X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fevaluate.cpp;h=057fd70c8216ec5fd4cae5d212b76d760a5ca0fc;hb=8a7876d48d4360d14d918c1ff444b5d6eb0382de;hp=05c4c1119bb61eb0a6242c3072509a95cac9c14b;hpb=a10487b07453a13c8ef0c445cd34bb06b99b3760;p=stockfish
diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 05c4c111..057fd70c 100644
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -1,7 +1,7 @@
/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
@@ -17,8 +17,8 @@
along with this program. If not, see .
*/
+#include
#include
-#include
#include
#include
@@ -27,7 +27,6 @@
#include "material.h"
#include "pawns.h"
#include "thread.h"
-#include "ucioption.h"
namespace {
@@ -36,87 +35,93 @@ namespace {
struct EvalInfo {
// Pointers to material and pawn hash table entries
- MaterialInfo* mi;
- PawnInfo* pi;
+ 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][0] contains
- // all squares attacked by the given color.
- Bitboard attackedBy[2][8];
+ // 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];
- // kingZone[color] is the zone around the enemy king which is considered
+ // 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, kingZone[WHITE] is a bitboard containing the squares f8, h8,
+ // is on g8, kingRing[BLACK] is a bitboard containing the squares f8, h8,
// f7, g7, h7, f6, g6 and h6.
- Bitboard kingZone[2];
+ Bitboard kingRing[COLOR_NB];
// kingAttackersCount[color] is the number of pieces of the given color
- // which attack a square in the kingZone of the enemy king.
- int kingAttackersCount[2];
+ // 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 kingZone of the enemy king. 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];
+ 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[2];
+ int kingAdjacentZoneAttacksCount[COLOR_NB];
+
+ Bitboard pinnedPieces[COLOR_NB];
};
- // Evaluation grain size, must be a power of 2
- const int GrainSize = 8;
+ namespace Tracing {
- // Evaluation weights, initialized from UCI options
- enum { Mobility, PawnStructure, PassedPawns, Space, KingDangerUs, KingDangerThem };
- Score Weights[6];
+ enum Terms { // First 8 entries are for PieceType
+ MATERIAL = 8, IMBALANCE, MOBILITY, THREAT, PASSED, SPACE, TOTAL, TERMS_NB
+ };
- typedef Value V;
- #define S(mg, eg) make_score(mg, eg)
+ Score scores[COLOR_NB][TERMS_NB];
+ EvalInfo ei;
+ ScaleFactor sf;
- // Internal evaluation weights. These are applied on top of the evaluation
- // weights read from UCI parameters. The purpose is to be able to change
- // the evaluation weights while keeping the default values of the UCI
- // parameters at 100, which looks prettier.
- //
- // Values modified by Joona Kiiski
- const Score WeightsInternal[] = {
- S(248, 271), S(233, 201), S(252, 259), S(46, 0), S(247, 0), S(259, 0)
+ double to_cp(Value v);
+ void write(int idx, Color c, Score s);
+ void write(int idx, Score w, Score b = SCORE_ZERO);
+ void print(std::stringstream& ss, const char* name, int idx);
+ std::string do_trace(const Position& pos);
+ }
+
+ // Evaluation weights, indexed by evaluation term
+ enum { Mobility, PawnStructure, PassedPawns, Space, KingSafety };
+ const struct Weight { int mg, eg; } Weights[] = {
+ {289, 344}, {233, 201}, {221, 273}, {46, 0}, {318, 0}
};
- // 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.
