPenalty - mob * 16) / 2) - : Sign[us] * (TrappedRookPenalty - mob * 16); - } - else if ( square_file(ksq) <= FILE_D - && square_file(s) < square_file(ksq) - && (relative_rank(us, ksq) == RANK_1 || square_rank(ksq) == square_rank(s))) - { - // Is there a half-open file between the king and the edge of the board? - if (!ei.pi->has_open_file_to_left(us, square_file(ksq))) - ei.mgValue -= p.can_castle(us)? Sign[us] * ((TrappedRookPenalty - mob * 16) / 2) - : Sign[us] * (TrappedRookPenalty - mob * 16); - } + if (Trace) + TracedScores[Us][Piece] = score; + + return score; } - // evaluate_queen() assigns bonuses and penalties to a queen of a given - // color on a given square. + // evaluate_threats<>() assigns bonuses according to the type of attacking piece + // and the type of attacked one. + + template + Score evaluate_threats(const Position& pos, EvalInfo& ei) { - void evaluate_queen(const Position &p, Square s, Color us, EvalInfo &ei) { + const Color Them = (Us == WHITE ? BLACK : WHITE); - Bitboard b = p.queen_attacks(s); - ei.attackedBy[us][QUEEN] |= b; + Bitboard b, undefendedMinors, weakEnemies; + Score score = SCORE_ZERO; - // King attack and mobility - evaluate_common(p, b, us, ei, QueenAttackWeight, MidgameQueenMobilityBonus, - EndgameQueenMobilityBonus); + // Undefended minors get penalized even if not under attack + undefendedMinors = pos.pieces(Them) + & (pos.pieces(BISHOP) | pos.pieces(KNIGHT)) + & ~ei.attackedBy[Them][0]; - // Queen on 7th rank - Color them = opposite_color(us); + if (undefendedMinors) + score += more_than_one(undefendedMinors) ? UndefendedMinorPenalty * 2 + : UndefendedMinorPenalty; - if ( relative_rank(us, s) == RANK_7 - && relative_rank(us, p.king_square(them)) == RANK_8) + // Enemy pieces not defended by a pawn and under our attack + weakEnemies = pos.pieces(Them) + & ~ei.attackedBy[Them][PAWN] + & ei.attackedBy[Us][0]; + + if (!weakEnemies) + return score; + + // Add bonus according to type of attacked enemy piece and to the + // type of attacking piece, from knights to queens. Kings are not + // considered because are already handled in king evaluation. + for (PieceType pt1 = KNIGHT; pt1 < KING; pt1++) { - ei.mgValue += Sign[us] * MidgameQueenOn7thBonus; - ei.egValue += Sign[us] * EndgameQueenOn7thBonus; + b = ei.attackedBy[Us][pt1] & weakEnemies; + if (b) + for (PieceType pt2 = PAWN; pt2 < KING; pt2++) + if (b & pos.pieces(pt2)) + score += ThreatBonus[pt1][pt2]; } + return score; } - // evaluate_king() assigns bonuses and penalties to a king of a given - // color on a given square. + // evaluate_pieces_of_color<>() assigns bonuses and penalties to all the + // pieces of a given color. - void evaluate_king(const Position &p, Square s, Color us, EvalInfo &ei) { + template + Score evaluate_pieces_of_color(const Position& pos, EvalInfo& ei, Score& mobility) { - int shelter = 0, sign = Sign[us]; + const Color Them = (Us == WHITE ? BLACK : WHITE); - // King shelter. - if(relative_rank(us, s) <= RANK_4) { - Bitboard pawns = p.pawns(us) & this_and_neighboring_files_bb(s); - Rank r = square_rank(s); - for(int i = 0; i < 3; i++) - shelter += count_1s_8bit(pawns >> ((r+(i+1)*sign) * 8)) * (64>>i); - ei.mgValue += sign * Value(shelter); - } + Score score = mobility = SCORE_ZERO; - // King safety. This is quite complicated, and is almost certainly far + // Do not include in mobility squares protected by enemy pawns or occupied by our pieces + const Bitboard mobilityArea = ~(ei.attackedBy[Them][PAWN] | pos.pieces(Us)); + + score += evaluate_pieces(pos, ei, mobility, mobilityArea); + score += evaluate_pieces(pos, ei, mobility, mobilityArea); + score += evaluate_pieces(pos, ei, mobility, mobilityArea); + score += evaluate_pieces(pos, ei, mobility, mobilityArea); + + // 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_king<>() assigns bonuses and penalties to a king of a given color + + template + Score evaluate_king(const Position& pos, EvalInfo& ei, Value margins[]) { + + const Color Them = (Us == WHITE ? BLACK : WHITE); + + Bitboard undefended, b, b1, b2, safe; + int