/*
- 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.
-
+
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
-
-////
-//// Includes
-////
-
#include <cassert>
-#include <cstring>
+#include <iomanip>
+#include <sstream>
+#include <algorithm>
+#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 = 8;
- // Evaluation grain size, must be a power of 2.
- const int GrainSize = 4;
+ // Evaluation weights, initialized from UCI options
+ enum { Mobility, PassedPawns, Space, KingDangerUs, KingDangerThem };
+ Score Weights[6];
- // 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 };
+ typedef Value V;
+ #define S(mg, eg) make_score(mg, eg)
- // Internal evaluation weights. These are applied on top of the evaluation
- // weights read from UCI parameters. The purpose is to be able to change
+ // 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;
-
- // Knight mobility bonus in middle game and endgame, indexed by the number
- // of attacked squares not occupied by friendly piecess.
- const Value MidgameKnightMobilityBonus[] = {
- Value(-30), Value(-20), Value(-10), Value(0), Value(10),
- Value(20), Value(25), Value(30), Value(30)
- };
-
- const Value EndgameKnightMobilityBonus[] = {
- Value(-30), Value(-20), Value(-10), Value(0), Value(10),
- Value(20), Value(25), Value(30), Value(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[] = {
- Value(-30), Value(-15), Value(0), Value(15), Value(30), Value(45),
- Value(58), Value(66), Value(72), Value(76), Value(78), Value(80),
- Value(81), Value(82), Value(83), Value(83)
+ //
+ // Values modified by Joona Kiiski
+ const Score WeightsInternal[] = {
+ S(252, 344), S(216, 266), S(46, 0), S(247, 0), S(259, 0)
};
- const Value EndgameBishopMobilityBonus[] = {
- Value(-30), Value(-15), Value(0), Value(15), Value(30), Value(45),
- Value(58), Value(66), Value(72), Value(76), Value(78), Value(80),
- Value(81), Value(82), Value(83), Value(83)
+ // 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) }
};
- // 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[] = {
- Value(-18), Value(-12), Value(-6), Value(0), Value(6), Value(12),
- Value(16), Value(21), Value(24), Value(27), Value(28), Value(29),
- Value(30), Value(31), Value(32), Value(33)
- };
-
- const Value EndgameRookMobilityBonus[] = {
- Value(-30), Value(-18), Value(-6), Value(6), Value(18), Value(30),
- Value(42), Value(54), Value(66), Value(74), Value(78), Value(80),
- Value(81), Value(82), Value(83), Value(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[] = {
- Value(-10), Value(-8), Value(-6), Value(-4), Value(-2), Value(0), Value(2),
- Value(4), Value(6), Value(8), Value(10), Value(12), Value(13), Value(14),
- Value(15), Value(16), Value(16), Value(16), Value(16), Value(16),
- Value(16), Value(16), Value(16), Value(16), Value(16), Value(16),
- Value(16), Value(16), Value(16), Value(16), Value(16), Value(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[] = {
- Value(-20), Value(-15), Value(-10), Value(-5), Value(0), Value(5),
- Value(10), Value(15), Value(19), Value(23), Value(27), Value(29),
- Value(30), Value(30), Value(30), Value(30), Value(30), Value(30),
- Value(30), Value(30), Value(30), Value(30), Value(30), Value(30),
- Value(30), Value(30), Value(30), Value(30), Value(30), Value(30),
- Value(30), Value(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)
};
+ #undef S
- // Outpost bonuses for knights and bishops, indexed by square (from white's
- // point of view).