+ typedef Value V;
+ #define S(mg, eg) make_score(mg, eg)
+
+ // 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(-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) }
+ {}, {},
+ { S(-65,-50), S(-42,-30), S(-9,-10), S( 3, 0), S(15, 10), S(27, 20), // Knights
+ S( 37, 28), S( 42, 31), S(44, 33) },
+ { S(-52,-47), S(-28,-23), S( 6, 1), S(20, 15), S(34, 29), S(48, 43), // Bishops
+ S( 60, 55), S( 68, 63), S(74, 68), S(77, 72), S(80, 75), S(82, 77),
+ S( 84, 79), S( 86, 81) },
+ { S(-47,-53), S(-31,-26), S(-5, 0), S( 1, 16), S( 7, 32), S(13, 48), // Rooks
+ S( 18, 64), S( 22, 80), S(26, 96), S(29,109), S(31,115), S(33,119),
+ S( 35,122), S( 36,123), S(37,124) },
+ { S(-42,-40), S(-28,-23), S(-5, -7), S( 0, 0), S( 6, 10), S(11, 19), // Queens
+ S( 13, 29), S( 18, 38), S(20, 40), S(21, 41), S(22, 41), S(22, 41),
+ S( 22, 41), S( 23, 41), S(24, 41), S(25, 41), S(25, 41), S(25, 41),
+ S( 25, 41), S( 25, 41), S(25, 41), S(25, 41), S(25, 41), S(25, 41),
+ S( 25, 41), S( 25, 41), S(25, 41), S(25, 41) }
};
- // 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
+ // 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),
@@ -132,612 +137,320 @@ namespace {
V(0), V(5), V(8), V(8), V(8), V(8), V(5), V(0) }
};
- // 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(-1, 29), S(15, 49), S(15, 49), S( 0, 0), S(24, 49) }, // ROOK
- { S(0, 0), S(15, 39), S(15, 39), S(15, 39), S(15, 39), S( 0, 0) } // QUEEN
+ // Threat[attacking][attacked] contains bonuses according to which piece
+ // type attacks which one.
+ const Score Threat[][PIECE_TYPE_NB] = {
+ { S(0, 0), S(0, 38), S(32, 45), S(32, 45), S(41,100), S(35,104) }, // Minor
+ { S(0, 0), S(7, 28), S(20, 49), S(20, 49), S(8 , 42), S(23, 44) } // Major
};
- // ThreatedByPawnPenalty[PieceType] contains a penalty according to which
- // piece type is attacked by an enemy pawn.
- const Score ThreatedByPawnPenalty[] = {
- S(0, 0), S(0, 0), S(56, 70), S(56, 70), S(76, 99), S(86, 118)
+ // 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(80, 119), S(80, 119), S(117, 199), S(127, 218)
};
- #undef S
-
- // Rooks and queens on the 7th rank (modified by Joona Kiiski)
- const Score RookOn7thBonus = make_score(47, 98);
- const Score QueenOn7thBonus = make_score(27, 54);
-
- // Rooks on open files (modified by Joona Kiiski)
- const Score RookOpenFileBonus = make_score(43, 43);
- const Score RookHalfOpenFileBonus = make_score(19, 19);
-
- // Penalty for rooks trapped inside a friendly king which has lost the
- // right to castle.
- const Value TrappedRookPenalty = Value(180);
+ // Assorted bonuses and penalties used by evaluation
+ const Score KingOnOne = S(2 , 58);
+ const Score KingOnMany = S(6 ,125);
+ const Score RookOnPawn = S(10, 28);
+ const Score RookOpenFile = S(43, 21);
+ const Score RookSemiOpenFile = S(19, 10);
+ const Score BishopPawns = S( 8, 12);
+ const Score MinorBehindPawn = S(16, 0);
+ const Score TrappedRook = S(92, 0);
+ const Score Unstoppable = S( 0, 20);
+ const Score Hanging = S(23, 20);
// Penalty for a bishop on a1/h1 (a8/h8 for black) which is trapped by
// a friendly pawn on b2/g2 (b7/g7 for black). This can obviously only
// happen in Chess960 games.
- const Score TrappedBishopA1H1Penalty = make_score(100, 100);
+ const Score TrappedBishopA1H1 = S(50, 50);
+
+ #undef S
- // The SpaceMask[Color] contains the area of the board which is considered
- // by the space evaluation. In the middle game, each side is given a bonus
+ // SpaceMask[Color] contains the area of the board which is considered
+ // by the space evaluation. In the middlegame, each side is given a bonus
// based on how many squares inside this area are safe and available for
// friendly minor pieces.
const Bitboard SpaceMask[] = {
- (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)
+ (FileCBB | FileDBB | FileEBB | FileFBB) & (Rank2BB | Rank3BB | Rank4BB),
+ (FileCBB | FileDBB | FileEBB | FileFBB) & (Rank7BB | Rank6BB | Rank5BB)
};
// 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[].