attackUnits; + const Square ksq = pos.king_square(Us); + + // 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. - Color them = opposite_color(us); - if(p.queen_count(them) >= 1 && ei.attackCount[them] >= 2 - && p.non_pawn_material(them) >= QueenValueMidgame + RookValueMidgame - && ei.attacked[them]) { - - // Is it the attackers turn to move? - bool sente = (them == p.side_to_move()); - - // Find the attacked squares around the king which has no defenders - // apart from the king itself: - Bitboard undefended = - ei.attacked_by(them) & ~ei.attacked_by(us, PAWN) - & ~ei.attacked_by(us, KNIGHT) & ~ei.attacked_by(us, BISHOP) - & ~ei.attacked_by(us, ROOK) & ~ei.attacked_by(us, QUEEN) - & ei.attacked_by(us, KING); - Bitboard occ = p.occupied_squares(), b, b2; - - // Initialize the 'attackUnits' variable, which is used later on as an - // index to the SafetyTable[] array. The initial is based on the number - // and types of the attacking pieces, the number of attacked and - // undefended squares around the king, the square of the king, and the - // quality of the pawn shelter. - int attackUnits = - Min((ei.attackCount[them] * ei.attackWeight[them]) / 2, 25) - + (ei.attacked[them] + count_1s_max_15(undefended)) * 3 - + InitKingDanger[relative_square(us, s)] - shelter / 32; - - // Analyse safe queen contact checks: - b = undefended & ei.attacked_by(them, QUEEN) & ~p.pieces_of_color(them); - if(b) { - Bitboard attackedByOthers = - ei.attacked_by(them, PAWN) | ei.attacked_by(them, KNIGHT) - | ei.attacked_by(them, BISHOP) | ei.attacked_by(them, ROOK); - b &= attackedByOthers; - if(b) { - // The bitboard b now contains the squares available for safe queen - // contact checks. - int count = count_1s_max_15(b); - attackUnits += QueenContactCheckBonus * count * (sente? 2 : 1); - - // Is there a mate threat? - if(QueenContactMates && !p.is_check()) { - Bitboard escapeSquares = - p.king_attacks(s) & ~p.pieces_of_color(us) & ~attackedByOthers; - while(b) { - Square from, to = pop_1st_bit(&b); - if(!(escapeSquares - & ~queen_attacks_bb(to, occ & clear_mask_bb(s)))) { - // We have a mate, unless the queen is pinned or there - // is an X-ray attack through the queen. - for(int i = 0; i < p.queen_count(them); i++) { - from = p.queen_list(them, i); - if(bit_is_set(p.queen_attacks(from), to) - && !bit_is_set(p.pinned_pieces(them), from) - && !(rook_attacks_bb(to, occ & clear_mask_bb(from)) - & p.rooks_and_queens(us)) - && !(rook_attacks_bb(to, occ & clear_mask_bb(from)) - & p.rooks_and_queens(us))) - ei.mateThreat[them] = make_move(from, to); - } - } - } - } + if ( ei.kingAttackersCount[Them] >= 2 + && ei.kingAdjacentZoneAttacksCount[Them]) + { + // Find the attacked squares around the king which has no defenders + // apart from the king itself + undefended = ei.attackedBy[Them][0] & ei.attackedBy[Us][KING]; + undefended &= ~( 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 = std::min(25, (ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) / 2) + + 3 * (ei.kingAdjacentZoneAttacksCount[Them] + popcount(undefended)) + + InitKingDanger[relative_square(Us, ksq)] + - mg_value(score) / 32; + + // Analyse enemy's safe queen contact checks. First find undefended + // squares around the king attacked by enemy queen... + b = undefended & ei.attackedBy[Them][QUEEN] & ~pos.pieces(Them); + if (b) + { + // ...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 + * popcount(b) + * (Them == pos.side_to_move() ? 2 : 1); } - } - // Analyse safe rook contact checks: - if(RookContactCheckBonus) { - b = undefended & ei.attacked_by(them, ROOK) & ~p.pieces_of_color(them); - if(b) { - Bitboard attackedByOthers = - ei.attacked_by(them, PAWN) | ei.attacked_by(them, KNIGHT) - | ei.attacked_by(them, BISHOP) | ei.attacked_by(them, QUEEN); - b &= attackedByOthers; - if(b) { - int count = count_1s_max_15(b); - attackUnits += (RookContactCheckBonus * count * (sente? 2 : 1)); - } - } - } + // Analyse enemy's safe rook contact checks. First find undefended + // squares around the king attacked by enemy rooks... + b = undefended & ei.attackedBy[Them][ROOK] & ~pos.pieces(Them); - // Analyse safe distance checks: - if(QueenCheckBonus > 0 || RookCheckBonus > 0) { - b = p.rook_attacks(s) & ~p.pieces_of_color(them) & ~ei.attacked_by(us); + // Consider only squares where the enemy rook gives check + b &= PseudoAttacks[ROOK][ksq]; - // Queen checks - b2 = b & ei.attacked_by(them, QUEEN); - if(b2) attackUnits += QueenCheckBonus * count_1s_max_15(b2); + if (b) + { + // ...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 += RookContactCheckBonus + * popcount(b) + * (Them == pos.side_to_move() ? 2 : 1); + } - // Rook checks - b2 = b & ei.attacked_by(them, ROOK); - if(b2) attackUnits += RookCheckBonus * count_1s_max_15(b2); - } - if(QueenCheckBonus > 0 || BishopCheckBonus > 0) { - b = p.bishop_attacks(s) & ~p.pieces_of_color(them) & ~ei.attacked_by(us); - // Queen checks - b2 = b & ei.attacked_by(them, QUEEN); - if(b2) attackUnits += QueenCheckBonus * count_1s_max_15(b2); - - // Bishop checks - b2 = b & ei.attacked_by(them, BISHOP); - if(b2) attackUnits += BishopCheckBonus * count_1s_max_15(b2); - } - if(KnightCheckBonus > 0) { - b = p.knight_attacks(s) & ~p.pieces_of_color(them) & ~ei.attacked_by(us); - // Knight checks - b2 = b & ei.attacked_by(them, KNIGHT); - if(b2) attackUnits += KnightCheckBonus * count_1s_max_15(b2); - } + // Analyse enemy's safe distance checks for sliders and knights + safe = ~(pos.pieces(Them) | ei.attackedBy[Us][0]); + + b1 = pos.attacks_from(ksq) & safe; + b2 = pos.attacks_from(ksq) & safe; + + // Enemy queen safe checks + b = (b1 | b2) & ei.attackedBy[Them][QUEEN]; + if (b) + attackUnits += QueenCheckBonus * popcount(b); + + // Enemy rooks safe checks + b = b1 & ei.attackedBy[Them][ROOK]; + if (b) + attackUnits += RookCheckBonus * popcount(b); + + // Enemy bishops safe checks + b = b2 & ei.attackedBy[Them][BISHOP]; + if (b) + attackUnits += BishopCheckBonus * popcount(b); + + // Enemy knights safe checks + b = pos.attacks_from(ksq) & ei.attackedBy[Them][KNIGHT] & safe; + if (b) + attackUnits += KnightCheckBonus * popcount(b); + + // To index KingDangerTable[] attackUnits must be in [0, 99] range + attackUnits = std::min(99, std::max(0, attackUnits)); + + // Finally, extract the king danger score from the KingDangerTable[] + // array and subtract the score from evaluation. Set also margins[] + // 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. + score -= KingDangerTable[Us == Eval::RootColor][attackUnits]; + margins[Us] += mg_value(KingDangerTable[Us == Eval::RootColor][attackUnits]); + } - // Analyse discovered checks (only for non-pawns right now, consider - // adding pawns later). - if(DiscoveredCheckBonus) { - b = p.discovered_check_candidates(them) & ~p.pawns(); - if(b) - attackUnits += - DiscoveredCheckBonus * count_1s_max_15(b) * (sente? 2 : 1); - } + if (Trace) + TracedScores[Us][KING] = score; - // Has a mate threat been found? We don't do anything here if the - // side with the mating move is the side to move, because in that - // case the mating side will get a huge bonus at the end of the main - // evaluation function instead. - if(ei.mateThreat[them] != MOVE_NONE) - attackUnits += MateThreatBonus; - - // Ensure that attackUnits is between 0 and 99, in order to avoid array - // out of bounds errors: - if(attackUnits < 0) attackUnits = 0; - if(attackUnits >= 100) attackUnits = 99; - - // Finally, extract the king safety score from the SafetyTable[] array. - // Add the score to the evaluation, and also to ei.futilityMargin. The - // reason for adding the king safety score to the futility margin is - // that the king safety scores can sometimes be very big, and that - // capturing a single attacking piece can therefore result in a score - // change far bigger than the value of the captured piece. - Value v = apply_weight(SafetyTable[attackUnits], WeightKingSafety[us]); - ei.mgValue -= sign * v; - if(us == p.side_to_move()) - ei.futilityMargin += v; - } + return score; } - // evaluate_passed_pawns() evaluates the passed pawns for both sides. - - void evaluate_passed_pawns(const Position &pos, EvalInfo &ei) { - bool hasUnstoppable[2] = {false, false}; - int movesToGo[2] = {100, 100}; - - for(Color us = WHITE; us <= BLACK; us++) { - Color them = opposite_color(us); - Square ourKingSq = pos.king_square(us); - Square theirKingSq = pos.king_square(them); - Bitboard b = ei.pi->passed_pawns() & pos.pawns(us), b2, b3, b4; - - while(b) { - Square s = pop_1st_bit(&b); - assert(pos.piece_on(s) == pawn_of_color(us)); - assert(pos.pawn_is_passed(us, s)); - - int r = int(relative_rank(us, s) - RANK_2); - int tr = Max(0, r * (r-1)); - Square blockSq = s + pawn_push(us); - - // Base bonus based on rank: - Value mbonus = Value(20 * tr); - Value ebonus = Value(10 + r * r * 10); - - // Adjust bonus based on king proximity: - ebonus -= Value(square_distance(ourKingSq, blockSq) * 3 * tr); - ebonus -= - Value(square_distance(ourKingSq, blockSq + pawn_push(us)) * 1 * tr); - ebonus += Value(square_distance(theirKingSq, blockSq) * 6 * tr); - - // If the pawn is free to advance, increase bonus: - if(pos.square_is_empty(blockSq)) { - - b2 = squares_in_front_of(us, s); - b3 = b2 & ei.attacked_by(them); - b4 = b2 & ei.attacked_by(us); - if((b2 & pos.pieces_of_color(them)) == EmptyBoardBB) { - // There are no enemy pieces in the pawn's path! Are any of the - // squares in the pawn's path attacked by the enemy? - if(b3 == EmptyBoardBB) - // No enemy attacks, huge bonus! - ebonus += Value(tr * ((b2 == b4)? 17 : 15)); - else - // OK, there are enemy attacks. Are those squares which are - // attacked by the enemy also attacked by us? If yes, big bonus - // (but smaller than when there are no enemy attacks), if no, - // somewhat smaller bonus. - ebonus += Value(tr * (((b3 & b4) == b3)? 13 : 8)); - } - else { - // There are some enemy pieces in the pawn's path. While this is - // sad, we still assign a moderate bonus if all squares in the path - // which are either occupied by or attacked by enemy pieces are - // also attacked by us. - if(((b3 | (b2 & pos.pieces_of_color(them))) & ~b4) == EmptyBoardBB) - ebonus += Value(tr * 6); - } - // At last, add a small bonus when there are no *friendly* pieces - // in the pawn's path: - if((b2 & pos.pieces_of_color(us)) == EmptyBoardBB) - ebonus += Value(tr); - } + // evaluate_passed_pawns<>() evaluates the passed pawns of the given color + + template + Score evaluate_passed_pawns(const Position& pos, EvalInfo& ei) { - // If the pawn is supported by a friendly pawn, increase bonus. - b2 = pos.pawns(us) & neighboring_files_bb(s); - if(b2 & rank_bb(s)) - ebonus += Value(r * 20); - else if(pos.pawn_attacks(them, s) & b2) - ebonus += Value(r * 12); - - // If the other side has only a king, check whether the pawn is - // unstoppable: - if(pos.non_pawn_material(them) == Value(0)) { - Square qsq; - int d; - - qsq = relative_square(us, make_square(square_file(s), RANK_8)); - d = square_distance(s, qsq) - square_distance(theirKingSq, qsq) - + ((us == pos.side_to_move())? 0 : 1); - - if(d < 0) { - int mtg = RANK_8 - relative_rank(us, s); - int blockerCount = - count_1s_max_15(squares_in_front_of(us,s)&pos.occupied_squares()); - mtg += blockerCount; - d += blockerCount; - if(d < 0) { - hasUnstoppable[us] = true; - movesToGo[us] = Min(movesToGo[us], mtg); + const Color Them = (Us == WHITE ? BLACK : WHITE); + + Bitboard b, squaresToQueen, defendedSquares, unsafeSquares, supportingPawns; + Score score = SCORE_ZERO; + + b = ei.pi->passed_pawns(Us); + + if (!b) + return SCORE_ZERO; + + do { + Square s = pop_lsb(&b); + + assert(pos.pawn_is_passed(Us, s)); + + int r = int(relative_rank(Us, s) - RANK_2); + int rr = r * (r - 1); + + // Base bonus based on rank + Value mbonus = Value(20 * rr); + Value ebonus = Value(10 * (rr + r + 1)); + + if (rr) + { + Square blockSq = s + pawn_push(Us); + + // Adjust bonus based on kings proximity + ebonus += Value(square_distance(pos.king_square(Them), blockSq) * 5 * rr); + ebonus -= Value(square_distance(pos.king_square(Us), blockSq) * 2 * rr); + + // If blockSq is not the queening square then consider also a second push + if (rank_of(blockSq) != (Us == WHITE ? RANK_8 : RANK_1)) + ebonus -= Value(square_distance(pos.king_square(Us), blockSq + pawn_push(Us)) * rr); + + // If the pawn is free to advance, increase bonus + if (pos.is_empty(blockSq)) + { + squaresToQueen = forward_bb(Us, s); + defendedSquares = squaresToQueen & ei.attackedBy[Us][0]; + + // 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 ( (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.attackedBy[Them][0] | 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(rr * (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(rr * ((unsafeSquares & defendedSquares) == unsafeSquares ? 13 : 8)); } - } - } - // 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 + } // rr != 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(Us, PAWN) & adjacent_files_bb(file_of(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 - && pos.knight_count(them) == 1) - ebonus += ebonus / 4; - else if(pos.rooks_and_queens(them)) - ebonus -= ebonus / 4; + if (file_of(s) == FILE_A || file_of(s) == FILE_H) + { + if (pos.non_pawn_material(Them) <= KnightValueMg) + ebonus += ebonus / 4; + else if (pos.pieces(Them, ROOK, QUEEN)) + ebonus -= ebonus / 4; } + score += make_score(mbonus, ebonus); - // Add the scores for this pawn to the middle game and endgame eval. - ei.mgValue += apply_weight(Sign[us] * mbonus, WeightPassedPawnsMidgame); - ei.egValue += apply_weight(Sign[us] * ebonus, WeightPassedPawnsEndgame); - } - } + } while (b); - // Does either side have an unstoppable passed pawn? - if(hasUnstoppable[WHITE] && !hasUnstoppable[BLACK]) - ei.egValue += UnstoppablePawnValue - Value(0x40 * movesToGo[WHITE]); - else if(hasUnstoppable[BLACK] && !hasUnstoppable[WHITE]) - ei.egValue -= UnstoppablePawnValue - Value(0x40 * movesToGo[BLACK]); - else if(hasUnstoppable[BLACK] && hasUnstoppable[WHITE]) { - // Both sides have unstoppable pawns! Try to find out who queens - // first. We begin by transforming 'movesToGo' to the number of - // plies until the pawn queens for both sides: - movesToGo[WHITE] *= 2; - movesToGo[BLACK] *= 2; - movesToGo[pos.side_to_move()]--; - - // If one side queens at least three plies before the other, that - // side wins: - if(movesToGo[WHITE] <= movesToGo[BLACK] - 3) - ei.egValue += UnstoppablePawnValue - Value(0x40 * (movesToGo[WHITE]/2)); - else if(movesToGo[BLACK] <= movesToGo[WHITE] - 3) - ei.egValue -= UnstoppablePawnValue - Value(0x40 * (movesToGo[BLACK]/2)); - - // We could also add some rules about the situation when one side - // queens exactly one ply before the other: Does the first queen - // check the opponent's king, or attack the opponent's queening square? - // This is slightly tricky to get right, because it is possible that - // the opponent's king has moved somewhere before the first pawn queens. - } + // Add the scores to the middle game and endgame eval + return apply_weight(score, Weights[PassedPawns]); } - // 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. + // evaluate_unstoppable_pawns() evaluates the unstoppable passed pawns for both sides, this is quite + // conservative and returns a winning score only when we are very sure that the pawn is winning. - void evaluate_trapped_bishop_a7h7(const Position &pos, Square s, Color us, - EvalInfo &ei) { - Piece pawn = pawn_of_color(opposite_color(us)); - Square b6, b8; + Score evaluate_unstoppable_pawns(const Position& pos, EvalInfo& ei) { - assert(square_is_ok(s)); - assert(pos.piece_on(s) == bishop_of_color(us)); + Bitboard b, b2, blockers, supporters, queeningPath, candidates; + Square s, blockSq, queeningSquare; + Color c, winnerSide, loserSide; + bool pathDefended, opposed; + int pliesToGo, movesToGo, oppMovesToGo, sacptg, blockersCount, minKingDist, kingptg, d; + int pliesToQueen[] = { 256, 256 }; - if(square_file(s) == FILE_A) { - b6 = relative_square(us, SQ_B6); - b8 = relative_square(us, SQ_B8); - } - else { - b6 = relative_square(us, SQ_G6); - b8 = relative_square(us, SQ_G8); - } + // Step 1. Hunt for unstoppable passed pawns. If we find at least one, + // record how many plies are required for promotion. + for (c = WHITE; c <= BLACK; c++) + { + // Skip if other side has non-pawn pieces + if (pos.non_pawn_material(~c)) + continue; - if(pos.piece_on(b6) == pawn && pos.see(s, b6) < 0 && pos.see(s, b8) < 0) { - ei.mgValue -= Sign[us] * TrappedBishopA7H7Penalty; - ei.egValue -= Sign[us] * TrappedBishopA7H7Penalty; - } + b = ei.pi->passed_pawns(c); - } + while (b) + { + s = pop_lsb(&b); + queeningSquare = relative_square(c, file_of(s) | RANK_8); + queeningPath = forward_bb(c, s); + + // Compute plies to queening and check direct advancement + movesToGo = rank_distance(s, queeningSquare) - int(relative_rank(c, s) == RANK_2); + oppMovesToGo = square_distance(pos.king_square(~c), queeningSquare) - int(c != pos.side_to_move()); + pathDefended = ((ei.attackedBy[c][0] & queeningPath) == queeningPath); + if (movesToGo >= oppMovesToGo && !pathDefended) + continue; - // 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. + // Opponent king cannot block because path is defended and position + // is not in check. So only friendly pieces can be blockers. + assert(!pos.in_check()); + assert((queeningPath & pos.pieces()) == (queeningPath & pos.pieces(c))); - void evaluate_trapped_bishop_a1h1(const Position &pos, Square s, Color us, - EvalInfo &ei) { - Piece pawn = pawn_of_color(us); - Square b2, b3, c3; + // Add moves needed to free the path from friendly pieces and retest condition + movesToGo += popcount(queeningPath & pos.pieces(c)); - assert(Chess960); - assert(square_is_ok(s)); - assert(pos.piece_on(s) == bishop_of_color(us)); + if (movesToGo >= oppMovesToGo && !pathDefended) + continue; - if(square_file(s) == FILE_A) { - b2 = relative_square(us, SQ_B2); - b3 = relative_square(us, SQ_B3); - c3 = relative_square(us, SQ_C3); + pliesToGo = 2 * movesToGo - int(c == pos.side_to_move()); + pliesToQueen[c] = std::min(pliesToQueen[c], pliesToGo); + } } - else { - b2 = relative_square(us, SQ_G2); - b3 = relative_square(us, SQ_G3); - c3 = relative_square(us, SQ_F3); + + // Step 2. If either side cannot promote at least three plies before the other side then situation + // becomes too complex and we give up. Otherwise we determine the possibly "winning side" + if (abs(pliesToQueen[WHITE] - pliesToQueen[BLACK]) < 3) + return SCORE_ZERO; + + winnerSide = (pliesToQueen[WHITE] < pliesToQueen[BLACK] ? WHITE : BLACK); + loserSide = ~winnerSide; + + // Step 3. Can the losing side possibly create a new passed pawn and thus prevent the loss? + b = candidates = pos.pieces(loserSide, PAWN); + + while (b) + { + s = pop_lsb(&b); + + // Compute plies from queening + queeningSquare = relative_square(loserSide, file_of(s) | RANK_8); + movesToGo = rank_distance(s, queeningSquare) - int(relative_rank(loserSide, s) == RANK_2); + pliesToGo = 2 * movesToGo - int(loserSide == pos.side_to_move()); + + // Check if (without even considering any obstacles) we're too far away or doubled + if ( pliesToQueen[winnerSide] + 3 <= pliesToGo + || (forward_bb(loserSide, s) & pos.pieces(loserSide, PAWN))) + candidates ^= s; } - if(pos.piece_on(b2) == pawn) { - Value penalty; + // If any candidate is already a passed pawn it _may_ promote in time. We give up. + if (candidates & ei.pi->passed_pawns(loserSide)) + return SCORE_ZERO; - if(!pos.square_is_empty(b3)) - penalty = 2*TrappedBishopA1H1Penalty; - else if(pos.piece_on(c3) == pawn) - penalty = TrappedBishopA1H1Penalty; - else - penalty = TrappedBishopA1H1Penalty / 2; + // Step 4. Check new passed pawn creation through king capturing and pawn sacrifices + b = candidates; + + while (b) + { + s = pop_lsb(&b); + sacptg = blockersCount = 0; + minKingDist = kingptg = 256; + + // Compute plies from queening + queeningSquare = relative_square(loserSide, file_of(s) | RANK_8); + movesToGo = rank_distance(s, queeningSquare) - int(relative_rank(loserSide, s) == RANK_2); + pliesToGo = 2 * movesToGo - int(loserSide == pos.side_to_move()); + + // Generate list of blocking pawns and supporters + supporters = adjacent_files_bb(file_of(s)) & candidates; + opposed = forward_bb(loserSide, s) & pos.pieces(winnerSide, PAWN); + blockers = passed_pawn_mask(loserSide, s) & pos.pieces(winnerSide, PAWN); - ei.mgValue -= Sign[us] * penalty; - ei.egValue -= Sign[us] * penalty; + assert(blockers); + + // How many plies does it take to remove all the blocking pawns? + while (blockers) + { + blockSq = pop_lsb(&blockers); + movesToGo = 256; + + // Check pawns that can give support to overcome obstacle, for instance + // black pawns: a4, b4 white: b2 then pawn in b4 is giving support. + if (!opposed) + { + b2 = supporters & in_front_bb(winnerSide, blockSq + pawn_push(winnerSide)); + + while (b2) // This while-loop could be replaced with LSB/MSB (depending on color) + { + d = square_distance(blockSq, pop_lsb(&b2)) - 2; + movesToGo = std::min(movesToGo, d); + } + } + + // Check pawns that can be sacrificed against the blocking pawn + b2 = attack_span_mask(winnerSide, blockSq) & candidates & ~(1ULL << s); + + while (b2) // This while-loop could be replaced with LSB/MSB (depending on color) + { + d = square_distance(blockSq, pop_lsb(&b2)) - 2; + movesToGo = std::min(movesToGo, d); + } + + // If obstacle can be destroyed with an immediate pawn exchange / sacrifice, + // it's not a real obstacle and we have nothing to add to pliesToGo. + if (movesToGo <= 0) + continue; + + // Plies needed to sacrifice against all the blocking pawns + sacptg += movesToGo * 2; + blockersCount++; + + // Plies needed for the king to capture all the blocking pawns + d = square_distance(pos.king_square(loserSide), blockSq); + minKingDist = std::min(minKingDist, d); + kingptg = (minKingDist + blockersCount) * 2; + } + + // Check if pawn sacrifice plan _may_ save the day + if (pliesToQueen[winnerSide] + 3 > pliesToGo + sacptg) + return SCORE_ZERO; + + // Check if king capture plan _may_ save the day (contains some false positives) + if (pliesToQueen[winnerSide] + 3 > pliesToGo + kingptg) + return SCORE_ZERO; } + // Winning pawn is unstoppable and will promote as first, return big score + Score score = make_score(0, (Value) 1280 - 32 * pliesToQueen[winnerSide]); + return winnerSide == WHITE ? score : -score; } - // apply_weight applies an evaluation weight to a value. + // evaluate_space() computes the space evaluation for a given side. The + // space evaluation is a simple bonus based on the number of safe squares + // available for minor pieces on the central four files on ranks 2--4. Safe + // squares one, two or three squares behind a friendly pawn are counted + // twice. Finally, the space bonus is scaled by a weight taken from the + // material hash table. The aim is to improve play on game opening. + template + int evaluate_space(const Position& pos, EvalInfo& ei) { + + const Color Them = (Us == WHITE ? BLACK : WHITE); + + // Find the safe squares for our pieces inside the area defined by + // SpaceMask[]. A square is unsafe if it is attacked by an enemy + // pawn, or if it is undefended and attacked by an enemy piece. + Bitboard safe = SpaceMask[Us] + & ~pos.pieces(Us, PAWN) + & ~ei.attackedBy[Them][PAWN] + & (ei.attackedBy[Us][0] | ~ei.attackedBy[Them][0]); - inline Value apply_weight(Value v, int w) { - return (v*w) / 0x100; + // Find all squares which are at most three squares behind some friendly pawn + Bitboard behind = pos.pieces(Us, PAWN); + behind |= (Us == WHITE ? behind >> 8 : behind << 8); + behind |= (Us == WHITE ? behind >> 16 : behind << 16); + + return popcount(safe) + popcount(behind & safe); } - // 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. + // interpolate() interpolates between a middle game and an endgame score, + // based on game phase. It also scales the return value by a ScaleFactor array. + + Value interpolate(const Score& v, Phase ph, ScaleFactor sf) { - Value scale_by_game_phase(Value mv, Value ev, Phase ph, ScaleFactor sf[]) { - assert(mv > -VALUE_INFINITE && mv < VALUE_INFINITE); - assert(ev > -VALUE_INFINITE && ev < VALUE_INFINITE); + assert(mg_value(v) > -VALUE_INFINITE && mg_value(v) < VALUE_INFINITE); + assert(eg_value(v) > -VALUE_INFINITE && eg_value(v) < VALUE_INFINITE); assert(ph >= PHASE_ENDGAME && ph <= PHASE_MIDGAME); - if(ev > Value(0)) - ev = apply_scale_factor(ev, sf[WHITE]); - else - ev = apply_scale_factor(ev, sf[BLACK]); + int ev = (eg_value(v) * int(sf)) / SCALE_FACTOR_NORMAL; + int result = (mg_value(v) * int(ph) + ev * int(128 - ph)) / 128; + return Value((result + GrainSize / 2) & ~(GrainSize - 1)); + } - // Superlinear interpolator - int sli_ph = int(ph); - sli_ph -= (64 - sli_ph) / 4; - sli_ph = Min(PHASE_MIDGAME, Max(PHASE_ENDGAME, sli_ph)); // ceiling - Value result = Value(int((mv * sli_ph + ev * (128 - sli_ph)) / 128)); - return Value(int(result) & ~(GrainSize - 1)); - } + // 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) { - // count_1s_8bit() counts the number of nonzero bits in the 8 least - // significant bits of a Bitboard. This function is used by the king - // shield evaluation. + // Scale option value from 100 to 256 + int mg = Options[mgOpt] * 256 / 100; + int eg = Options[egOpt] * 256 / 100; - int count_1s_8bit(Bitboard b) { - return int(BitCount8Bit[b & 0xFF]); + return apply_weight(make_score(mg, eg), internalWeight); } - // compute_weight() computes the value of an evaluation weight, by combining - // an UCI-configurable weight with an internal weight. + // A couple of little helpers used by tracing code, to_cp() converts a value to + // a double in centipawns scale, trace_add() stores white and black scores. + + double to_cp(Value v) { return double(v) / double(PawnValueMg); } + + void trace_add(int idx, Score wScore, Score bScore) { - int compute_weight(int uciWeight, int internalWeight) { - uciWeight = (uciWeight * 0x100) / 100; - return (uciWeight * internalWeight) / 0x100; + TracedScores[WHITE][idx] = wScore; + TracedScores[BLACK][idx] = bScore; } - // init_safety() initizes the king safety evaluation, based on UCI - // parameters. It is called from read_weights(). - - void init_safety() { - double a, b; - int maxSlope, peak, i, j; - - QueenContactCheckBonus = get_option_value_int("Queen Contact Check Bonus"); - RookContactCheckBonus = get_option_value_int("Rook Contact Check Bonus"); - QueenCheckBonus = get_option_value_int("Queen Check Bonus"); - RookCheckBonus = get_option_value_int("Rook Check Bonus"); - BishopCheckBonus = get_option_value_int("Bishop Check Bonus"); - KnightCheckBonus = get_option_value_int("Knight Check Bonus"); - DiscoveredCheckBonus = get_option_value_int("Discovered Check Bonus"); - MateThreatBonus = get_option_value_int("Mate Threat Bonus"); - - a = get_option_value_int("King Safety Coefficient") / 100.0; - b = get_option_value_int("King Safety X Intercept") * 1.0; - maxSlope = get_option_value_int("King Safety Max Slope"); - peak = (get_option_value_int("King Safety Max Value") * 256) / 100; - - for(i = 0; i < 100; i++) { - if(i < b) SafetyTable[i] = Value(0); - else if(get_option_value_string("King Safety Curve") == "Quadratic") - SafetyTable[i] = Value((int)(a * (i - b) * (i - b))); - else if(get_option_value_string("King Safety Curve") == "Linear") - SafetyTable[i] = Value((int)(100 * a * (i - b))); + // trace_row() is an helper function used by tracing code to register the + // values of a single evaluation term. + + void trace_row(const char* name, int idx) { + + Score wScore = TracedScores[WHITE][idx]; + Score bScore = TracedScores[BLACK][idx]; + + switch (idx) { + case PST: case IMBALANCE: case PAWN: case UNSTOPPABLE: case TOTAL: + TraceStream << std::setw(20) << name << " | --- --- | --- --- | " + << std::setw(6) << to_cp(mg_value(wScore)) << " " + << std::setw(6) << to_cp(eg_value(wScore)) << " \n"; + break; + default: + TraceStream << std::setw(20) << 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::showpos + << std::setw(6) << to_cp(mg_value(wScore - bScore)) << " " + << std::setw(6) << to_cp(eg_value(wScore - bScore)) << " \n"; } - - for(i = 0; i < 100; i++) - if(SafetyTable[i+1] - SafetyTable[i] > maxSlope) { - for(j = i + 1; j < 100; j++) - SafetyTable[j] = SafetyTable[j-1] + Value(maxSlope); - } - for(i = 0; i < 100; i++) - if(SafetyTable[i] > Value(peak)) - SafetyTable[i] = Value(peak); } - }