- const Value KnightOutpostBonus[64] = {
- Value(0),Value(0),Value(0),Value(0),Value(0),Value(0),Value(0),Value(0),
- Value(0),Value(0),Value(0),Value(0),Value(0),Value(0),Value(0),Value(0),
- Value(0),Value(0),Value(5),Value(10),Value(10),Value(5),Value(0),Value(0),
- Value(0),Value(5),Value(20),Value(30),Value(30),Value(20),Value(5),Value(0),
- Value(0),Value(10),Value(30),Value(40),Value(40),Value(30),Value(10),Value(0),
- Value(0),Value(5),Value(20),Value(20),Value(20),Value(20),Value(5),Value(0),
- Value(0),Value(0),Value(0),Value(0),Value(0),Value(0),Value(0),Value(0),
- Value(0),Value(0),Value(0),Value(0),Value(0),Value(0),Value(0),Value(0)
- };
-
- const Value BishopOutpostBonus[64] = {
- Value(0),Value(0),Value(0),Value(0),Value(0),Value(0),Value(0),Value(0),
- Value(0),Value(0),Value(0),Value(0),Value(0),Value(0),Value(0),Value(0),
- Value(0),Value(0),Value(5),Value(5),Value(5),Value(5),Value(0),Value(0),
- Value(0),Value(5),Value(10),Value(10),Value(10),Value(10),Value(5),Value(0),
- Value(0),Value(10),Value(20),Value(20),Value(20),Value(20),Value(10),Value(0),
- Value(0),Value(5),Value(8),Value(8),Value(8),Value(8),Value(5),Value(0),
- Value(0),Value(0),Value(0),Value(0),Value(0),Value(0),Value(0),Value(0),
- Value(0),Value(0),Value(0),Value(0),Value(0),Value(0),Value(0),Value(0)
- };
+ // 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] = {
- 2, 0, 2, 5, 5, 2, 0, 2,
- 2, 2, 4, 8, 8, 4, 2, 2,
- 7, 10, 12, 12, 12, 12, 10, 7,
+ // 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,
15, 15, 15, 15, 15, 15, 15, 15,
15, 15, 15, 15, 15, 15, 15, 15,
15, 15, 15, 15, 15, 15, 15, 15,
15, 15, 15, 15, 15, 15, 15, 15,
+ 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<bool Trace>
+ Value do_evaluate(const Position& pos, Value& margin);
- // Sizes of pawn and material hash tables:
- const int PawnTableSize = 16384;
- const int MaterialTableSize = 1024;
+ template<Color Us>
+ 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<Color Us, bool Trace>
+ 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<Color Us, bool Trace>
+ 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<Color Us>
+ Score evaluate_threats(const Position& pos, EvalInfo& ei);
- Value apply_weight(Value v, int w);
- Value scale_by_game_phase(Value mv, Value ev, Phase ph, ScaleFactor sf[]);
+ template<Color Us>
+ int evaluate_space(const Position& pos, EvalInfo& ei);
- int count_1s_8bit(Bitboard b);
+ template<Color Us>
+ 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<false>(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);
- }
-
- // Bishops
- for(int i = 0; i < pos.bishop_count(c); i++) {
- s = pos.bishop_list(c, i);
- evaluate_bishop(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));
- // Rooks
- for(int i = 0; i < pos.rook_count(c); i++) {
- s = pos.rook_list(c, i);
- evaluate_rook(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]);
}
+ }
- // Queens
- for(int i = 0; i < pos.queen_count(c); i++) {
- s = pos.queen_list(c, i);
- evaluate_queen(pos, s, c, ei);
- }
- // Some special patterns:
+ /// 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.
- // 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);
- }
+ std::string trace(const Position& pos) {
- // 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);
- }
- }
+ Value margin;
+ std::string totals;
- 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];
- }
+ RootColor = pos.side_to_move();
- // 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);
- }
+ TraceStream.str("");
+ TraceStream << std::showpoint << std::showpos << std::fixed << std::setprecision(2);
+ memset(TracedScores, 0, 2 * 16 * sizeof(Score));
+
+ do_evaluate<true>(pos, margin);
+
+ totals = TraceStream.str();
+ TraceStream.str("");
- // 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);
+ TraceStream << std::setw(21) << "Eval term " << "| White | Black | Total \n"
+ << " | MG EG | MG EG | MG EG \n"
+ << "---------------------+-------------+-------------+---------------\n";
+
+ 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();
}
- // Mobility
- ei.mgValue += apply_weight(ei.mgMobility, WeightMobilityMidgame);
- ei.egValue += apply_weight(ei.egMobility, WeightMobilityEndgame);
+} // namespace Eval
- // 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);
- }
+
+namespace {
+
+template<bool Trace>
+Value do_evaluate(const Position& pos, Value& margin) {
+
+ assert(!pos.in_check());
+
+ EvalInfo ei;
+ Value margins[2];
+ Score score, mobilityWhite, mobilityBlack;
+
+ // 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;
+
+ // 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);
+
+ // Probe the material hash table
+ ei.mi = pos.this_thread()->materialTable.probe(pos);
+ score += ei.mi->material_value();
+
+ // If we have a specialized evaluation function for the current material
+ // configuration, call it and return.