+ // 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 };
// 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
- };
-
- // 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
- };
-
- // Function prototypes
- template
- Value do_evaluate(const Position& pos, Value& margin);
-
- template
- void init_eval_info(const Position& pos, EvalInfo& ei);
-
- template
- Score evaluate_pieces_of_color(const Position& pos, EvalInfo& ei, Score& mobility);
-
- template
- Score evaluate_king(const Position& pos, EvalInfo& ei, Value margins[]);
-
- template
- Score evaluate_threats(const Position& pos, EvalInfo& ei);
-
- template
- int evaluate_space(const Position& pos, EvalInfo& ei);
-
- template
- Score evaluate_passed_pawns(const Position& pos, EvalInfo& ei);
-
- template
- Score evaluate_unstoppable_pawns(const Position& pos, EvalInfo& ei);
-
- inline Score apply_weight(Score v, Score weight);
- Value scale_by_game_phase(const Score& v, Phase ph, ScaleFactor sf);
- Score weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight);
- void init_safety();
- double to_cp(Value v);
- void trace_add(int idx, Score term_w, Score term_b = SCORE_ZERO);
-}
-
-
-/// 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, Value& margin) {
-
- return CpuHasPOPCNT ? do_evaluate(pos, margin)
- : do_evaluate(pos, margin);
-}
-
-namespace {
-
-template
-Value do_evaluate(const Position& pos, Value& margin) {
-
- EvalInfo ei;
- Value margins[2];
- Score score, mobilityWhite, mobilityBlack;
-
- assert(pos.is_ok());
- assert(pos.thread() >= 0 && pos.thread() < MAX_THREADS);
- assert(!pos.in_check());
-
- // Initialize score by reading the incrementally updated scores included
- // in the position object (material + piece square tables).
- score = pos.value();
-
- // 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;
-
- // Probe the material hash table
- ei.mi = Threads[pos.thread()].materialTable.get_material_info(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);
- }
-
- // Probe the pawn hash table
- ei.pi = Threads[pos.thread()].pawnTable.get_pawn_info(pos);
- score += apply_weight(ei.pi->pawns_value(), Weights[PawnStructure]);
-
- // Initialize attack and king safety bitboards
- init_eval_info(pos, ei);
- init_eval_info(pos, ei);
-
- // Evaluate pieces and mobility
- score += evaluate_pieces_of_color(pos, ei, mobilityWhite)
- - evaluate_pieces_of_color(pos, ei, mobilityBlack);
-
- score += apply_weight(mobilityWhite - mobilityBlack, Weights[Mobility]);
-
- // Evaluate kings after all other pieces because we need complete attack
- // information when computing the king safety evaluation.
- score += evaluate_king(pos, ei, margins)
- - evaluate_king(pos, ei, margins);
-
- // Evaluate tactical threats, we need full attack information including king
- score += evaluate_threats(pos, ei)
- - evaluate_threats(pos, ei);
-
- // Evaluate passed pawns, we need full attack information including king
- score += evaluate_passed_pawns(pos, ei)
- - evaluate_passed_pawns(pos, ei);
-
- // If one side has only a king, check whether exists any unstoppable passed pawn
- if (!pos.non_pawn_material(WHITE) || !pos.non_pawn_material(BLACK))
- score += evaluate_unstoppable_pawns(pos, ei);
-
- // Evaluate space for both sides, only in middle-game.
- if (ei.mi->space_weight())
- {
- int s = evaluate_space(pos, ei) - evaluate_space(pos, ei);
- score += apply_weight(make_score(s * ei.mi->space_weight(), 0), Weights[Space]);
+ const int QueenContactCheck = 24;
+ const int RookContactCheck = 16;
+ const int QueenCheck = 12;
+ const int RookCheck = 8;
+ const int BishopCheck = 2;
+ const int KnightCheck = 3;
+
+ // KingDanger[attackUnits] contains the actual king danger weighted
+ // scores, indexed by a calculated integer number.
+ Score KingDanger[128];
+
+ const int ScalePawnSpan[2] = { 38, 56 };
+
+ // apply_weight() weighs score 'v' by weight 'w' trying to prevent overflow
+ Score apply_weight(Score v, const Weight& w) {
+ return make_score(mg_value(v) * w.mg / 256, eg_value(v) * w.eg / 256);
}
- // 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_colored_bishops()
- && sf == SCALE_FACTOR_NORMAL)
- {
- // Only the two bishops ?
- if ( pos.non_pawn_material(WHITE) == BishopValueMidgame
- && pos.non_pawn_material(BLACK) == BishopValueMidgame)
- {
- // Check for KBP vs KB with only a single pawn that is almost
- // certainly a draw or at least two pawns.
- bool one_pawn = (pos.piece_count(WHITE, PAWN) + pos.piece_count(BLACK, PAWN) == 1);
- sf = one_pawn ? ScaleFactor(8) : ScaleFactor(32);
- }
- else
- // Endgame with opposite-colored bishops, but also other pieces. Still
- // a bit drawish, but not as drawish as with only the two bishops.
- sf = ScaleFactor(50);
- }
-
- // Interpolate between the middle game and the endgame score
- margin = margins[pos.side_to_move()];
- Value v = scale_by_game_phase(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.value());
- trace_add(IMBALANCE, ei.mi->material_value());
- trace_add(PAWN, apply_weight(ei.pi->pawns_value(), Weights[PawnStructure]));
- trace_add(MOBILITY, apply_weight(mobilityWhite, Weights[Mobility]), apply_weight(mobilityBlack, Weights[Mobility]));
- trace_add(THREAT, evaluate_threats(pos, ei), evaluate_threats(pos, ei));
- trace_add(PASSED, evaluate_passed_pawns(pos, ei), evaluate_passed_pawns(pos, ei));
- trace_add(UNSTOPPABLE, evaluate_unstoppable_pawns(pos, ei));
- Score w = make_score(ei.mi->space_weight() * evaluate_space(pos, ei), 0);
- Score b = make_score(ei.mi->space_weight() * evaluate_space(pos, ei), 0);
- trace_add(SPACE, apply_weight(w, Weights[Space]), apply_weight(b, Weights[Space]));
- trace_add(TOTAL, score);
- TraceStream << "\nUncertainty margin: White: " << to_cp(margins[WHITE])
- << ", Black: " << to_cp(margins[BLACK])
- << "\nScaling: " << std::noshowpos
- << std::setw(6) << 100.0 * ei.mi->game_phase() / 128.0 << "% MG, "
- << std::setw(6) << 100.0 * (1.0 - ei.mi->game_phase() / 128.0) << "% * "
- << std::setw(6) << (100.0 * sf) / SCALE_FACTOR_NORMAL << "% EG.\n"
- << "Total evaluation: " << to_cp(v);
- }
-
- return pos.side_to_move() == WHITE ? v : -v;
-}
-
-} // namespace
-
-
-/// read_weights() reads evaluation weights from the corresponding UCI parameters
-
-void read_evaluation_uci_options(Color us) {
-
- // King safety is asymmetrical. Our king danger level is weighted by
- // "Cowardice" UCI parameter, instead the opponent one by "Aggressiveness".
- const int kingDangerUs = (us == WHITE ? KingDangerUs : KingDangerThem);
- const int kingDangerThem = (us == WHITE ? KingDangerThem : KingDangerUs);
-
- Weights[Mobility] = weight_option("Mobility (Middle Game)", "Mobility (Endgame)", WeightsInternal[Mobility]);
- Weights[PawnStructure] = weight_option("Pawn Structure (Middle Game)", "Pawn Structure (Endgame)", WeightsInternal[PawnStructure]);
- Weights[PassedPawns] = weight_option("Passed Pawns (Middle Game)", "Passed Pawns (Endgame)", WeightsInternal[PassedPawns]);
- Weights[Space] = weight_option("Space", "Space", WeightsInternal[Space]);
- Weights[kingDangerUs] = weight_option("Cowardice", "Cowardice", WeightsInternal[KingDangerUs]);
- Weights[kingDangerThem] = weight_option("Aggressiveness", "Aggressiveness", WeightsInternal[KingDangerThem]);
-
- // If running in analysis mode, make sure we use symmetrical king safety. We do this
- // by replacing both Weights[kingDangerUs] and Weights[kingDangerThem] by their average.
- if (Options["UCI_AnalyseMode"].value())
- Weights[kingDangerUs] = Weights[kingDangerThem] = (Weights[kingDangerUs] + Weights[kingDangerThem]) / 2;
-
- init_safety();
-}
-
-
-namespace {
// init_eval_info() initializes king bitboards for given color adding
// pawn attacks. To be done at the beginning of the evaluation.
- template
+ template
void init_eval_info(const Position& pos, EvalInfo& ei) {
- const BitCountType Max15 = HasPopCnt ? CNT_POPCNT : CpuIs64Bit ? CNT64_MAX15 : CNT32_MAX15;
- const Color Them = (Us == WHITE ? BLACK : WHITE);
+ const Color Them = (Us == WHITE ? BLACK : WHITE);
+ const Square Down = (Us == WHITE ? DELTA_S : DELTA_N);
+
+ ei.pinnedPieces[Us] = pos.pinned_pieces(Us);
Bitboard b = ei.attackedBy[Them][KING] = pos.attacks_from(pos.king_square(Them));
- ei.attackedBy[Us][PAWN] = ei.pi->pawn_attacks(Us);
+ ei.attackedBy[Us][ALL_PIECES] = 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) >= QueenValueMidgame + RookValueMidgame)
+ if (pos.non_pawn_material(Us) > QueenValueMg + PawnValueMg)
{
- ei.kingZone[Us] = (b | (Us == WHITE ? b >> 8 : b << 8));
+ ei.kingRing[Them] = b | shift_bb(b);
b &= ei.attackedBy[Us][PAWN];
- ei.kingAttackersCount[Us] = b ? count_1s(b) / 2 : 0;
+ ei.kingAttackersCount[Us] = b ? popcount(b) : 0;
ei.kingAdjacentZoneAttacksCount[Us] = ei.kingAttackersWeight[Us] = 0;
- } else
- ei.kingZone[Us] = ei.kingAttackersCount[Us] = 0;
+ }
+ else
+ ei.kingRing[Them] = ei.kingAttackersCount[Us] = 0;
}
- // evaluate_outposts() evaluates bishop and knight outposts squares
+ // evaluate_outpost() evaluates bishop and knight outpost squares
- template
- Score evaluate_outposts(const Position& pos, EvalInfo& ei, Square s) {
+ template
+ Score evaluate_outpost(const Position& pos, const EvalInfo& ei, Square s) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
- assert (Piece == BISHOP || Piece == KNIGHT);
+ assert (Pt == BISHOP || Pt == KNIGHT);
// Initial bonus based on square
- Value bonus = OutpostBonus[Piece == BISHOP][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;
}
- return make_score(bonus, bonus);
+
+ return make_score(bonus * 2, bonus / 2);
}
- // 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
- Score evaluate_pieces(const Position& pos, EvalInfo& ei, Score& mobility, Bitboard mobilityArea) {
+ template
+ Score evaluate_pieces(const Position& pos, EvalInfo& ei, Score* mobility, Bitboard* mobilityArea) {
Bitboard b;
- Square s, ksq;
- int mob;
- File f;
+ Square s;
Score score = SCORE_ZERO;
- const BitCountType Full = HasPopCnt ? CNT_POPCNT : CpuIs64Bit ? CNT64 : CNT32;
- const BitCountType Max15 = HasPopCnt ? CNT_POPCNT : CpuIs64Bit ? CNT64_MAX15 : CNT32_MAX15;
+ const PieceType NextPt = (Us == WHITE ? Pt : PieceType(Pt + 1));
const Color Them = (Us == WHITE ? BLACK : WHITE);
- const Square* ptr = pos.piece_list_begin(Us, Piece);
+ const Square* pl = pos.list(Us);
- ei.attackedBy[Us][Piece] = EmptyBoardBB;
+ ei.attackedBy[Us][Pt] = 0;
- while ((s = *ptr++) != SQ_NONE)
+ while ((s = *pl++) != SQ_NONE)
{
// Find attacked squares, including x-ray attacks for bishops and rooks
- if (Piece == KNIGHT || Piece == QUEEN)
- b = pos.attacks_from(s);
- else if (Piece == BISHOP)
- b = bishop_attacks_bb(s, pos.occupied_squares() & ~pos.pieces(QUEEN, Us));
- else if (Piece == ROOK)
- b = rook_attacks_bb(s, pos.occupied_squares() & ~pos.pieces(ROOK, QUEEN, Us));
- else
- assert(false);
+ b = Pt == BISHOP ? attacks_bb(s, pos.pieces() ^ pos.pieces(Us, QUEEN))
+ : Pt == ROOK ? attacks_bb< ROOK>(s, pos.pieces() ^ pos.pieces(Us, ROOK, QUEEN))
+ : pos.attacks_from(s);
+
+ if (ei.pinnedPieces[Us] & s)
+ b &= LineBB[pos.king_square(Us)][s];
- // Update attack info
- ei.attackedBy[Us][Piece] |= b;
+ ei.attackedBy[Us][ALL_PIECES] |= ei.attackedBy[Us][Pt] |= b;
- // King attacks
- if (b & ei.kingZone[Us])
+ if (b & ei.kingRing[Them])
{
ei.kingAttackersCount[Us]++;
- ei.kingAttackersWeight[Us] += KingAttackWeights[Piece];
- Bitboard bb = (b & ei.attackedBy[Them][KING]);
+ ei.kingAttackersWeight[Us] += KingAttackWeights[Pt];
+ Bitboard bb = b & ei.attackedBy[Them][KING];
if (bb)
- ei.kingAdjacentZoneAttacksCount[Us] += count_1s(bb);
+ ei.kingAdjacentZoneAttacksCount[Us] += popcount(bb);
}
- // Mobility
- mob = (Piece != QUEEN ? count_1s(b & mobilityArea)
- : count_1s(b & mobilityArea));
+ if (Pt == QUEEN)
+ b &= ~( ei.attackedBy[Them][KNIGHT]
+ | ei.attackedBy[Them][BISHOP]
+ | ei.attackedBy[Them][ROOK]);
- mobility += MobilityBonus[Piece][mob];
+ int mob = Pt != QUEEN ? popcount(b & mobilityArea[Us])
+ : popcount(b & mobilityArea[Us]);
- // Decrease score if we are attacked by an enemy pawn. Remaining part
- // of threat evaluation must be done later when we have full attack info.
- if (bit_is_set(ei.attackedBy[Them][PAWN], s))
- score -= ThreatedByPawnPenalty[Piece];
+ mobility[Us] += MobilityBonus[Pt][mob];
- // Bishop and knight outposts squares
- if ((Piece == BISHOP || Piece == KNIGHT) && pos.square_is_weak(s, Us))
- score += evaluate_outposts(pos, ei, s);
+ // Decrease score if we are attacked by an enemy pawn. The remaining part
+ // of threat evaluation must be done later when we have full attack info.
+ if (ei.attackedBy[Them][PAWN] & s)
+ score -= ThreatenedByPawn[Pt];
- // Queen or rook on 7th rank
- if ( (Piece == ROOK || Piece == QUEEN)
- && relative_rank(Us, s) == RANK_7
- && relative_rank(Us, pos.king_square(Them)) == RANK_8)
+ if (Pt == BISHOP || Pt == KNIGHT)
{
- score += (Piece == ROOK ? RookOn7thBonus : QueenOn7thBonus);
+ // Penalty for bishop with same colored pawns
+ if (Pt == BISHOP)
+ score -= BishopPawns * ei.pi->pawns_on_same_color_squares(Us, s);
+
+ // Bishop and knight outpost square
+ if (!(pos.pieces(Them, PAWN) & pawn_attack_span(Us, s)))
+ score += evaluate_outpost(pos, ei, s);
+
+ // Bishop or knight behind a pawn
+ if ( relative_rank(Us, s) < RANK_5
+ && (pos.pieces(PAWN) & (s + pawn_push(Us))))
+ score += MinorBehindPawn;
}
- // Special extra evaluation for bishops
- if (Piece == BISHOP && pos.is_chess960())
+ if (Pt == ROOK)
{
- // 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))
+ // Rook piece attacking enemy pawns on the same rank/file
+ if (relative_rank(Us, s) >= RANK_5)
{
- Square d = pawn_push(Us) + (square_file(s) == FILE_A ? DELTA_E : DELTA_W);
- if (pos.piece_on(s + d) == make_piece(Us, PAWN))
- {
- if (!pos.square_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;
- }
+ Bitboard pawns = pos.pieces(Them, PAWN) & PseudoAttacks[ROOK][s];
+ if (pawns)
+ score += popcount(pawns) * RookOnPawn;
}
- }
- // 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))
- {
- if (ei.pi->file_is_half_open(Them, f))
- score += RookOpenFileBonus;
- else
- score += RookHalfOpenFileBonus;
- }
+ // Give a bonus for a rook on a open or semi-open file
+ if (ei.pi->semiopen_file(Us, file_of(s)))
+ score += ei.pi->semiopen_file(Them, file_of(s)) ? RookOpenFile : RookSemiOpenFile;
- // 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))
+ if (mob > 3 || ei.pi->semiopen_file(Us, file_of(s)))
continue;
- ksq = pos.king_square(Us);
+ Square ksq = pos.king_square(Us);
- if ( square_file(ksq) >= FILE_E
- && square_file(s) > square_file(ksq)
- && (relative_rank(Us, ksq) == RANK_1 || square_rank(ksq) == square_rank(s)))
- {
- // Is there a half-open file between the king and the edge of the board?
- if (!ei.pi->has_open_file_to_right(Us, square_file(ksq)))
- score -= 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)))
- score -= make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2
- : (TrappedRookPenalty - mob * 16), 0);
- }
+ // Penalize rooks which are trapped by a king. Penalize more if the
+ // king has lost its castling capability.
+ if ( ((file_of(ksq) < FILE_E) == (file_of(s) < file_of(ksq)))
+ && (rank_of(ksq) == rank_of(s) || relative_rank(Us, ksq) == RANK_1)
+ && !ei.pi->semiopen_side(Us, file_of(ksq), file_of(s) < file_of(ksq)))
+ score -= (TrappedRook - make_score(mob * 22, 0)) * (1 + !pos.can_castle(Us));
+ }
+
+ // 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;
}
}
if (Trace)
- TracedScores[Us][Piece] = score;
+ Tracing::write(Pt, Us, score);
- return score;
+ return score - evaluate_pieces(pos, ei, mobility, mobilityArea);
}
+ template<>
+ Score evaluate_pieces(const Position&, EvalInfo&, Score*, Bitboard*) { return SCORE_ZERO; }
+ template<>
+ Score evaluate_pieces(const Position&, EvalInfo&, Score*, Bitboard*) { return SCORE_ZERO; }
- // evaluate_threats<>() assigns bonuses according to the type of attacking piece
- // and the type of attacked one.
- template
- Score evaluate_threats(const Position& pos, EvalInfo& ei) {
+ // evaluate_king() assigns bonuses and penalties to a king of a given color
- const Color Them = (Us == WHITE ? BLACK : WHITE);
-
- Bitboard b;
- Score score = SCORE_ZERO;
-
- // Enemy pieces not defended by a pawn and under our attack
- Bitboard weakEnemies = pos.pieces_of_color(Them)
- & ~ei.attackedBy[Them][PAWN]
- & ei.attackedBy[Us][0];
- if (!weakEnemies)
- return SCORE_ZERO;
-
- // 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];
- }
- return score;
- }
-
-
- // evaluate_pieces_of_color<>() assigns bonuses and penalties to all the
- // pieces of a given color.
-
- template
- Score evaluate_pieces_of_color(const Position& pos, EvalInfo& ei, Score& mobility) {
+ template
+ Score evaluate_king(const Position& pos, const EvalInfo& ei) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
- Score score = mobility = SCORE_ZERO;
-
- // Do not include in mobility squares protected by enemy pawns or occupied by our pieces
- const Bitboard mobilityArea = ~(ei.attackedBy[Them][PAWN] | pos.pieces_of_color(Us));
-
- score += evaluate_pieces(pos, ei, mobility, mobilityArea);
- score += evaluate_pieces(pos, ei, mobility, mobilityArea);
- score += evaluate_pieces(pos, ei, mobility, mobilityArea);
- score += evaluate_pieces(pos, ei, mobility, mobilityArea);
-
- // Sum up all attacked squares
- ei.attackedBy[Us][0] = ei.attackedBy[Us][PAWN] | ei.attackedBy[Us][KNIGHT]
- | ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK]
- | ei.attackedBy[Us][QUEEN] | ei.attackedBy[Us][KING];
- return score;
- }
-
-
- // evaluate_king<>() assigns bonuses and penalties to a king of a given color
-
- template
- Score evaluate_king(const Position& pos, EvalInfo& ei, Value margins[]) {
-
- const BitCountType Max15 = HasPopCnt ? CNT_POPCNT : CpuIs64Bit ? CNT64_MAX15 : CNT32_MAX15;
- const Color Them = (Us == WHITE ? BLACK : WHITE);
-
Bitboard undefended, b, b1, b2, safe;
int attackUnits;
const Square ksq = pos.king_square(Us);
- // King shelter
- Score score = ei.pi->king_shelter(pos, ksq);
+ // King shelter and enemy pawns storm
+ Score score = ei.pi->king_safety(pos, ksq);
- // King safety. This is quite complicated, and is almost certainly far
- // from optimally tuned.
- if ( ei.kingAttackersCount[Them] >= 2
- && ei.kingAdjacentZoneAttacksCount[Them])
+ // Main king safety evaluation
+ if (ei.kingAttackersCount[Them])
{
- // Find the attacked squares around the king which has no defenders
+ // Find the attacked squares around the king which have no defenders
// apart from the king itself
- undefended = ei.attackedBy[Them][0] & ei.attackedBy[Us][KING];
- undefended &= ~( ei.attackedBy[Us][PAWN] | ei.attackedBy[Us][KNIGHT]
+ undefended = ei.attackedBy[Them][ALL_PIECES]
+ & ei.attackedBy[Us][KING]
+ & ~( ei.attackedBy[Us][PAWN] | ei.attackedBy[Us][KNIGHT]
| ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK]
| ei.attackedBy[Us][QUEEN]);
// Initialize the 'attackUnits' variable, which is used later on as an
- // index to the KingDangerTable[] array. The initial value is based on
- // the number and types of the enemy's attacking pieces, the number of
- // attacked and undefended squares around our king, the square of the
- // king, and the quality of the pawn shelter.
- attackUnits = Min(25, (ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) / 2)
- + 3 * (ei.kingAdjacentZoneAttacksCount[Them] + count_1s(undefended))
- + InitKingDanger[relative_square(Us, ksq)]
- - mg_value(ei.pi->king_shelter(pos, ksq)) / 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_of_color(Them);
+ // index to the KingDanger[] array. The initial value is based on the
+ // number and types of the enemy's attacking pieces, the number of
+ // attacked and undefended squares around our king and the quality of
+ // the pawn shelter (current 'score' value).
+ attackUnits = std::min(20, (ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) / 2)
+ + 3 * (ei.kingAdjacentZoneAttacksCount[Them] + popcount(undefended))
+ + 2 * (ei.pinnedPieces[Us] != 0)
+ - mg_value(score) / 32
+ - !pos.count(Them) * 15;
+
+ // Analyse the enemy's safe queen contact checks. Firstly, find the
+ // undefended squares around the king that are attacked by the enemy's
+ // queen...
+ b = undefended & ei.attackedBy[Them][QUEEN] & ~pos.pieces(Them);
if (b)
{
- // ...then remove squares not supported by another enemy piece
+ // ...and then remove squares not supported by another enemy piece
b &= ( ei.attackedBy[Them][PAWN] | ei.attackedBy[Them][KNIGHT]
| ei.attackedBy[Them][BISHOP] | ei.attackedBy[Them][ROOK]);
+
if (b)
- attackUnits += QueenContactCheckBonus
- * count_1s(b)
- * (Them == pos.side_to_move() ? 2 : 1);
+ attackUnits += QueenContactCheck * popcount(b);
}
- // 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_of_color(Them);
+ // 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 rook gives check
- b &= RookPseudoAttacks[ksq];
+ // Consider only squares where the enemy's rook gives check
+ b &= PseudoAttacks[ROOK][ksq];
if (b)
{
- // ...then remove squares not supported by another enemy piece
+ // ...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 += RookContactCheckBonus
- * count_1s(b)
- * (Them == pos.side_to_move() ? 2 : 1);
+ attackUnits += RookContactCheck * popcount(b);
}
- // