/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
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"
+namespace {
+
+ // Struct EvalInfo contains various information computed and collected
+ // by the evaluation functions.
+ struct EvalInfo {
+
+ // Pointers to material and pawn hash table entries
+ Material::Entry* mi;
+ Pawns::Entry* pi;
+
+ // attackedBy[color][piece type] is a bitboard representing all squares
+ // attacked by a given color and piece type, attackedBy[color][ALL_PIECES]
+ // contains all squares attacked by the given color.
+ Bitboard attackedBy[COLOR_NB][PIECE_TYPE_NB];
+
+ // kingRing[color] is the zone around the king which is considered
+ // by the king safety evaluation. This consists of the squares directly
+ // adjacent to the king, and the three (or two, for a king on an edge file)
+ // squares two ranks in front of the king. For instance, if black's king
+ // is on g8, kingRing[BLACK] is a bitboard containing the squares f8, h8,
+ // f7, g7, h7, f6, g6 and h6.
+ Bitboard kingRing[COLOR_NB];
+
+ // kingAttackersCount[color] is the number of pieces of the given color
+ // which attack a square in the kingRing of the enemy king.
+ int kingAttackersCount[COLOR_NB];
+
+ // kingAttackersWeight[color] is the sum of the "weight" of the pieces of the
+ // given color which attack a square in the kingRing of the enemy king. The
+ // weights of the individual piece types are given by the variables
+ // QueenAttackWeight, RookAttackWeight, BishopAttackWeight and
+ // KnightAttackWeight in evaluate.cpp
+ int kingAttackersWeight[COLOR_NB];
+
+ // kingAdjacentZoneAttacksCount[color] is the number of attacks to squares
+ // directly adjacent to the king of the given color. Pieces which attack
+ // more than one square are counted multiple times. For instance, if black's
+ // king is on g8 and there's a white knight on g5, this knight adds
+ // 2 to kingAdjacentZoneAttacksCount[BLACK].
+ int kingAdjacentZoneAttacksCount[COLOR_NB];
+
+ Bitboard pinnedPieces[COLOR_NB];
+ };
-////
-//// Local definitions
-////
+ namespace Tracing {
-namespace {
+ enum Terms { // First 8 entries are for PieceType
+ PST = 8, IMBALANCE, MOBILITY, THREAT, PASSED, SPACE, TOTAL, TERMS_NB
+ };
- const int Sign[2] = { 1, -1 };
+ Score terms[COLOR_NB][TERMS_NB];
+ EvalInfo ei;
+ ScaleFactor sf;
- // Evaluation grain size, must be a power of 2
- const int GrainSize = 8;
+ double to_cp(Value v);
+ void add_term(int idx, Score term_w, Score term_b = SCORE_ZERO);
+ void format_row(std::stringstream& ss, const char* name, int idx);
+ std::string do_trace(const Position& pos);
+ }
// Evaluation weights, initialized from UCI options
enum { Mobility, PawnStructure, PassedPawns, Space, KingDangerUs, KingDangerThem };
- Score Weights[6];
+ struct Weight { int mg, eg; } Weights[6];
typedef Value V;
#define S(mg, eg) make_score(mg, eg)
//
// Values modified by Joona Kiiski
const Score WeightsInternal[] = {
- S(248, 271), S(233, 201), S(252, 259), S(46, 0), S(247, 0), S(259, 0)
+ S(289, 344), S(233, 201), S(221, 273), S(46, 0), S(271, 0), S(307, 0)
};
- // Knight mobility bonus in middle game and endgame, indexed by the number
- // of attacked squares not occupied by friendly piecess.
- const Score KnightMobilityBonus[16] = {
- S(-38,-33), S(-25,-23), S(-12,-13), S( 0,-3),
- S( 12, 7), S( 25, 17), S( 31, 22), S(38, 27), S(38, 27)
+ // MobilityBonus[PieceType][attacked] contains bonuses for middle and end
+ // game, indexed by piece type and number of attacked squares not occupied by
+ // friendly pieces.
+ const Score MobilityBonus[][32] = {
+ {}, {},
+ { S(-35,-30), S(-22,-20), S(-9,-10), S( 3, 0), S(15, 10), S(27, 20), // Knights
+ S( 37, 28), S( 42, 31), S(44, 33) },
+ { S(-22,-27), S( -8,-13), S( 6, 1), S(20, 15), S(34, 29), S(48, 43), // Bishops
+ S( 60, 55), S( 68, 63), S(74, 68), S(77, 72), S(80, 75), S(82, 77),
+ S( 84, 79), S( 86, 81) },
+ { S(-17,-33), S(-11,-16), S(-5, 0), S( 1, 16), S( 7, 32), S(13, 48), // Rooks
+ S( 18, 64), S( 22, 80), S(26, 96), S(29,109), S(31,115), S(33,119),
+ S( 35,122), S( 36,123), S(37,124) },
+ { S(-12,-20), S( -8,-13), S(-5, -7), S(-2, -1), S( 1, 5), S( 4, 11), // Queens
+ S( 7, 17), S( 10, 23), S(13, 29), S(16, 34), S(18, 38), S(20, 40),
+ S( 22, 41), S( 23, 41), S(24, 41), S(25, 41), S(25, 41), S(25, 41),
+ S( 25, 41), S( 25, 41), S(25, 41), S(25, 41), S(25, 41), S(25, 41),
+ S( 25, 41), S( 25, 41), S(25, 41), S(25, 41) }
};
- // Bishop mobility bonus in middle game and endgame, indexed by the number
- // of attacked squares not occupied by friendly pieces. X-ray attacks through
- // queens are also included.
- const Score BishopMobilityBonus[16] = {
- S(-25,-30), S(-11,-16), S( 3, -2), S(17, 12),
- S( 31, 26), S( 45, 40), S(57, 52), S(65, 60),
- S( 71, 65), S( 74, 69), S(76, 71), S(78, 73),
- S( 79, 74), S( 80, 75), S(81, 76), S(81, 76)
+ // Outpost[PieceType][Square] contains bonuses for knights and bishops outposts,
+ // indexed by piece type and square (from white's point of view).
+ const Value Outpost[][SQUARE_NB] = {
+ {// A B C D E F G H
+ V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // Knights
+ V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0),
+ V(0), V(0), V(4), V(8), V(8), V(4), V(0), V(0),
+ V(0), V(4),V(17),V(26),V(26),V(17), V(4), V(0),
+ V(0), V(8),V(26),V(35),V(35),V(26), V(8), V(0),
+ V(0), V(4),V(17),V(17),V(17),V(17), V(4), V(0) },
+ {
+ V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // Bishops
+ V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0),
+ V(0), V(0), V(5), V(5), V(5), V(5), V(0), V(0),
+ V(0), V(5),V(10),V(10),V(10),V(10), V(5), V(0),
+ V(0),V(10),V(21),V(21),V(21),V(21),V(10), V(0),
+ V(0), V(5), V(8), V(8), V(8), V(8), V(5), V(0) }
};
- // Rook mobility bonus in middle game and endgame, indexed by the number
- // of attacked squares not occupied by friendly pieces. X-ray attacks through
- // queens and rooks are also included.
- const Score RookMobilityBonus[16] = {
- S(-20,-36), S(-14,-19), S(-8, -3), S(-2, 13),
- S( 4, 29), S( 10, 46), S(14, 62), S(19, 79),
- S( 23, 95), S( 26,106), S(27,111), S(28,114),
- S( 29,116), S( 30,117), S(31,118), S(32,118)
+ // Threat[attacking][attacked] contains bonuses according to which piece
+ // type attacks which one.
+ const Score Threat[][PIECE_TYPE_NB] = {
+ { S(0, 0), S( 7, 39), S(24, 49), S(24, 49), S(41,100), S(41,100) }, // Minor
+ { S(0, 0), S(15, 39), S(15, 45), S(15, 45), S(15, 45), S(24, 49) } // Major
};
- // Queen mobility bonus in middle game and endgame, indexed by the number
- // of attacked squares not occupied by friendly pieces.
- const Score QueenMobilityBonus[32] = {
- S(-10,-18), S(-8,-13), S(-6, -7), S(-3, -2), S(-1, 3), S( 1, 8),
- S( 3, 13), S( 5, 19), S( 8, 23), S(10, 27), S(12, 32), S(15, 34),
- S( 16, 35), S(17, 35), S(18, 35), S(20, 35), S(20, 35), S(20, 35),
- S( 20, 35), S(20, 35), S(20, 35), S(20, 35), S(20, 35), S(20, 35),
- S( 20, 35), S(20, 35), S(20, 35), S(20, 35), S(20, 35), S(20, 35),
- S( 20, 35), S(20, 35)
+ // ThreatenedByPawn[PieceType] contains a penalty according to which piece
+ // type is attacked by an enemy pawn.
+ const Score ThreatenedByPawn[] = {
+ S(0, 0), S(0, 0), S(56, 70), S(56, 70), S(76, 99), S(86, 118)
};
- // Pointers table to access mobility tables through piece type
- const Score* MobilityBonus[8] = { 0, 0, KnightMobilityBonus, BishopMobilityBonus,
- RookMobilityBonus, QueenMobilityBonus, 0, 0 };
-
- // Outpost bonuses for knights and bishops, indexed by square (from white's
- // point of view).
- const Value KnightOutpostBonus[64] = {
- // A B C D E F G H
- V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // 1
- V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // 2
- V(0), V(0), V(4), V(8), V(8), V(4), V(0), V(0), // 3
- V(0), V(4),V(17),V(26),V(26),V(17), V(4), V(0), // 4
- V(0), V(8),V(26),V(35),V(35),V(26), V(8), V(0), // 5
- V(0), V(4),V(17),V(17),V(17),V(17), V(4), V(0), // 6
- V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // 7
- V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0) // 8
- };
+ #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(21),V(21),V(21),V(21),V(10), V(0), // 5
- V(0), V(5), V(8), V(8), V(8), V(8), V(5), V(0), // 6
- V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // 7
- V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0) // 8
- };
+ const Score Tempo = make_score(24, 11);
+ const Score RookOn7th = make_score(11, 20);
+ const Score RookOnPawn = make_score(10, 28);
+ const Score RookOpenFile = make_score(43, 21);
+ const Score RookSemiopenFile = make_score(19, 10);
+ const Score BishopPawns = make_score( 8, 12);
+ const Score KnightPawns = make_score( 8, 4);
+ const Score MinorBehindPawn = make_score(16, 0);
+ const Score UndefendedMinor = make_score(25, 10);
+ const Score TrappedRook = make_score(90, 0);
+ const Score Unstoppable = make_score( 0, 20);
- // ThreatBonus[][] contains bonus according to which piece type
- // attacks which one.
- #define Z S(0, 0)
-
- const Score ThreatBonus[8][8] = {
- { Z, Z, Z, Z, Z, Z, Z, Z }, // not used
- { Z, S(18,37), Z, S(37,47), S(55,97), S(55,97), Z, Z }, // KNIGHT attacks
- { Z, S(18,37), S(37,47), Z, S(55,97), S(55,97), Z, Z }, // BISHOP attacks
- { Z, S( 9,27), S(27,47), S(27,47), Z, S(37,47), Z, Z }, // ROOK attacks
- { Z, S(27,37), S(27,37), S(27,37), S(27,37), Z, Z, Z }, // QUEEN attacks
- { Z, Z, Z, Z, Z, Z, Z, Z }, // not used
- { Z, Z, Z, Z, Z, Z, Z, Z }, // not used
- { Z, Z, Z, Z, Z, Z, Z, Z } // not used
- };
+ // Penalty for a bishop on a1/h1 (a8/h8 for black) which is trapped by
+ // a friendly pawn on b2/g2 (b7/g7 for black). This can obviously only
+ // happen in Chess960 games.
+ const Score TrappedBishopA1H1 = make_score(50, 50);
- // ThreatedByPawnPenalty[] contains a penalty according to which piece
- // type is attacked by an enemy pawn.
- const Score ThreatedByPawnPenalty[8] = {
- Z, Z, S(56, 70), S(56, 70), S(76, 99), S(86, 118), Z, Z
+ // SpaceMask[Color] contains the area of the board which is considered
+ // by the space evaluation. In the middlegame, each side is given a bonus
+ // based on how many squares inside this area are safe and available for
+ // friendly minor pieces.
+ const Bitboard SpaceMask[] = {
+ (FileCBB | FileDBB | FileEBB | FileFBB) & (Rank2BB | Rank3BB | Rank4BB),
+ (FileCBB | FileDBB | FileEBB | FileFBB) & (Rank7BB | Rank6BB | Rank5BB)
};
- #undef Z
- #undef S
+ // King danger constants and variables. The king danger scores are taken
+ // from KingDanger[]. Various little "meta-bonuses" measuring the strength
+ // of the enemy attack are added up into an integer, which is used as an
+ // index to KingDanger[].
+ //
+ // KingAttackWeights[PieceType] contains king attack weights by piece type
+ const int KingAttackWeights[] = { 0, 0, 2, 2, 3, 5 };
- // Bonus for unstoppable passed pawns
- const Value UnstoppablePawnValue = Value(0x500);
+ // Bonuses for enemy's safe checks
+ const int QueenContactCheck = 24;
+ const int RookContactCheck = 16;
+ const int QueenCheck = 12;
+ const int RookCheck = 8;
+ const int BishopCheck = 2;
+ const int KnightCheck = 3;
- // Rooks and queens on the 7th rank (modified by Joona Kiiski)
- const Score RookOn7thBonus = make_score(47, 98);
- const Score QueenOn7thBonus = make_score(27, 54);
+ // KingDanger[Color][attackUnits] contains the actual king danger weighted
+ // scores, indexed by color and by a calculated integer number.
+ Score KingDanger[COLOR_NB][128];
- // Rooks on open files (modified by Joona Kiiski)
- const Score RookOpenFileBonus = make_score(43, 43);
- const Score RookHalfOpenFileBonus = make_score(19, 19);
+ // Function prototypes
+ template<bool Trace>
+ Value do_evaluate(const Position& pos);
- // Penalty for rooks trapped inside a friendly king which has lost the
- // right to castle.
- const Value TrappedRookPenalty = Value(180);
+ template<Color Us>
+ void init_eval_info(const Position& pos, EvalInfo& ei);
- // Penalty for a bishop on a7/h7 (a2/h2 for black) which is trapped by
- // enemy pawns.
- const Score TrappedBishopA7H7Penalty = make_score(300, 300);
+ template<Color Us, bool Trace>
+ Score evaluate_pieces(const Position& pos, EvalInfo& ei, Score* mobility);
- // 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))
- };
+ template<Color Us, bool Trace>
+ Score evaluate_king(const Position& pos, const EvalInfo& ei);
- // Penalty for a bishop on a1/h1 (a8/h8 for black) which is trapped by
- // a friendly pawn on b2/g2 (b7/g7 for black). This can obviously only
- // happen in Chess960 games.
- const Score TrappedBishopA1H1Penalty = make_score(100, 100);
+ template<Color Us, bool Trace>
+ Score evaluate_threats(const Position& pos, const EvalInfo& ei);
- // 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))
- };
+ template<Color Us, bool Trace>
+ Score evaluate_passed_pawns(const Position& pos, const EvalInfo& ei);
- // The SpaceMask[color] contains the area of the board which is considered
- // by the space evaluation. In the middle game, each side is given a bonus
- // based on how many squares inside this area are safe and available for
- // friendly minor pieces.
- const Bitboard SpaceMask[2] = {
- (1ULL<<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)
- };
+ template<Color Us>
+ int evaluate_space(const Position& pos, const EvalInfo& ei);
- /// 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[].
-
- // Attack weights for each piece type and table indexed on piece type
- const int QueenAttackWeight = 5;
- const int RookAttackWeight = 3;
- const int BishopAttackWeight = 2;
- const int KnightAttackWeight = 2;
-
- const int AttackWeight[] = { 0, 0, KnightAttackWeight, BishopAttackWeight, RookAttackWeight, QueenAttackWeight };
-
- // Bonuses for safe checks
- const int QueenContactCheckBonus = 3;
- const int DiscoveredCheckBonus = 3;
- const int QueenCheckBonus = 2;
- const int RookCheckBonus = 1;
- const int BishopCheckBonus = 1;
- const int KnightCheckBonus = 1;
-
- // Scan for queen contact mates?
- const bool QueenContactMates = true;
-
- // Bonus for having a mate threat
- const 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,
- 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
- };
+ Score evaluate_unstoppable_pawns(const Position& pos, Color us, const EvalInfo& ei);
- // KingDangerTable[color][] contains the actual king danger weighted scores
- Score KingDangerTable[2][128];
+ Value interpolate(const Score& v, Phase ph, ScaleFactor sf);
+ Score apply_weight(Score v, const Weight& w);
+ Weight weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight);
+}
- // Pawn and material hash tables, indexed by the current thread id.
- // Note that they will be initialized at 0 being global variables.
- MaterialInfoTable* MaterialTable[MAX_THREADS];
- PawnInfoTable* PawnTable[MAX_THREADS];
- // Sizes of pawn and material hash tables
- const int PawnTableSize = 16384;
- const int MaterialTableSize = 1024;
+namespace Eval {
- // Function prototypes
- template<bool HasPopCnt>
- Value do_evaluate(const Position& pos, EvalInfo& ei, int threadID);
+ /// evaluate() is the main evaluation function. It always computes two
+ /// values, an endgame score and a middlegame score, and interpolates
+ /// between them based on the remaining material.
- template<Color Us, bool HasPopCnt>
- void evaluate_pieces_of_color(const Position& pos, EvalInfo& ei);
+ Value evaluate(const Position& pos) {
+ return do_evaluate<false>(pos);
+ }
- template<Color Us, bool HasPopCnt>
- void evaluate_king(const Position& pos, EvalInfo& ei);
- template<Color Us>
- void evaluate_threats(const Position& pos, EvalInfo& ei);
+ /// trace() is like evaluate(), but instead of returning a value, it returns
+ /// a string (suitable for outputting to stdout) that contains the detailed
+ /// descriptions and values of each evaluation term. It's mainly used for
+ /// debugging.
+ std::string trace(const Position& pos) {
+ return Tracing::do_trace(pos);
+ }
- template<Color Us, bool HasPopCnt>
- void evaluate_space(const Position& pos, EvalInfo& ei);
- template<Color Us>
- void evaluate_passed_pawns(const Position& pos, EvalInfo& ei);
-
- void evaluate_unstoppable_pawns(const Position& pos, EvalInfo& ei);
- void evaluate_trapped_bishop_a7h7(const Position& pos, Square s, Color us, EvalInfo& ei);
- void evaluate_trapped_bishop_a1h1(const Position& pos, Square s, Color us, EvalInfo& ei);
- inline Score apply_weight(Score v, Score weight);
- Value scale_by_game_phase(const Score& v, Phase ph, const ScaleFactor sf[]);
- Score weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight);
- void init_safety();
-}
+ /// init() computes evaluation weights from the corresponding UCI parameters
+ /// and setup king tables.
+ void init() {
-////
-//// Functions
-////
+ Weights[Mobility] = weight_option("Mobility (Midgame)", "Mobility (Endgame)", WeightsInternal[Mobility]);
+ Weights[PawnStructure] = weight_option("Pawn Structure (Midgame)", "Pawn Structure (Endgame)", WeightsInternal[PawnStructure]);
+ Weights[PassedPawns] = weight_option("Passed Pawns (Midgame)", "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]);
-/// evaluate() is the main evaluation function. It always computes two
-/// values, an endgame score and a middle game score, and interpolates
-/// between them based on the remaining material.
-Value evaluate(const Position& pos, EvalInfo& ei, int threadID) {
+ const int MaxSlope = 30;
+ const int Peak = 1280;
- return CpuHasPOPCNT ? do_evaluate<true>(pos, ei, threadID)
- : do_evaluate<false>(pos, ei, threadID);
-}
+ for (int t = 0, i = 1; i < 100; ++i)
+ {
+ t = std::min(Peak, std::min(int(0.4 * i * i), t + MaxSlope));
-namespace {
+ KingDanger[1][i] = apply_weight(make_score(t, 0), Weights[KingDangerUs]);
+ KingDanger[0][i] = apply_weight(make_score(t, 0), Weights[KingDangerThem]);
+ }
+ }
+
+} // namespace Eval
-template<bool HasPopCnt>
-Value do_evaluate(const Position& pos, EvalInfo& ei, int threadID) {
- Bitboard b;
- ScaleFactor factor[2];
+namespace {
+
+template<bool Trace>
+Value do_evaluate(const Position& pos) {
- assert(pos.is_ok());
- assert(threadID >= 0 && threadID < MAX_THREADS);
- assert(!pos.is_check());
+ assert(!pos.checkers());
- memset(&ei, 0, sizeof(EvalInfo));
+ EvalInfo ei;
+ Score score, mobility[2] = { SCORE_ZERO, SCORE_ZERO };
+ Thread* thisThread = pos.this_thread();
- // Initialize by reading the incrementally updated scores included in the
- // position object (material + piece square tables)
- ei.value = pos.value();
+ // Initialize score by reading the incrementally updated scores included
+ // in the position object (material + piece square tables) and adding a
+ // 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 = MaterialTable[threadID]->get_material_info(pos);
- ei.value += ei.mi->material_value();
+ ei.mi = Material::probe(pos, thisThread->materialTable, thisThread->endgames);
+ score += ei.mi->material_value();
// If we have a specialized evaluation function for the current material
- // configuration, call it and return
+ // configuration, call it and return.
if (ei.mi->specialized_eval_exists())
return ei.mi->evaluate(pos);
- // After get_material_info() call that modifies them
- factor[WHITE] = ei.mi->scale_factor(pos, WHITE);
- factor[BLACK] = ei.mi->scale_factor(pos, BLACK);
-
// Probe the pawn hash table
- ei.pi = PawnTable[threadID]->get_pawn_info(pos);
- ei.value += apply_weight(ei.pi->pawns_value(), Weights[PawnStructure]);
-
- // Initialize king attack bitboards and king attack zones for both sides
- ei.attackedBy[WHITE][KING] = pos.attacks_from<KING>(pos.king_square(WHITE));
- ei.attackedBy[BLACK][KING] = pos.attacks_from<KING>(pos.king_square(BLACK));
- ei.kingZone[WHITE] = ei.attackedBy[BLACK][KING] | (ei.attackedBy[BLACK][KING] >> 8);
- ei.kingZone[BLACK] = ei.attackedBy[WHITE][KING] | (ei.attackedBy[WHITE][KING] << 8);
-
- // Initialize pawn attack bitboards for both sides
- ei.attackedBy[WHITE][PAWN] = ei.pi->pawn_attacks(WHITE);
- b = ei.attackedBy[WHITE][PAWN] & ei.attackedBy[BLACK][KING];
- if (b)
- ei.kingAttackersCount[WHITE] = count_1s_max_15<HasPopCnt>(b)/2;
-
- ei.attackedBy[BLACK][PAWN] = ei.pi->pawn_attacks(BLACK);
- b = ei.attackedBy[BLACK][PAWN] & ei.attackedBy[WHITE][KING];
- if (b)
- ei.kingAttackersCount[BLACK] = count_1s_max_15<HasPopCnt>(b)/2;
-
- // Evaluate pieces
- evaluate_pieces_of_color<WHITE, HasPopCnt>(pos, ei);
- evaluate_pieces_of_color<BLACK, HasPopCnt>(pos, ei);
-
- // Kings. Kings are evaluated after all other pieces for both sides,
- // because we need complete attack information for all pieces when computing
- // the king safety evaluation.
- evaluate_king<WHITE, HasPopCnt>(pos, ei);
- evaluate_king<BLACK, HasPopCnt>(pos, ei);
-
- // Evaluate tactical threats, we need full attack info including king
- evaluate_threats<WHITE>(pos, ei);
- evaluate_threats<BLACK>(pos, ei);
-
- // Evaluate passed pawns, we need full attack info including king
- evaluate_passed_pawns<WHITE>(pos, ei);
- evaluate_passed_pawns<BLACK>(pos, ei);
-
- // If one side has only a king, check whether exsists any unstoppable passed pawn
- if (!pos.non_pawn_material(WHITE) || !pos.non_pawn_material(BLACK))
- evaluate_unstoppable_pawns(pos, ei);
+ ei.pi = Pawns::probe(pos, thisThread->pawnsTable);
+ score += apply_weight(ei.pi->pawns_value(), Weights[PawnStructure]);
- Phase phase = ei.mi->game_phase();
+ // Initialize attack and king safety bitboards
+ init_eval_info<WHITE>(pos, ei);
+ init_eval_info<BLACK>(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)
+ // Evaluate pieces and mobility
+ score += evaluate_pieces<WHITE, Trace>(pos, ei, mobility)
+ - evaluate_pieces<BLACK, Trace>(pos, ei, mobility);
- ei.value += make_score(ei.pi->queenside_storm_value(WHITE) - ei.pi->kingside_storm_value(BLACK), 0);
+ score += apply_weight(mobility[WHITE] - mobility[BLACK], Weights[Mobility]);
- else if ( square_file(pos.king_square(WHITE)) <= FILE_D
- && square_file(pos.king_square(BLACK)) >= FILE_E)
+ // 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)
+ - evaluate_king<BLACK, Trace>(pos, ei);
- ei.value += make_score(ei.pi->kingside_storm_value(WHITE) - ei.pi->queenside_storm_value(BLACK), 0);
+ // Evaluate tactical threats, we need full attack information including king
+ score += evaluate_threats<WHITE, Trace>(pos, ei)
+ - evaluate_threats<BLACK, Trace>(pos, ei);
- // Evaluate space for both sides
- if (ei.mi->space_weight() > 0)
- {
- evaluate_space<WHITE, HasPopCnt>(pos, ei);
- evaluate_space<BLACK, HasPopCnt>(pos, ei);
- }
+ // Evaluate passed pawns, we need full attack information including king
+ score += evaluate_passed_pawns<WHITE, Trace>(pos, ei)
+ - evaluate_passed_pawns<BLACK, Trace>(pos, ei);
+
+ // If one side has only a king, score for potential unstoppable pawns
+ if (!pos.non_pawn_material(WHITE) || !pos.non_pawn_material(BLACK))
+ score += evaluate_unstoppable_pawns(pos, WHITE, ei)
+ - evaluate_unstoppable_pawns(pos, BLACK, ei);
+
+ // Evaluate space for both sides, only in middlegame
+ if (ei.mi->space_weight())
+ {
+ int s = evaluate_space<WHITE>(pos, ei) - evaluate_space<BLACK>(pos, ei);
+ score += apply_weight(s * ei.mi->space_weight(), Weights[Space]);
}
- // Mobility
- ei.value += apply_weight(ei.mobility, Weights[Mobility]);
+ // Scale winning side if position is more drawish than 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 ( phase < PHASE_MIDGAME
- && pos.opposite_colored_bishops()
- && ( (factor[WHITE] == SCALE_FACTOR_NORMAL && eg_value(ei.value) > Value(0))
- || (factor[BLACK] == SCALE_FACTOR_NORMAL && eg_value(ei.value) < Value(0))))
+ // colored bishop endgames, and use a lower scale for those.
+ if ( ei.mi->game_phase() < PHASE_MIDGAME
+ && pos.opposite_bishops()
+ && (sf == SCALE_FACTOR_NORMAL || sf == SCALE_FACTOR_ONEPAWN))
{
- ScaleFactor sf;
-
- // Only the two bishops ?
- if ( pos.non_pawn_material(WHITE) == BishopValueMidgame
- && pos.non_pawn_material(BLACK) == BishopValueMidgame)
+ // Ignoring any pawns, do both sides only have a single bishop and no
+ // other pieces?
+ if ( pos.non_pawn_material(WHITE) == BishopValueMg
+ && pos.non_pawn_material(BLACK) == BishopValueMg)
{
// Check for KBP vs KB with only a single pawn that is almost
// certainly a draw or at least two pawns.
- bool one_pawn = (pos.piece_count(WHITE, PAWN) + pos.piece_count(BLACK, PAWN) == 1);
+ bool one_pawn = (pos.count<PAWN>(WHITE) + pos.count<PAWN>(BLACK) == 1);
sf = one_pawn ? ScaleFactor(8) : ScaleFactor(32);
}
else
// Endgame with opposite-colored bishops, but also other pieces. Still
// a bit drawish, but not as drawish as with only the two bishops.
- sf = ScaleFactor(50);
-
- if (factor[WHITE] == SCALE_FACTOR_NORMAL)
- factor[WHITE] = sf;
- if (factor[BLACK] == SCALE_FACTOR_NORMAL)
- factor[BLACK] = sf;
+ sf = ScaleFactor(50 * sf / SCALE_FACTOR_NORMAL);
}
- // Interpolate between the middle game and the endgame score
- Color stm = pos.side_to_move();
-
- Value v = Sign[stm] * scale_by_game_phase(ei.value, phase, factor);
-
- return (ei.mateThreat[stm] == MOVE_NONE ? v : 8 * QueenValueMidgame - v);
-}
-
-} // namespace
-
-/// init_eval() initializes various tables used by the evaluation function
-
-void init_eval(int threads) {
-
- assert(threads <= MAX_THREADS);
+ Value v = interpolate(score, ei.mi->game_phase(), sf);
- for (int i = 0; i < MAX_THREADS; i++)
+ // In case of tracing add all single evaluation contributions for both white and black
+ if (Trace)
{
- 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);
+ Tracing::add_term(Tracing::PST, pos.psq_score());
+ Tracing::add_term(Tracing::IMBALANCE, ei.mi->material_value());
+ Tracing::add_term(PAWN, ei.pi->pawns_value());
+ Score w = ei.mi->space_weight() * evaluate_space<WHITE>(pos, ei);
+ Score b = ei.mi->space_weight() * evaluate_space<BLACK>(pos, ei);
+ Tracing::add_term(Tracing::SPACE, apply_weight(w, Weights[Space]), apply_weight(b, Weights[Space]));
+ Tracing::add_term(Tracing::TOTAL, score);
+ Tracing::ei = ei;
+ Tracing::sf = sf;
}
-}
-
-/// quit_eval() releases heap-allocated memory at program termination
-
-void quit_eval() {
-
- for (int i = 0; i < MAX_THREADS; i++)
- {
- delete PawnTable[i];
- delete MaterialTable[i];
- PawnTable[i] = NULL;
- MaterialTable[i] = NULL;
- }
+ return pos.side_to_move() == WHITE ? v : -v;
}
-/// read_weights() reads evaluation weights from the corresponding UCI parameters
-
-void read_weights(Color us) {
+ // init_eval_info() initializes king bitboards for given color adding
+ // pawn attacks. To be done at the beginning of the evaluation.
- // King safety is asymmetrical. Our king danger level is weighted by
- // "Cowardice" UCI parameter, instead the opponent one by "Aggressiveness".
- const int kingDangerUs = (us == WHITE ? KingDangerUs : KingDangerThem);
- const int kingDangerThem = (us == WHITE ? KingDangerThem : KingDangerUs);
+ template<Color Us>
+ void init_eval_info(const Position& pos, EvalInfo& ei) {
- Weights[Mobility] = weight_option("Mobility (Middle Game)", "Mobility (Endgame)", WeightsInternal[Mobility]);
- Weights[PawnStructure] = weight_option("Pawn Structure (Middle Game)", "Pawn Structure (Endgame)", WeightsInternal[PawnStructure]);
- Weights[PassedPawns] = weight_option("Passed Pawns (Middle Game)", "Passed Pawns (Endgame)", WeightsInternal[PassedPawns]);
- Weights[Space] = weight_option("Space", "Space", WeightsInternal[Space]);
- Weights[kingDangerUs] = weight_option("Cowardice", "Cowardice", WeightsInternal[KingDangerUs]);
- Weights[kingDangerThem] = weight_option("Aggressiveness", "Aggressiveness", WeightsInternal[KingDangerThem]);
+ const Color Them = (Us == WHITE ? BLACK : WHITE);
+ const Square Down = (Us == WHITE ? DELTA_S : DELTA_N);
- // If running in analysis mode, make sure we use symmetrical king safety. We do this
- // by replacing both Weights[kingDangerUs] and Weights[kingDangerThem] by their average.
- if (get_option_value_bool("UCI_AnalyseMode"))
- Weights[kingDangerUs] = Weights[kingDangerThem] = (Weights[kingDangerUs] + Weights[kingDangerThem]) / 2;
+ ei.pinnedPieces[Us] = pos.pinned_pieces(Us);
- init_safety();
-}
+ 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.count<QUEEN>(Us) && pos.non_pawn_material(Us) > QueenValueMg + PawnValueMg)
+ {
+ ei.kingRing[Them] = b | shift_bb<Down>(b);
+ b &= ei.attackedBy[Us][PAWN];
+ ei.kingAttackersCount[Us] = b ? popcount<Max15>(b) : 0;
+ ei.kingAdjacentZoneAttacksCount[Us] = ei.kingAttackersWeight[Us] = 0;
+ }
+ else
+ ei.kingRing[Them] = ei.kingAttackersCount[Us] = 0;
+ }
-namespace {
- // evaluate_outposts() evaluates bishop and knight outposts squares
+ // evaluate_outposts() evaluates bishop and knight outpost squares
- template<PieceType Piece, Color Us>
- void evaluate_outposts(const Position& pos, EvalInfo& ei, Square s) {
+ template<PieceType Pt, Color Us>
+ Score evaluate_outposts(const Position& pos, EvalInfo& ei, Square s) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
+ assert (Pt == BISHOP || Pt == KNIGHT);
+
// Initial bonus based on square
- Value bonus = (Piece == BISHOP ? BishopOutpostBonus[relative_square(Us, s)]
- : KnightOutpostBonus[relative_square(Us, s)]);
+ Value bonus = Outpost[Pt == BISHOP][relative_square(Us, s)];
// Increase bonus if supported by pawn, especially if the opponent has
- // no minor piece which can exchange the outpost piece
- if (bonus && bit_is_set(ei.attackedBy[Us][PAWN], s))
+ // no minor piece which can trade with the outpost piece.
+ if (bonus && (ei.attackedBy[Us][PAWN] & s))
{
- if ( pos.pieces(KNIGHT, Them) == EmptyBoardBB
- && (SquaresByColorBB[square_color(s)] & pos.pieces(BISHOP, Them)) == EmptyBoardBB)
+ if ( !pos.pieces(Them, KNIGHT)
+ && !(squares_of_color(s) & pos.pieces(Them, BISHOP)))
bonus += bonus + bonus / 2;
else
bonus += bonus / 2;
}
- ei.value += Sign[Us] * make_score(bonus, bonus);
+
+ return make_score(bonus, bonus);
}
- // evaluate_pieces<>() assigns bonuses and penalties to the pieces of a given color
+ // evaluate_pieces() assigns bonuses and penalties to the pieces of a given color
- template<PieceType Piece, Color Us, bool HasPopCnt>
- void evaluate_pieces(const Position& pos, EvalInfo& ei, Bitboard no_mob_area) {
+ template<PieceType Pt, Color Us, bool Trace>
+ Score evaluate_pieces(const Position& pos, EvalInfo& ei, Score* mobility, Bitboard mobilityArea) {
Bitboard b;
- Square s, ksq;
- int mob;
- File f;
+ Square s;
+ Score score = SCORE_ZERO;
const Color Them = (Us == WHITE ? BLACK : WHITE);
- const Square* ptr = pos.piece_list_begin(Us, Piece);
+ const Square* pl = pos.list<Pt>(Us);
- while ((s = *ptr++) != SQ_NONE)
+ ei.attackedBy[Us][Pt] = 0;
+
+ while ((s = *pl++) != SQ_NONE)
{
// Find attacked squares, including x-ray attacks for bishops and rooks
- if (Piece == KNIGHT || Piece == QUEEN)
- b = pos.attacks_from<Piece>(s);
- else if (Piece == BISHOP)
- b = bishop_attacks_bb(s, pos.occupied_squares() & ~pos.pieces(QUEEN, Us));
- else if (Piece == ROOK)
- b = rook_attacks_bb(s, pos.occupied_squares() & ~pos.pieces(ROOK, QUEEN, Us));
- else
- assert(false);
+ b = Pt == BISHOP ? attacks_bb<BISHOP>(s, pos.pieces() ^ pos.pieces(Us, QUEEN))
+ : Pt == ROOK ? attacks_bb< ROOK>(s, pos.pieces() ^ pos.pieces(Us, ROOK, QUEEN))
+ : pos.attacks_from<Pt>(s);
+
+ if (ei.pinnedPieces[Us] & s)
+ b &= LineBB[pos.king_square(Us)][s];
- // Update attack info
- ei.attackedBy[Us][Piece] |= b;
+ ei.attackedBy[Us][Pt] |= b;
- // King attacks
- if (b & ei.kingZone[Us])
+ if (b & ei.kingRing[Them])
{
ei.kingAttackersCount[Us]++;
- ei.kingAttackersWeight[Us] += AttackWeight[Piece];
- Bitboard bb = (b & ei.attackedBy[Them][KING]);
+ ei.kingAttackersWeight[Us] += KingAttackWeights[Pt];
+ Bitboard bb = b & ei.attackedBy[Them][KING];
if (bb)
- ei.kingAdjacentZoneAttacksCount[Us] += count_1s_max_15<HasPopCnt>(bb);
+ ei.kingAdjacentZoneAttacksCount[Us] += popcount<Max15>(bb);
}
- // Mobility
- mob = (Piece != QUEEN ? count_1s_max_15<HasPopCnt>(b & no_mob_area)
- : count_1s<HasPopCnt>(b & no_mob_area));
+ int mob = Pt != QUEEN ? popcount<Max15>(b & mobilityArea)
+ : popcount<Full >(b & mobilityArea);
- ei.mobility += Sign[Us] * MobilityBonus[Piece][mob];
+ mobility[Us] += MobilityBonus[Pt][mob];
- // Decrease score if we are attacked by an enemy pawn. Remaining part
+ // Decrease score if we are attacked by an enemy pawn. The remaining part
// of threat evaluation must be done later when we have full attack info.
- if (bit_is_set(ei.attackedBy[Them][PAWN], s))
- ei.value -= Sign[Us] * ThreatedByPawnPenalty[Piece];
+ if (ei.attackedBy[Them][PAWN] & s)
+ score -= ThreatenedByPawn[Pt];
- // Bishop and knight outposts squares
- if ((Piece == BISHOP || Piece == KNIGHT) && pos.square_is_weak(s, Them))
- evaluate_outposts<Piece, Us>(pos, ei, s);
-
- // Special patterns: trapped bishops on a7/h7/a2/h2
- // and trapped bishops on a1/h1/a8/h8 in Chess960.
- if (Piece == BISHOP)
+ if (Pt == BISHOP || Pt == KNIGHT)
{
- if (bit_is_set(MaskA7H7[Us], s))
- evaluate_trapped_bishop_a7h7(pos, s, Us, ei);
-
- if (Chess960 && bit_is_set(MaskA1H1[Us], s))
- evaluate_trapped_bishop_a1h1(pos, s, Us, ei);
+ // Penalty for bishop with same colored pawns
+ if (Pt == BISHOP)
+ score -= BishopPawns * ei.pi->pawns_on_same_color_squares(Us, s);
+
+ // Penalty for knight when there are few enemy pawns
+ if (Pt == KNIGHT)
+ score -= KnightPawns * std::max(5 - pos.count<PAWN>(Them), 0);
+
+ // Bishop and knight outposts squares
+ if (!(pos.pieces(Them, PAWN) & pawn_attack_span(Us, s)))
+ score += evaluate_outposts<Pt, Us>(pos, ei, s);
+
+ // Bishop or knight behind a pawn
+ if ( relative_rank(Us, s) < RANK_5
+ && (pos.pieces(PAWN) & (s + pawn_push(Us))))
+ score += MinorBehindPawn;
}
- // Queen or rook on 7th rank
- if ( (Piece == ROOK || Piece == QUEEN)
- && relative_rank(Us, s) == RANK_7
- && relative_rank(Us, pos.king_square(Them)) == RANK_8)
+ if (Pt == ROOK)
{
- ei.value += Sign[Us] * (Piece == ROOK ? RookOn7thBonus : QueenOn7thBonus);
- }
+ // Rook on 7th rank and enemy king trapped on 8th
+ if ( relative_rank(Us, s) == RANK_7
+ && relative_rank(Us, pos.king_square(Them)) == RANK_8)
+ score += RookOn7th;
- // Special extra evaluation for rooks
- if (Piece == ROOK)
- {
- // Open and half-open files
- f = square_file(s);
- if (ei.pi->file_is_half_open(Us, f))
+ // Rook piece attacking enemy pawns on the same rank/file
+ if (relative_rank(Us, s) >= RANK_5)
{
- if (ei.pi->file_is_half_open(Them, f))
- ei.value += Sign[Us] * RookOpenFileBonus;
- else
- ei.value += Sign[Us] * RookHalfOpenFileBonus;
+ Bitboard pawns = pos.pieces(Them, PAWN) & PseudoAttacks[ROOK][s];
+ if (pawns)
+ score += popcount<Max15>(pawns) * RookOnPawn;
}
- // Penalize rooks which are trapped inside a king. Penalize more if
- // king has lost right to castle.
- if (mob > 6 || ei.pi->file_is_half_open(Us, f))
+ // Give a bonus for a rook on a open or semi-open file
+ if (ei.pi->semiopen(Us, file_of(s)))
+ score += ei.pi->semiopen(Them, file_of(s)) ? RookOpenFile : RookSemiopenFile;
+
+ if (mob > 3 || ei.pi->semiopen(Us, file_of(s)))
continue;
- ksq = pos.king_square(Us);
+ Square ksq = pos.king_square(Us);
- if ( square_file(ksq) >= FILE_E
- && square_file(s) > square_file(ksq)
- && (relative_rank(Us, ksq) == RANK_1 || square_rank(ksq) == square_rank(s)))
- {
- // Is there a half-open file between the king and the edge of the board?
- if (!ei.pi->has_open_file_to_right(Us, square_file(ksq)))
- ei.value -= Sign[Us] * make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2
- : (TrappedRookPenalty - mob * 16), 0);
- }
- else if ( square_file(ksq) <= FILE_D
- && square_file(s) < square_file(ksq)
- && (relative_rank(Us, ksq) == RANK_1 || square_rank(ksq) == square_rank(s)))
- {
- // Is there a half-open file between the king and the edge of the board?
- if (!ei.pi->has_open_file_to_left(Us, square_file(ksq)))
- ei.value -= Sign[Us] * make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2
- : (TrappedRookPenalty - mob * 16), 0);
- }
+ // Penalize rooks which are trapped by a king. Penalize more if the
+ // king has lost its castling capability.
+ if ( ((file_of(ksq) < FILE_E) == (file_of(s) < file_of(ksq)))
+ && (rank_of(ksq) == rank_of(s) || relative_rank(Us, ksq) == RANK_1)
+ && !ei.pi->semiopen_on_side(Us, file_of(ksq), file_of(ksq) < FILE_E))
+ score -= (TrappedRook - make_score(mob * 8, 0)) * (pos.can_castle(Us) ? 1 : 2);
}
- }
- }
-
-
- // evaluate_threats<>() assigns bonuses according to the type of attacking piece
- // and the type of attacked one.
- template<Color Us>
- void evaluate_threats(const Position& pos, EvalInfo& ei) {
-
- const Color Them = (Us == WHITE ? BLACK : WHITE);
+ // An important Chess960 pattern: A cornered bishop blocked by a friendly
+ // pawn diagonally in front of it is a very serious problem, especially
+ // when that pawn is also blocked.
+ if ( Pt == BISHOP
+ && pos.is_chess960()
+ && (s == relative_square(Us, SQ_A1) || s == relative_square(Us, SQ_H1)))
+ {
+ Square d = pawn_push(Us) + (file_of(s) == FILE_A ? DELTA_E : DELTA_W);
+ if (pos.piece_on(s + d) == make_piece(Us, PAWN))
+ score -= !pos.empty(s + d + pawn_push(Us)) ? TrappedBishopA1H1 * 4
+ : pos.piece_on(s + d + d) == make_piece(Us, PAWN) ? TrappedBishopA1H1 * 2
+ : TrappedBishopA1H1;
+ }
+ }
- Bitboard b;
- Score bonus = make_score(0, 0);
+ if (Trace)
+ Tracing::terms[Us][Pt] = score;
- // Enemy pieces not defended by a pawn and under our attack
- Bitboard weakEnemies = pos.pieces_of_color(Them)
- & ~ei.attackedBy[Them][PAWN]
- & ei.attackedBy[Us][0];
- if (!weakEnemies)
- return;
-
- // Add bonus according to type of attacked enemy pieces and to the
- // type of attacking piece, from knights to queens. Kings are not
- // considered because are already special handled in king evaluation.
- for (PieceType pt1 = KNIGHT; pt1 < KING; pt1++)
- {
- b = ei.attackedBy[Us][pt1] & weakEnemies;
- if (b)
- for (PieceType pt2 = PAWN; pt2 < KING; pt2++)
- if (b & pos.pieces(pt2))
- bonus += ThreatBonus[pt1][pt2];
- }
- ei.value += Sign[Us] * bonus;
+ return score;
}
- // evaluate_pieces_of_color<>() assigns bonuses and penalties to all the
+ // evaluate_pieces() assigns bonuses and penalties to all the
// pieces of a given color.
- template<Color Us, bool HasPopCnt>
- void evaluate_pieces_of_color(const Position& pos, EvalInfo& ei) {
+ template<Color Us, bool Trace>
+ Score evaluate_pieces(const Position& pos, EvalInfo& ei, Score* mobility) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
// Do not include in mobility squares protected by enemy pawns or occupied by our pieces
- const Bitboard no_mob_area = ~(ei.attackedBy[Them][PAWN] | pos.pieces_of_color(Us));
+ const Bitboard mobilityArea = ~(ei.attackedBy[Them][PAWN] | pos.pieces(Us, PAWN, KING));
- evaluate_pieces<KNIGHT, Us, HasPopCnt>(pos, ei, no_mob_area);
- evaluate_pieces<BISHOP, Us, HasPopCnt>(pos, ei, no_mob_area);
- evaluate_pieces<ROOK, Us, HasPopCnt>(pos, ei, no_mob_area);
- evaluate_pieces<QUEEN, Us, HasPopCnt>(pos, ei, no_mob_area);
+ Score score = evaluate_pieces<KNIGHT, Us, Trace>(pos, ei, mobility, mobilityArea)
+ + evaluate_pieces<BISHOP, Us, Trace>(pos, ei, mobility, mobilityArea)
+ + evaluate_pieces<ROOK, Us, Trace>(pos, ei, mobility, mobilityArea)
+ + 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];
+ // Sum up all attacked squares (updated in evaluate_pieces)
+ ei.attackedBy[Us][ALL_PIECES] = ei.attackedBy[Us][PAWN] | ei.attackedBy[Us][KNIGHT]
+ | ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK]
+ | ei.attackedBy[Us][QUEEN] | ei.attackedBy[Us][KING];
+ if (Trace)
+ Tracing::terms[Us][Tracing::MOBILITY] = apply_weight(mobility[Us], Weights[Mobility]);
+
+ return score;
}
- // evaluate_king<>() assigns bonuses and penalties to a king of a given color
+ // evaluate_king() assigns bonuses and penalties to a king of a given color
- template<Color Us, bool HasPopCnt>
- void evaluate_king(const Position& pos, EvalInfo& ei) {
+ template<Color Us, bool Trace>
+ Score evaluate_king(const Position& pos, const EvalInfo& ei) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
- Bitboard undefended, attackedByOthers, escapeSquares, occ, b, b2, safe;
- Square from, to;
- bool sente;
- int attackUnits, count, shelter = 0;
- const Square s = pos.king_square(Us);
+ Bitboard undefended, b, b1, b2, safe;
+ int attackUnits;
+ const Square ksq = pos.king_square(Us);
- // King shelter
- if (relative_rank(Us, s) <= RANK_4)
- {
- shelter = ei.pi->get_king_shelter(pos, Us, s);
- ei.value += Sign[Us] * make_score(shelter, 0);
- }
+ // 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 ( pos.piece_count(Them, QUEEN) >= 1
- && ei.kingAttackersCount[Them] >= 2
- && pos.non_pawn_material(Them) >= QueenValueMidgame + RookValueMidgame
- && ei.kingAdjacentZoneAttacksCount[Them])
+ // Main king safety evaluation
+ if (ei.kingAttackersCount[Them])
{
- // Is it the attackers turn to move?
- sente = (Them == pos.side_to_move());
-
- // Find the attacked squares around the king which has no defenders
- // apart from the king itself
- undefended = ei.attacked_by(Them) & ei.attacked_by(Us, KING);
- undefended &= ~( ei.attacked_by(Us, PAWN) | ei.attacked_by(Us, KNIGHT)
- | ei.attacked_by(Us, BISHOP) | ei.attacked_by(Us, ROOK)
- | ei.attacked_by(Us, QUEEN));
-
- // Initialize the 'attackUnits' variable, which is used later on as an
- // index to the KingDangerTable[] array. The initial value is based on
- // the number and types of the enemy's attacking pieces, the number of
- // attacked and undefended squares around our king, the square of the
- // king, and the quality of the pawn shelter.
- attackUnits = Min(25, (ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) / 2)
- + 3 * (ei.kingAdjacentZoneAttacksCount[Them] + count_1s_max_15<HasPopCnt>(undefended))
- + InitKingDanger[relative_square(Us, s)]
- - (shelter >> 5);
-
- // Analyse safe queen contact checks
- b = undefended & ei.attacked_by(Them, QUEEN) & ~pos.pieces_of_color(Them);
- if (b)
- {
- attackedByOthers = ei.attacked_by(Them, PAWN) | ei.attacked_by(Them, KNIGHT)
- | ei.attacked_by(Them, BISHOP) | ei.attacked_by(Them, ROOK);
+ // Find the attacked squares around the king which have no defenders
+ // apart from the king itself
+ undefended = ei.attackedBy[Them][ALL_PIECES]
+ & ei.attackedBy[Us][KING]
+ & ~( ei.attackedBy[Us][PAWN] | ei.attackedBy[Us][KNIGHT]
+ | ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK]
+ | ei.attackedBy[Us][QUEEN]);
+
+ // Initialize the 'attackUnits' variable, which is used later on as an
+ // index to the KingDanger[] array. The initial value is based on the
+ // number and types of the enemy's attacking pieces, the number of
+ // attacked and undefended squares around our king and the quality of
+ // the pawn shelter (current 'score' value).
+ attackUnits = std::min(20, (ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) / 2)
+ + 3 * (ei.kingAdjacentZoneAttacksCount[Them] + popcount<Max15>(undefended))
+ + 2 * (ei.pinnedPieces[Us] != 0)
+ - mg_value(score) / 32;
+
+ // Analyse the enemy's safe queen contact checks. Firstly, find the
+ // undefended squares around the king that are attacked by the enemy's
+ // queen...
+ b = undefended & ei.attackedBy[Them][QUEEN] & ~pos.pieces(Them);
+ if (b)
+ {
+ // ...and then remove squares not supported by another enemy piece
+ b &= ( ei.attackedBy[Them][PAWN] | ei.attackedBy[Them][KNIGHT]
+ | ei.attackedBy[Them][BISHOP] | ei.attackedBy[Them][ROOK]);
+
+ if (b)
+ attackUnits += QueenContactCheck
+ * popcount<Max15>(b)
+ * (Them == pos.side_to_move() ? 2 : 1);
+ }
- b &= attackedByOthers;
+ // Analyse the enemy's safe rook contact checks. Firstly, find the
+ // undefended squares around the king that are attacked by the enemy's
+ // rooks...
+ b = undefended & ei.attackedBy[Them][ROOK] & ~pos.pieces(Them);
+
+ // Consider only squares where the enemy's rook gives check
+ b &= PseudoAttacks[ROOK][ksq];
- // Squares attacked by the queen and supported by another enemy piece and
- // not defended by other pieces but our king.
if (b)
{
- // The bitboard b now contains the squares available for safe queen
- // contact checks.
- count = count_1s_max_15<HasPopCnt>(b);
- attackUnits += QueenContactCheckBonus * count * (sente ? 2 : 1);
-
- // Is there a mate threat?
- if (QueenContactMates && !pos.is_check())
- {
- escapeSquares = pos.attacks_from<KING>(s) & ~pos.pieces_of_color(Us) & ~attackedByOthers;
- occ = pos.occupied_squares();
- while (b)
- {
- to = pop_1st_bit(&b);
-
- // Do we have escape squares from queen contact check attack ?
- if (!(escapeSquares & ~queen_attacks_bb(to, occ & ClearMaskBB[s])))
- {
- // We have a mate, unless the queen is pinned or there
- // is an X-ray attack through the queen.
- for (int i = 0; i < pos.piece_count(Them, QUEEN); i++)
- {
- from = pos.piece_list(Them, QUEEN, i);
- if ( bit_is_set(pos.attacks_from<QUEEN>(from), to)
- && !bit_is_set(pos.pinned_pieces(Them), from)
- && !(rook_attacks_bb(to, occ & ClearMaskBB[from]) & pos.pieces(ROOK, QUEEN, Us))
- && !(bishop_attacks_bb(to, occ & ClearMaskBB[from]) & pos.pieces(BISHOP, QUEEN, Us)))
-
- // Set the mate threat move
- ei.mateThreat[Them] = make_move(from, to);
- }
- }
- }
- }
+ // ...and then remove squares not supported by another enemy piece
+ b &= ( ei.attackedBy[Them][PAWN] | ei.attackedBy[Them][KNIGHT]
+ | ei.attackedBy[Them][BISHOP] | ei.attackedBy[Them][QUEEN]);
+
+ if (b)
+ attackUnits += RookContactCheck
+ * popcount<Max15>(b)
+ * (Them == pos.side_to_move() ? 2 : 1);
}
- }
- // Analyse safe distance checks
- safe = ~(pos.pieces_of_color(Them) | ei.attacked_by(Us));
+ // Analyse the enemy's safe distance checks for sliders and knights
+ safe = ~(pos.pieces(Them) | ei.attackedBy[Us][ALL_PIECES]);
- if (QueenCheckBonus > 0 || RookCheckBonus > 0)
- {
- b = pos.attacks_from<ROOK>(s) & safe;
+ b1 = pos.attacks_from<ROOK>(ksq) & safe;
+ b2 = pos.attacks_from<BISHOP>(ksq) & safe;
- // Queen checks
- b2 = b & ei.attacked_by(Them, QUEEN);
- if (b2)
- attackUnits += QueenCheckBonus * count_1s_max_15<HasPopCnt>(b2);
+ // Enemy queen safe checks
+ b = (b1 | b2) & ei.attackedBy[Them][QUEEN];
+ if (b)
+ attackUnits += QueenCheck * popcount<Max15>(b);
- // Rook checks
- b2 = b & ei.attacked_by(Them, ROOK);
- if (b2)
- attackUnits += RookCheckBonus * count_1s_max_15<HasPopCnt>(b2);
- }
- if (QueenCheckBonus > 0 || BishopCheckBonus > 0)
- {
- b = pos.attacks_from<BISHOP>(s) & safe;
+ // Enemy rooks safe checks
+ b = b1 & ei.attackedBy[Them][ROOK];
+ if (b)
+ attackUnits += RookCheck * popcount<Max15>(b);
- // Queen checks
- b2 = b & ei.attacked_by(Them, QUEEN);
- if (b2)
- attackUnits += QueenCheckBonus * count_1s_max_15<HasPopCnt>(b2);
+ // Enemy bishops safe checks
+ b = b2 & ei.attackedBy[Them][BISHOP];
+ if (b)
+ attackUnits += BishopCheck * popcount<Max15>(b);
- // Bishop checks
- b2 = b & ei.attacked_by(Them, BISHOP);
- if (b2)
- attackUnits += BishopCheckBonus * count_1s_max_15<HasPopCnt>(b2);
- }
- if (KnightCheckBonus > 0)
- {
- b = pos.attacks_from<KNIGHT>(s) & safe;
+ // Enemy knights safe checks
+ b = pos.attacks_from<KNIGHT>(ksq) & ei.attackedBy[Them][KNIGHT] & safe;
+ if (b)
+ attackUnits += KnightCheck * popcount<Max15>(b);
- // Knight checks
- b2 = b & ei.attacked_by(Them, KNIGHT);
- if (b2)
- attackUnits += KnightCheckBonus * count_1s_max_15<HasPopCnt>(b2);
- }
+ // To index KingDanger[] attackUnits must be in [0, 99] range
+ attackUnits = std::min(99, std::max(0, attackUnits));
- // Analyse discovered checks (only for non-pawns right now, consider
- // adding pawns later).
- if (DiscoveredCheckBonus)
- {
- b = pos.discovered_check_candidates(Them) & ~pos.pieces(PAWN);
- if (b)
- attackUnits += DiscoveredCheckBonus * count_1s_max_15<HasPopCnt>(b) * (sente ? 2 : 1);
- }
+ // Finally, extract the king danger score from the KingDanger[]
+ // array and subtract the score from evaluation.
+ score -= KingDanger[Us == Search::RootColor][attackUnits];
+ }
+
+ if (Trace)
+ Tracing::terms[Us][KING] = score;
+
+ return score;
+ }
+
+
+ // evaluate_threats() assigns bonuses according to the type of attacking piece
+ // and the type of attacked one.
+
+ template<Color Us, bool Trace>
+ Score evaluate_threats(const Position& pos, const EvalInfo& ei) {
- // 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.
- attackUnits = Min(99, Max(0, attackUnits));
-
- // Finally, extract the king danger score from the KingDangerTable[] array.
- // Subtract the score from evaluation, and set ei.futilityMargin[].
- // The reason for storing the king danger score to futility margin
- // is that the king danger 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.
- ei.value -= Sign[Us] * KingDangerTable[Us][attackUnits];
- ei.futilityMargin[Us] = mg_value(KingDangerTable[Us][attackUnits]);
+ const Color Them = (Us == WHITE ? BLACK : WHITE);
+
+ Bitboard b, undefendedMinors, weakEnemies;
+ Score score = SCORE_ZERO;
+
+ // Undefended minors get penalized even if they are not under attack
+ undefendedMinors = pos.pieces(Them, BISHOP, KNIGHT)
+ & ~ei.attackedBy[Them][ALL_PIECES];
+
+ if (undefendedMinors)
+ score += UndefendedMinor;
+
+ // Enemy pieces not defended by a pawn and under our attack
+ weakEnemies = pos.pieces(Them)
+ & ~ei.attackedBy[Them][PAWN]
+ & ei.attackedBy[Us][ALL_PIECES];
+
+ // Add a bonus according if the attacking pieces are minor or major
+ if (weakEnemies)
+ {
+ b = weakEnemies & (ei.attackedBy[Us][KNIGHT] | ei.attackedBy[Us][BISHOP]);
+ if (b)
+ score += Threat[0][type_of(pos.piece_on(lsb(b)))];
+
+ b = weakEnemies & (ei.attackedBy[Us][ROOK] | ei.attackedBy[Us][QUEEN]);
+ if (b)
+ score += Threat[1][type_of(pos.piece_on(lsb(b)))];
}
+
+ if (Trace)
+ Tracing::terms[Us][Tracing::THREAT] = score;
+
+ return score;
}
- // evaluate_passed_pawns<>() evaluates the passed pawns of the given color
+ // evaluate_passed_pawns() evaluates the passed pawns of the given color
- template<Color Us>
- void evaluate_passed_pawns(const Position& pos, EvalInfo& ei) {
+ template<Color Us, bool Trace>
+ Score evaluate_passed_pawns(const Position& pos, const EvalInfo& ei) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
- Bitboard b = ei.pi->passed_pawns() & pos.pieces_of_color(Us);
+ Bitboard b, squaresToQueen, defendedSquares, unsafeSquares, supportingPawns;
+ Score score = SCORE_ZERO;
+
+ b = ei.pi->passed_pawns(Us);
while (b)
{
- Square s = pop_1st_bit(&b);
+ Square s = pop_lsb(&b);
- assert(pos.piece_on(s) == piece_of_color_and_type(Us, PAWN));
- assert(pos.pawn_is_passed(Us, s));
+ assert(pos.pawn_passed(Us, s));
int r = int(relative_rank(Us, s) - RANK_2);
- int tr = Max(0, r * (r - 1));
+ int rr = r * (r - 1);
// Base bonus based on rank
- Value mbonus = Value(20 * tr);
- Value ebonus = Value(10 + r * r * 10);
+ Value mbonus = Value(17 * rr);
+ Value ebonus = Value(7 * (rr + r + 1));
- // Adjust bonus based on king proximity
- if (tr)
+ if (rr)
{
Square blockSq = s + pawn_push(Us);
- ebonus -= Value(square_distance(pos.king_square(Us), blockSq) * 3 * tr);
- ebonus -= Value(square_distance(pos.king_square(Us), blockSq + pawn_push(Us)) * 1 * tr);
- ebonus += Value(square_distance(pos.king_square(Them), blockSq) * 6 * tr);
+ // Adjust bonus based on the king's proximity
+ ebonus += Value(square_distance(pos.king_square(Them), blockSq) * 5 * rr)
+ - Value(square_distance(pos.king_square(Us ), blockSq) * 2 * rr);
- // If the pawn is free to advance, increase bonus
- if (pos.square_is_empty(blockSq))
+ // If blockSq is not the queening square then consider also a second push
+ if (relative_rank(Us, blockSq) != RANK_8)
+ ebonus -= Value(rr * square_distance(pos.king_square(Us), blockSq + pawn_push(Us)));
+
+ // If the pawn is free to advance, then increase the bonus
+ if (pos.empty(blockSq))
{
- // There are no enemy pawns in the pawn's path
- Bitboard b2 = squares_in_front_of(Us, s);
+ squaresToQueen = forward_bb(Us, s);
- assert((b2 & pos.pieces(PAWN, Them)) == EmptyBoardBB);
+ // 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 ( unlikely(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][ALL_PIECES] | pos.pieces(Them));
- // Squares attacked by us
- Bitboard b4 = b2 & ei.attacked_by(Us);
+ if ( unlikely(forward_bb(Them, s) & pos.pieces(Us, ROOK, QUEEN))
+ && (forward_bb(Them, s) & pos.pieces(Us, ROOK, QUEEN) & pos.attacks_from<ROOK>(s)))
+ defendedSquares = squaresToQueen;
+ else
+ defendedSquares = squaresToQueen & ei.attackedBy[Us][ALL_PIECES];
- // Squares attacked or occupied by enemy pieces
- Bitboard b3 = b2 & (ei.attacked_by(Them) | pos.pieces_of_color(Them));
+ // If there aren't any enemy attacks, then assign a huge bonus.
+ // The bonus will be a bit smaller if at least the block square
+ // isn't attacked, otherwise assign the smallest possible bonus.
+ int k = !unsafeSquares ? 15 : !(unsafeSquares & blockSq) ? 9 : 3;
- // If there is an enemy rook or queen attacking the pawn from behind,
- // add all X-ray attacks by the rook or queen.
- if ( (squares_behind(Us, s) & pos.pieces(ROOK, QUEEN, Them))
- && (squares_behind(Us, s) & pos.pieces(ROOK, QUEEN, Them) & pos.attacks_from<QUEEN>(s)))
- b3 = b2;
-
- // Are any of the squares in the pawn's path attacked or occupied by the enemy?
- if (b3 == EmptyBoardBB)
- // No enemy attacks or pieces, huge bonus!
- // Even bigger if we protect the pawn's path
- ebonus += Value(tr * (b2 == b4 ? 17 : 15));
- else
- // OK, there are enemy attacks or pieces (but not pawns). Are those
- // squares which are attacked by the enemy also attacked by us ?
- // If yes, big bonus (but smaller than when there are no enemy attacks),
- // if no, somewhat smaller bonus.
- ebonus += Value(tr * ((b3 & b4) == b3 ? 13 : 8));
-
- // At last, add a small bonus when there are no *friendly* pieces
- // in the pawn's path.
- if ((b2 & pos.pieces_of_color(Us)) == EmptyBoardBB)
- ebonus += Value(tr);
+ // Assign a big bonus if the path to the queen is fully defended,
+ // otherwise assign a bit less of a bonus if at least the block
+ // square is defended.
+ if (defendedSquares == squaresToQueen)
+ k += 6;
+
+ else if (defendedSquares & blockSq)
+ k += (unsafeSquares & defendedSquares) == unsafeSquares ? 4 : 2;
+
+ mbonus += Value(k * rr), ebonus += Value(k * rr);
}
- } // tr != 0
+ } // rr != 0
- // If the pawn is supported by a friendly pawn, increase bonus
- Bitboard b1 = pos.pieces(PAWN, Us) & neighboring_files_bb(s);
- if (b1 & rank_bb(s))
+ // 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 (pos.attacks_from<PAWN>(s, Them) & b1)
+
+ else if (supportingPawns & rank_bb(s - pawn_push(Us)))
ebonus += Value(r * 12);
// Rook pawns are a special case: They are sometimes worse, and
// 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 (file_of(s) == FILE_A || file_of(s) == FILE_H)
{
- if ( pos.non_pawn_material(Them) <= KnightValueMidgame
- && pos.piece_count(Them, KNIGHT) <= 1)
+ if (pos.non_pawn_material(Them) <= KnightValueMg)
ebonus += ebonus / 4;
- else if (pos.pieces(ROOK, QUEEN, Them))
- ebonus -= ebonus / 4;
- }
-
- // Add the scores for this pawn to the middle game and endgame eval
- ei.value += Sign[Us] * apply_weight(make_score(mbonus, ebonus), Weights[PassedPawns]);
-
- } // while
- }
-
- // evaluate_unstoppable_pawns() evaluates the unstoppable passed pawns for both sides
-
- void evaluate_unstoppable_pawns(const Position& pos, EvalInfo& ei) {
-
- int movesToGo[2] = {0, 0};
- Square pawnToGo[2] = {SQ_NONE, SQ_NONE};
-
- for (Color c = WHITE; c <= BLACK; c++)
- {
- // Skip evaluation if other side has non-pawn pieces
- if (pos.non_pawn_material(opposite_color(c)))
- continue;
-
- Bitboard b = ei.pi->passed_pawns() & pos.pieces_of_color(c);
-
- while (b)
- {
- Square s = pop_1st_bit(&b);
- Square queeningSquare = relative_square(c, make_square(square_file(s), RANK_8));
- int d = square_distance(s, queeningSquare)
- - square_distance(pos.king_square(opposite_color(c)), queeningSquare)
- + int(c != pos.side_to_move());
-
- if (d < 0)
- {
- int mtg = RANK_8 - relative_rank(c, s);
- int blockerCount = count_1s_max_15(squares_in_front_of(c, s) & pos.occupied_squares());
- mtg += blockerCount;
- d += blockerCount;
- if (d < 0 && (!movesToGo[c] || movesToGo[c] > mtg))
- {
- movesToGo[c] = mtg;
- pawnToGo[c] = s;
- }
- }
+ else if (pos.pieces(Them, ROOK, QUEEN))
+ ebonus -= ebonus / 4;
}
- }
- // Neither side has an unstoppable passed pawn?
- if (!(movesToGo[WHITE] | movesToGo[BLACK]))
- return;
+ if (pos.count<PAWN>(Us) < pos.count<PAWN>(Them))
+ ebonus += ebonus / 4;
- // Does only one side have an unstoppable passed pawn?
- if (!movesToGo[WHITE] || !movesToGo[BLACK])
- {
- Color winnerSide = movesToGo[WHITE] ? WHITE : BLACK;
- ei.value += make_score(0, Sign[winnerSide] * (UnstoppablePawnValue - Value(0x40 * movesToGo[winnerSide])));
+ score += make_score(mbonus, ebonus);
}
- else
- { // Both sides have unstoppable pawns! Try to find out who queens
- // first. We begin by transforming 'movesToGo' to the number of
- // plies until the pawn queens for both sides.
- movesToGo[WHITE] *= 2;
- movesToGo[BLACK] *= 2;
- movesToGo[pos.side_to_move()]--;
-
- Color winnerSide = movesToGo[WHITE] < movesToGo[BLACK] ? WHITE : BLACK;
- Color loserSide = opposite_color(winnerSide);
-
- // If one side queens at least three plies before the other, that side wins
- if (movesToGo[winnerSide] <= movesToGo[loserSide] - 3)
- ei.value += Sign[winnerSide] * make_score(0, UnstoppablePawnValue - Value(0x40 * (movesToGo[winnerSide]/2)));
-
- // If one side queens one ply before the other and checks the king or attacks
- // the undefended opponent's queening square, that side wins. To avoid cases
- // where the opponent's king could move somewhere before first pawn queens we
- // consider only free paths to queen for both pawns.
- else if ( !(squares_in_front_of(WHITE, pawnToGo[WHITE]) & pos.occupied_squares())
- && !(squares_in_front_of(BLACK, pawnToGo[BLACK]) & pos.occupied_squares()))
- {
- assert(movesToGo[loserSide] - movesToGo[winnerSide] == 1);
-
- Square winnerQSq = relative_square(winnerSide, make_square(square_file(pawnToGo[winnerSide]), RANK_8));
- Square loserQSq = relative_square(loserSide, make_square(square_file(pawnToGo[loserSide]), RANK_8));
- Bitboard b = pos.occupied_squares();
- clear_bit(&b, pawnToGo[winnerSide]);
- clear_bit(&b, pawnToGo[loserSide]);
- b = queen_attacks_bb(winnerQSq, b);
+ if (Trace)
+ Tracing::terms[Us][Tracing::PASSED] = apply_weight(score, Weights[PassedPawns]);
- if ( (b & pos.pieces(KING, loserSide))
- ||(bit_is_set(b, loserQSq) && !bit_is_set(ei.attacked_by(loserSide), loserQSq)))
- ei.value += Sign[winnerSide] * make_score(0, UnstoppablePawnValue - Value(0x40 * (movesToGo[winnerSide]/2)));
- }
- }
+ // Add the scores to the middlegame 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() scores the most advanced among the passed and
+ // candidate pawns. In case opponent has no pieces but pawns, this is somewhat
+ // related to the possibility that pawns are unstoppable.
- void evaluate_trapped_bishop_a7h7(const Position& pos, Square s, Color us, EvalInfo &ei) {
+ Score evaluate_unstoppable_pawns(const Position& pos, Color us, const EvalInfo& ei) {
- assert(square_is_ok(s));
- assert(pos.piece_on(s) == piece_of_color_and_type(us, BISHOP));
+ Bitboard b = ei.pi->passed_pawns(us) | ei.pi->candidate_pawns(us);
- Square b6 = relative_square(us, (square_file(s) == FILE_A) ? SQ_B6 : SQ_G6);
- Square b8 = relative_square(us, (square_file(s) == FILE_A) ? SQ_B8 : SQ_G8);
+ if (!b || pos.non_pawn_material(~us))
+ return SCORE_ZERO;
- if ( pos.piece_on(b6) == piece_of_color_and_type(opposite_color(us), PAWN)
- && pos.see(s, b6) < 0
- && pos.see(s, b8) < 0)
- {
- ei.value -= Sign[us] * TrappedBishopA7H7Penalty;
- }
- }
-
-
- // 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 = piece_of_color_and_type(us, PAWN);
- Square b2, b3, c3;
-
- assert(Chess960);
- assert(square_is_ok(s));
- assert(pos.piece_on(s) == piece_of_color_and_type(us, BISHOP));
-
- if (square_file(s) == FILE_A)
- {
- b2 = relative_square(us, SQ_B2);
- b3 = relative_square(us, SQ_B3);
- c3 = relative_square(us, SQ_C3);
- }
- else
- {
- b2 = relative_square(us, SQ_G2);
- b3 = relative_square(us, SQ_G3);
- c3 = relative_square(us, SQ_F3);
- }
-
- if (pos.piece_on(b2) == pawn)
- {
- Score penalty;
-
- if (!pos.square_is_empty(b3))
- penalty = 2 * TrappedBishopA1H1Penalty;
- else if (pos.piece_on(c3) == pawn)
- penalty = TrappedBishopA1H1Penalty;
- else
- penalty = TrappedBishopA1H1Penalty / 2;
-
- ei.value -= Sign[us] * penalty;
- }
+ return Unstoppable * int(relative_rank(us, frontmost_sq(us, b)));
}
// available for minor pieces on the central four files on ranks 2--4. Safe
// squares one, two or three squares behind a friendly pawn are counted
// twice. Finally, the space bonus is scaled by a weight taken from the
- // material hash table.
- template<Color Us, bool HasPopCnt>
- void evaluate_space(const Position& pos, EvalInfo& ei) {
+ // material hash table. The aim is to improve play on game opening.
+ template<Color Us>
+ int evaluate_space(const Position& pos, const EvalInfo& ei) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
// Find the safe squares for our pieces inside the area defined by
- // SpaceMask[us]. A square is unsafe if it is attacked by an enemy
+ // SpaceMask[]. A square is unsafe if it is attacked by an enemy
// pawn, or if it is undefended and attacked by an enemy piece.
+ Bitboard safe = SpaceMask[Us]
+ & ~pos.pieces(Us, PAWN)
+ & ~ei.attackedBy[Them][PAWN]
+ & (ei.attackedBy[Us][ALL_PIECES] | ~ei.attackedBy[Them][ALL_PIECES]);
- Bitboard safeSquares = SpaceMask[Us]
- & ~pos.pieces(PAWN, Us)
- & ~ei.attacked_by(Them, PAWN)
- & ~(~ei.attacked_by(Us) & ei.attacked_by(Them));
+ // 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);
- // Find all squares which are at most three squares behind some friendly
- // pawn.
- Bitboard behindFriendlyPawns = pos.pieces(PAWN, Us);
- behindFriendlyPawns |= (Us == WHITE ? behindFriendlyPawns >> 8 : behindFriendlyPawns << 8);
- behindFriendlyPawns |= (Us == WHITE ? behindFriendlyPawns >> 16 : behindFriendlyPawns << 16);
+ // Since SpaceMask[Us] is fully on our half of the board
+ assert(unsigned(safe >> (Us == WHITE ? 32 : 0)) == 0);
- int space = count_1s_max_15<HasPopCnt>(safeSquares)
- + count_1s_max_15<HasPopCnt>(behindFriendlyPawns & safeSquares);
-
- ei.value += Sign[Us] * apply_weight(make_score(space * ei.mi->space_weight(), 0), Weights[Space]);
+ // Count safe + (behind & safe) with a single popcount
+ return popcount<Full>((Us == WHITE ? safe << 32 : safe >> 32) | (behind & safe));
}
- // apply_weight() applies an evaluation weight to a value trying to prevent overflow
+ // interpolate() interpolates between a middlegame and an endgame score,
+ // based on game phase. It also scales the return value by a ScaleFactor array.
- inline Score apply_weight(Score v, Score w) {
- return make_score((int(mg_value(v)) * mg_value(w)) / 0x100, (int(eg_value(v)) * eg_value(w)) / 0x100);
- }
+ Value interpolate(const Score& v, Phase ph, ScaleFactor sf) {
+
+ assert(-VALUE_INFINITE < mg_value(v) && mg_value(v) < VALUE_INFINITE);
+ assert(-VALUE_INFINITE < eg_value(v) && eg_value(v) < VALUE_INFINITE);
+ assert(PHASE_ENDGAME <= ph && ph <= PHASE_MIDGAME);
+ int eg = (eg_value(v) * int(sf)) / SCALE_FACTOR_NORMAL;
+ return Value((mg_value(v) * int(ph) + eg * int(PHASE_MIDGAME - ph)) / PHASE_MIDGAME);
+ }
- // 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.
+ // apply_weight() weights score v by score w trying to prevent overflow
+ Score apply_weight(Score v, const Weight& w) {
- Value scale_by_game_phase(const Score& v, Phase ph, const ScaleFactor sf[]) {
+ return make_score(mg_value(v) * w.mg / 256, eg_value(v) * w.eg / 256);
+ }
- 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);
+ // weight_option() computes the value of an evaluation weight, by combining
+ // two UCI-configurable weights (midgame and endgame) with an internal weight.
- Value ev = apply_scale_factor(eg_value(v), sf[(eg_value(v) > Value(0) ? WHITE : BLACK)]);
+ Weight weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight) {
- int result = (mg_value(v) * ph + ev * (128 - ph)) / 128;
- return Value(result & ~(GrainSize - 1));
+ Weight w = { Options[mgOpt] * mg_value(internalWeight) / 100,
+ Options[egOpt] * eg_value(internalWeight) / 100 };
+ return w;
}
- // weight_option() computes the value of an evaluation weight, by combining
- // two UCI-configurable weights (midgame and endgame) with an internal weight.
+ // Tracing function definitions
- Score weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight) {
+ double Tracing::to_cp(Value v) { return double(v) / PawnValueEg; }
- Score uciWeight = make_score(get_option_value_int(mgOpt), get_option_value_int(egOpt));
+ void Tracing::add_term(int idx, Score wScore, Score bScore) {
- // Convert to integer to prevent overflow
- int mg = mg_value(uciWeight);
- int eg = eg_value(uciWeight);
+ terms[WHITE][idx] = wScore;
+ terms[BLACK][idx] = bScore;
+ }
- mg = (mg * 0x100) / 100;
- eg = (eg * 0x100) / 100;
- mg = (mg * mg_value(internalWeight)) / 0x100;
- eg = (eg * eg_value(internalWeight)) / 0x100;
- return make_score(mg, eg);
+ void Tracing::format_row(std::stringstream& ss, const char* name, int idx) {
+
+ Score wScore = terms[WHITE][idx];
+ Score bScore = terms[BLACK][idx];
+
+ switch (idx) {
+ case PST: case IMBALANCE: case PAWN: case TOTAL:
+ ss << std::setw(20) << name << " | --- --- | --- --- | "
+ << std::setw(5) << to_cp(mg_value(wScore - bScore)) << " "
+ << std::setw(5) << to_cp(eg_value(wScore - bScore)) << " \n";
+ break;
+ default:
+ ss << std::setw(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::setw(5) << to_cp(mg_value(wScore - bScore)) << " "
+ << std::setw(5) << to_cp(eg_value(wScore - bScore)) << " \n";
+ }
}
- // init_safety() initizes the king safety evaluation, based on UCI
- // parameters. It is called from read_weights().
+ std::string Tracing::do_trace(const Position& pos) {
- void init_safety() {
+ std::memset(terms, 0, sizeof(terms));
- int maxSlope = 30;
- int peak = 0x500;
- double a = 0.4;
- double b = 0.0;
- Value t[100];
+ Value v = do_evaluate<true>(pos);
+ v = pos.side_to_move() == WHITE ? v : -v; // White's point of view
- // First setup the base table
- for (int i = 0; i < 100; i++)
- {
- if (i < b)
- t[i] = Value(0);
- else
- t[i] = Value((int)(a * (i - b) * (i - b)));
- }
+ std::stringstream ss;
+ ss << std::showpoint << std::noshowpos << std::fixed << std::setprecision(2)
+ << " Eval term | White | Black | Total \n"
+ << " | MG EG | MG EG | MG EG \n"
+ << "---------------------+-------------+-------------+-------------\n";
- for (int i = 1; i < 100; i++)
- {
- if (t[i] - t[i - 1] > maxSlope)
- t[i] = t[i - 1] + Value(maxSlope);
+ format_row(ss, "Material, PST, Tempo", PST);
+ format_row(ss, "Material imbalance", IMBALANCE);
+ format_row(ss, "Pawns", PAWN);
+ format_row(ss, "Knights", KNIGHT);
+ format_row(ss, "Bishops", BISHOP);
+ format_row(ss, "Rooks", ROOK);
+ format_row(ss, "Queens", QUEEN);
+ format_row(ss, "Mobility", MOBILITY);
+ format_row(ss, "King safety", KING);
+ format_row(ss, "Threats", THREAT);
+ format_row(ss, "Passed pawns", PASSED);
+ format_row(ss, "Space", SPACE);
- if (t[i] > Value(peak))
- t[i] = Value(peak);
- }
+ ss << "---------------------+-------------+-------------+-------------\n";
+ format_row(ss, "Total", TOTAL);
+
+ ss << "\nTotal Evaluation: " << to_cp(v) << " (white side)\n";
- // Then apply the weights and get the final KingDangerTable[] array
- for (Color c = WHITE; c <= BLACK; c++)
- for (int i = 0; i < 100; i++)
- KingDangerTable[c][i] = apply_weight(make_score(t[i], 0), Weights[KingDangerUs + c]);
+ return ss.str();
}
}
projects / stockfish / blobdiff