+ if (ei.mi->specialized_eval_exists())
+ {
+ margin = VALUE_ZERO;
+ return ei.mi->evaluate(pos);
}
- // Interpolate between the middle game and the endgame score, and
- // return:
- Value value = scale_by_game_phase(ei.mgValue, ei.egValue, phase, factor);
+ // Probe the pawn hash table
+ ei.pi = pos.this_thread()->pawnTable.probe(pos);
+ score += ei.pi->pawns_value();
- if(ei.mateThreat[stm] != MOVE_NONE)
- return 8 * QueenValueMidgame - Sign[stm] * value;
- else
- return Sign[stm] * value;
-}
+ // Initialize attack and king safety bitboards
+ init_eval_info<WHITE>(pos, ei);
+ init_eval_info<BLACK>(pos, ei);
+ // Evaluate pieces and mobility
+ score += evaluate_pieces_of_color<WHITE, Trace>(pos, ei, mobilityWhite)
+ - evaluate_pieces_of_color<BLACK, Trace>(pos, ei, mobilityBlack);
-/// 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?
+ score += apply_weight(mobilityWhite - mobilityBlack, Weights[Mobility]);
-Value quick_evaluate(const Position &pos) {
- Color stm;
- Value mgValue, egValue;
- ScaleFactor factor[2] = {SCALE_FACTOR_NORMAL, SCALE_FACTOR_NORMAL};
- Phase phase;
-
- assert(pos.is_ok());
+ // Evaluate kings after all other pieces because we need complete attack
+ // information when computing the king safety evaluation.
+ score += evaluate_king<WHITE, Trace>(pos, ei, margins)
+ - evaluate_king<BLACK, Trace>(pos, ei, margins);
- stm = pos.side_to_move();
+ // Evaluate tactical threats, we need full attack information including king
+ score += evaluate_threats<WHITE>(pos, ei)
+ - evaluate_threats<BLACK>(pos, ei);
- mgValue = pos.mg_value();
- egValue = pos.eg_value();
- phase = pos.game_phase();
+ // Evaluate passed pawns, we need full attack information including king
+ score += evaluate_passed_pawns<WHITE>(pos, ei)
+ - evaluate_passed_pawns<BLACK>(pos, ei);
- Value value = scale_by_game_phase(mgValue, egValue, phase, factor);
+ // 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);
- return Sign[stm] * value;
-}
-
-
-/// init_eval() initializes various tables used by the evaluation function.
-
-void init_eval(int threads) {
- assert(threads <= THREAD_MAX);
-
- for(int i = 0; i < threads; i++) {
- if(PawnTable[i] == NULL)
- PawnTable[i] = new PawnInfoTable(PawnTableSize);
- if(MaterialTable[i] == NULL)
- MaterialTable[i] = new MaterialInfoTable(MaterialTableSize);
+ // Evaluate space for both sides, only in middle-game.
+ if (ei.mi->space_weight())
+ {
+ int s = evaluate_space<WHITE>(pos, ei) - evaluate_space<BLACK>(pos, ei);
+ score += apply_weight(make_score(s * ei.mi->space_weight(), 0), Weights[Space]);
}
- for(int i = threads; i < THREAD_MAX; i++) {
- if(PawnTable[i] != NULL) {
- delete PawnTable[i];
- PawnTable[i] = NULL;
- }
- if(MaterialTable[i] != NULL) {
- delete MaterialTable[i];
- MaterialTable[i] = NULL;
- }
+
+ // 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);
}
- for(Bitboard b = 0ULL; b < 256ULL; b++)
- BitCount8Bit[b] = count_1s(b);
+ margin = margins[pos.side_to_move()];
+ Value v = interpolate(score, ei.mi->game_phase(), sf);
+
+ // 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<WHITE>(pos, ei), evaluate_threats<BLACK>(pos, ei));
+ trace_add(PASSED, evaluate_passed_pawns<WHITE>(pos, ei), evaluate_passed_pawns<BLACK>(pos, ei));
+ trace_add(UNSTOPPABLE, evaluate_unstoppable_pawns(pos, ei));
+ Score w = make_score(ei.mi->space_weight() * evaluate_space<WHITE>(pos, ei), 0);
+ Score b = make_score(ei.mi->space_weight() * evaluate_space<BLACK>(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);
+ }
+
+ return pos.side_to_move() == WHITE ? v : -v;
}
-/// quit_eval() releases heap-allocated memory at program termination.
+ // init_eval_info() initializes king bitboards for given color adding
+ // pawn attacks. To be done at the beginning of the evaluation.
+
+ template<Color Us>
+ void init_eval_info(const Position& pos, EvalInfo& ei) {
-void quit_eval() {
- for(int i = 0; i < THREAD_MAX; i++) {
- delete PawnTable[i];
- delete MaterialTable[i];
+ const Color Them = (Us == WHITE ? BLACK : WHITE);
+
+ Bitboard b = ei.attackedBy[Them][KING] = pos.attacks_from<KING>(pos.king_square(Them));
+ ei.attackedBy[Us][PAWN] = ei.pi->pawn_attacks(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.kingRing[Them] = (b | (Us == WHITE ? b >> 8 : b << 8));
+ b &= ei.attackedBy[Us][PAWN];
+ ei.kingAttackersCount[Us] = b ? popcount<Max15>(b) / 2 : 0;
+ ei.kingAdjacentZoneAttacksCount[Us] = ei.kingAttackersWeight[Us] = 0;
+ } else
+ ei.kingRing[Them] = ei.kingAttackersCount[Us] = 0;
}
-}
-/// 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();
-}
+ // evaluate_outposts() evaluates bishop and knight outposts squares
+ template<PieceType Piece, Color Us>
+ Score evaluate_outposts(const Position& pos, EvalInfo& ei, Square s) {
-namespace {
+ const Color Them = (Us == WHITE ? BLACK : WHITE);
- // evaluate_knight() assigns bonuses and penalties to a knight of a given
- // color on a given square.
-
- void evaluate_knight(const Position &p, Square s, Color us, EvalInfo &ei) {
-
- Color them = opposite_color(us);
- Bitboard b = p.knight_attacks(s);
- ei.attackedBy[us][KNIGHT] |= b;
-
- // King attack
- if(b & ei.attackZone[us]) {
- ei.attackCount[us]++;
- ei.attackWeight[us] += KnightAttackWeight;
- Bitboard bb = (b & ei.attackedBy[them][KING]);
- if(bb) ei.attacked[us] += count_1s_max_15(bb);
- }
-
- // Mobility
- int mob = count_1s_max_15(b & ~p.pieces_of_color(us));
- ei.mgMobility += Sign[us] * MidgameKnightMobilityBonus[mob];
- ei.egMobility += Sign[us] * EndgameKnightMobilityBonus[mob];
-
- // Knight outposts:
- if(p.square_is_weak(s, them)) {
- Value v, bonus;
-
- // Initial bonus based on square:
- v = bonus = KnightOutpostBonus[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)) {
- bonus += v/2;
- if(p.knight_count(them) == 0 &&
- (SquaresByColorBB[square_color(s)] &
- p.bishops(them)) == EmptyBoardBB) {
- bonus += v;
- }
- }
+ assert (Piece == BISHOP || Piece == KNIGHT);
+
+ // Initial bonus based on square
+ Value bonus = OutpostBonus[Piece == BISHOP][relative_square(Us, s)];
- ei.mgValue += Sign[us] * bonus;
- ei.egValue += Sign[us] * bonus;
+ // Increase bonus if supported by pawn, especially if the opponent has
+ // no minor piece which can exchange the outpost piece.
+ if (bonus && (ei.attackedBy[Us][PAWN] & s))
+ {
+ if ( !pos.pieces(Them, KNIGHT)
+ && !(same_color_squares(s) & pos.pieces(Them, BISHOP)))
+ bonus += bonus + bonus / 2;
+ else
+ bonus += bonus / 2;
}
+ return make_score(bonus, bonus);
}
- // evaluate_bishop() assigns bonuses and penalties to a bishop of a given
- // color on a given square.
-
- void evaluate_bishop(const Position &p, Square s, Color us, EvalInfo &ei) {
+ // evaluate_pieces<>() assigns bonuses and penalties to the pieces of a given color
- Color them = opposite_color(us);
- Bitboard b =
- bishop_attacks_bb(s, p.occupied_squares() & ~p.queens(us));
-
- ei.attackedBy[us][BISHOP] |= b;
+ template<PieceType Piece, Color Us, bool Trace>
+ Score evaluate_pieces(const Position& pos, EvalInfo& ei, Score& mobility, Bitboard mobilityArea) {
- // King attack
- if(b & ei.attackZone[us]) {
- ei.attackCount[us]++;
- ei.attackWeight[us] += BishopAttackWeight;
- Bitboard bb = (b & ei.attackedBy[them][KING]);
- if(bb) ei.attacked[us] += count_1s_max_15(bb);
- }
-
- // Mobility:
- int mob = count_1s_max_15(b & ~p.pieces_of_color(us));
- ei.mgMobility += Sign[us] * MidgameBishopMobilityBonus[mob];
- ei.egMobility += Sign[us] * EndgameBishopMobilityBonus[mob];
-
- // Bishop outposts:
- if(p.square_is_weak(s, them)) {
- Value v, bonus;
-
- // Initial bonus based on square:
- v = bonus = BishopOutpostBonus[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)) {
- bonus += v/2;
- if(p.knight_count(them) == 0 &&
- (SquaresByColorBB[square_color(s)] &
- p.bishops(them)) == EmptyBoardBB) {
- bonus += v;
+ Bitboard b;
+ Square s, ksq;
+ int mob;
+ File f;
+ Score score = SCORE_ZERO;
+
+ const Color Them = (Us == WHITE ? BLACK : WHITE);
+ const Square* pl = pos.piece_list(Us, Piece);
+
+ ei.attackedBy[Us][Piece] = 0;
+
+ while ((s = *pl++) != SQ_NONE)
+ {
+ // Find attacked squares, including x-ray attacks for bishops and rooks
+ if (Piece == KNIGHT || Piece == QUEEN)
+ b = pos.attacks_from<Piece>(s);
+ else if (Piece == BISHOP)
+ b = attacks_bb<BISHOP>(s, pos.pieces() ^ pos.pieces(Us, QUEEN));
+ else if (Piece == ROOK)
+ b = attacks_bb<ROOK>(s, pos.pieces() ^ pos.pieces(Us, ROOK, QUEEN));
+ else
+ assert(false);
+
+ ei.attackedBy[Us][Piece] |= 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<Max15>(bb);
}
- }
- ei.mgValue += Sign[us] * bonus;
- ei.egValue += Sign[us] * bonus;
- }
- }
-
-
- // evaluate_rook() assigns bonuses and penalties to a rook of a given
- // color on a given square.
-
- void evaluate_rook(const Position &p, Square s, Color us, EvalInfo &ei) {
-
- Color them = opposite_color(us);
-
- // 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)) {
- ei.mgValue += Sign[us] * RookOpenFileBonus;
- ei.egValue += Sign[us] * RookOpenFileBonus;
- }
- else {
- ei.mgValue += Sign[us] * RookHalfOpenFileBonus;
- ei.egValue += Sign[us] * RookHalfOpenFileBonus;
- }
- }
+ mob = (Piece != QUEEN ? popcount<Max15>(b & mobilityArea)
+ : popcount<Full >(b & mobilityArea));
- // Rook on 7th rank:
- if(pawn_rank(us, s) == RANK_7 &&
- pawn_rank(us, p.king_square(them)) == RANK_8) {
- ei.mgValue += Sign[us] * MidgameRookOn7thBonus;
- ei.egValue += Sign[us] * EndgameRookOn7thBonus;
- }
+ mobility += MobilityBonus[Piece][mob];
- //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;
-
- // King attack
- if(b & ei.attackZone[us]) {
- ei.attackCount[us]++;
- ei.attackWeight[us] += RookAttackWeight;
- Bitboard bb = (b & ei.attackedBy[them][KING]);
- if(bb) ei.attacked[us] += count_1s_max_15(bb);
- }
+ // 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();
+
+ assert(b);
- // Mobility
- int mob = count_1s_max_15(b & ~p.pieces_of_color(us));
- ei.mgMobility += Sign[us] * MidgameRookMobilityBonus[mob];
- ei.egMobility += Sign[us] * EndgameRookMobilityBonus[mob];
-
- // Penalize rooks which are trapped inside a king which has lost the
- // right to castle:
- if(mob <= 6 && !ei.pi->file_is_half_open(us, f)) {
- Square ksq = p.king_square(us);
- if(square_file(ksq) >= FILE_E && square_file(s) > square_file(ksq) &&
- (pawn_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);
+ if (!more_than_one(b) && (b & pos.pieces(Them)))
+ score += ThreatBonus[Piece][type_of(pos.piece_on(lsb(b)))];
}
- }
- else if(square_file(ksq) <= FILE_D && square_file(s) < square_file(ksq)
- && (pawn_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);
+
+ // 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];
+
+ // Bishop and knight outposts squares
+ if ( (Piece == BISHOP || Piece == KNIGHT)
+ && !(pos.pieces(Them, PAWN) & attack_span_mask(Us, s)))
+ score += evaluate_outposts<Piece, Us>(pos, ei, s);
+
+ 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<Max15>(pawns);
+ }
+
+ // Special extra evaluation for bishops
+ if (Piece == BISHOP && pos.is_chess960())
+ {
+ // 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;
+ }
+ }
+ }
+
+ // Special extra evaluation for rooks
+ if (Piece == ROOK)
+ {
+ // 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);
+ }
}
- }
}
+
+ 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.
-
- void evaluate_queen(const Position &p, Square s, Color us, EvalInfo &ei) {
+ // evaluate_threats<>() assigns bonuses according to the type of attacking piece
+ // and the type of attacked one.
- Color them = opposite_color(us);
+ template<Color Us>
+ Score evaluate_threats(const Position& pos, EvalInfo& ei) {
- // Queen on 7th rank:
- if(pawn_rank(us, s) == RANK_7 &&
- pawn_rank(us, p.king_square(them)) == RANK_8) {
- ei.mgValue += Sign[us] * MidgameQueenOn7thBonus;
- ei.egValue += Sign[us] * EndgameQueenOn7thBonus;
- }
+ const Color Them = (Us == WHITE ? BLACK : WHITE);
+
+ Bitboard b, undefendedMinors, weakEnemies;
+ Score score = SCORE_ZERO;
+
+ // Undefended minors get penalized even if not under attack
+ undefendedMinors = pos.pieces(Them)
+ & (pos.pieces(BISHOP) | pos.pieces(KNIGHT))
+ & ~ei.attackedBy[Them][0];
- Bitboard b = p.queen_attacks(s);
- ei.attackedBy[us][QUEEN] |= b;
+ if (undefendedMinors)
+ score += more_than_one(undefendedMinors) ? UndefendedMinorPenalty * 2
+ : UndefendedMinorPenalty;
- // King attack
- if(b & ei.attackZone[us]) {
- ei.attackCount[us]++;
- ei.attackWeight[us] += QueenAttackWeight;
- Bitboard bb = (b & ei.attackedBy[them][KING]);
- if(bb) ei.attacked[us] += count_1s_max_15(bb);
+ // 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++)
+ {
+ b = ei.attackedBy[Us][pt1] & weakEnemies;
+ if (b)
+ for (PieceType pt2 = PAWN; pt2 < KING; pt2++)
+ if (b & pos.pieces(pt2))
+ score += ThreatBonus[pt1][pt2];
}
-
- // Mobility
- int mob = count_1s(b & ~p.pieces_of_color(us));
- ei.mgMobility += Sign[us] * MidgameQueenMobilityBonus[mob];
- ei.egMobility += Sign[us] * EndgameQueenMobilityBonus[mob];
+ return score;
}
- // evaluate_king() assigns bonuses and penalties to a king of a given
- // color on a given square.
-
- void evaluate_king(const Position &p, Square s, Color us, EvalInfo &ei) {
-
- int shelter = 0, sign = Sign[us];
-
- // King shelter.
- if(pawn_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);
- }
+ // evaluate_pieces_of_color<>() assigns bonuses and penalties to all the
+ // pieces of a given color.
- // 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);
- }
- }
- }
- }
- }
- }
+ template<Color Us, bool Trace>
+ Score evaluate_pieces_of_color(const Position& pos, EvalInfo& ei, Score& mobility) {
+
+ const Color Them = (Us == WHITE ? BLACK : WHITE);
+
+ Score score = mobility = SCORE_ZERO;
- // 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));
- }
+ // 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<KNIGHT, Us, Trace>(pos, ei, mobility, mobilityArea);
+ score += evaluate_pieces<BISHOP, Us, Trace>(pos, ei, mobility, mobilityArea);
+ score += evaluate_pieces<ROOK, Us, Trace>(pos, ei, mobility, mobilityArea);
+ score += evaluate_pieces<QUEEN, Us, Trace>(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<Color Us, bool Trace>
+ 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<Us>(pos, ksq);
+
+ // King safety. This is quite complicated, and is almost certainly far
+ // from optimally tuned.
+ 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<Max15>(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<Max15>(b)
+ * (Them == pos.side_to_move() ? 2 : 1);
}
- }
-
- // Analyse safe distance checks:
- if(QueenCheckBonus > 0 || RookCheckBonus > 0) {
- b = p.rook_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);
-
- // 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 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);
- }
+ // 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);
+
+ // Consider only squares where the enemy rook gives check
+ b &= PseudoAttacks[ROOK][ksq];
+
+ 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<Max15>(b)
+ * (Them == pos.side_to_move() ? 2 : 1);
+ }
- // Has a mate threat been found? We don't do anything here if the
- // side with the mating move is the side to move, because in that
- // case the mating side will get a huge bonus at the end of the main
- // evaluation function instead.
- if(ei.mateThreat[them] != MOVE_NONE)
- attackUnits += MateThreatBonus;
-
- // Ensure that attackUnits is between 0 and 99, in order to avoid array
- // out of bounds errors:
- if(attackUnits < 0) attackUnits = 0;
- if(attackUnits >= 100) attackUnits = 99;
-
- // Finally, extract the king safety score from the SafetyTable[] array.
- // Add the score to the evaluation, and also to ei.futilityMargin. The
- // reason for adding the king safety score to the futility margin is
- // that the king safety scores can sometimes be very big, and that
- // capturing a single attacking piece can therefore result in a score
- // change far bigger than the value of the captured piece.
- Value v = apply_weight(SafetyTable[attackUnits], WeightKingSafety[us]);
- ei.mgValue -= sign * v;
- if(us == p.side_to_move())
- ei.futilityMargin += v;
+ // Analyse enemy's safe distance checks for sliders and knights
+ safe = ~(pos.pieces(Them) | ei.attackedBy[Us][0]);
+
+ b1 = pos.attacks_from<ROOK>(ksq) & safe;
+ b2 = pos.attacks_from<BISHOP>(ksq) & safe;
+
+ // Enemy queen safe checks
+ b = (b1 | b2) & ei.attackedBy[Them][QUEEN];
+ if (b)
+ attackUnits += QueenCheckBonus * popcount<Max15>(b);
+
+ // Enemy rooks safe checks
+ b = b1 & ei.attackedBy[Them][ROOK];
+ if (b)
+ attackUnits += RookCheckBonus * popcount<Max15>(b);
+
+ // Enemy bishops safe checks
+ b = b2 & ei.attackedBy[Them][BISHOP];
+ if (b)
+ attackUnits += BishopCheckBonus * popcount<Max15>(b);
+
+ // Enemy knights safe checks
+ b = pos.attacks_from<KNIGHT>(ksq) & ei.attackedBy[Them][KNIGHT] & safe;
+ if (b)
+ attackUnits += KnightCheckBonus * popcount<Max15>(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]);
}
+
+ if (Trace)
+ TracedScores[Us][KING] = score;
+
+ 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(pawn_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<Color Us>
+ Score evaluate_passed_pawns(const Position& pos, EvalInfo& ei) {
+
+ const Color Them = (Us == WHITE ? BLACK : WHITE);
+
+ Bitboard b, squaresToQueen, defendedSquares, unsafeSquares, supportingPawns;
+ Score score = SCORE_ZERO;
+
+ b = ei.pi->passed_pawns(Us);
- // 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 - pawn_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);
+ 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<ROOK>(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.
-
- 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;
+ // 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.
- assert(square_is_ok(s));
- assert(pos.piece_on(s) == bishop_of_color(us));
+ Score evaluate_unstoppable_pawns(const Position& pos, EvalInfo& ei) {
- 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);
- }
+ 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(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;
- }
+ // 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;
- }
+ 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.
-
- void evaluate_trapped_bishop_a1h1(const Position &pos, Square s, Color us,
- EvalInfo &ei) {
- Piece pawn = pawn_of_color(us);
- Square b2, b3, c3;
-
- assert(Chess960);
- assert(square_is_ok(s));
- assert(pos.piece_on(s) == bishop_of_color(us));
-
- if(square_file(s) == FILE_A) {
- b2 = relative_square(us, SQ_B2);
- b3 = relative_square(us, SQ_B3);
- c3 = relative_square(us, SQ_C3);
+ // 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)));
+
+ // Add moves needed to free the path from friendly pieces and retest condition
+ movesToGo += popcount<Max15>(queeningPath & pos.pieces(c));
+
+ if (movesToGo >= oppMovesToGo && !pathDefended)
+ continue;
+
+ 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;
+
+ // 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);
+
+ 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);
+ }
+ }
- if(!pos.square_is_empty(b3))
- penalty = 2*TrappedBishopA1H1Penalty;
- else if(pos.piece_on(c3) == pawn)
- penalty = TrappedBishopA1H1Penalty;
- else
- penalty = TrappedBishopA1H1Penalty / 2;
-
- ei.mgValue -= Sign[us] * penalty;
- ei.egValue -= Sign[us] * penalty;
+ // 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<Color Us>
+ 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]);
+
+ // 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);
- inline Value apply_weight(Value v, int w) {
- return (v*w) / 0x100;
+ return popcount<Max15>(safe) + popcount<Max15>(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.
-
- 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(ph >= PHASE_ENDGAME && ph <= PHASE_MIDGAME);
+ // interpolate() interpolates between a middle game and an endgame score,
+ // based on game phase. It also scales the return value by a ScaleFactor array.
- if(ev > Value(0))
- ev = apply_scale_factor(ev, sf[WHITE]);
- else
- ev = apply_scale_factor(ev, sf[BLACK]);
+ Value interpolate(const Score& v, Phase ph, ScaleFactor sf) {
- // Superlinear interpolator
- int sli_ph = int(ph);
- sli_ph -= (64 - sli_ph) / 4;
- sli_ph = Min(PHASE_MIDGAME, Max(PHASE_ENDGAME, sli_ph)); // ceiling
+ 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);
- Value result = Value(int((mv * sli_ph + ev * (128 - sli_ph)) / 128));
- return Value(int(result) & ~(GrainSize - 1));
+ 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));
}
- // 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.
-
- int count_1s_8bit(Bitboard b) {
- return int(BitCount8Bit[b & 0xFF]);
+ // 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) {
+
+ // Scale option value from 100 to 256
+ int mg = Options[mgOpt] * 256 / 100;
+ int eg = Options[egOpt] * 256 / 100;
+
+ 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); }
- int compute_weight(int uciWeight, int internalWeight) {
- uciWeight = (uciWeight * 0x100) / 100;
- return (uciWeight * internalWeight) / 0x100;
+ void trace_add(int idx, Score wScore, Score bScore) {
+
+ 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)));
- }
- 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);
+
+ // 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";
+ }
}
-
}
projects / stockfish / blobdiff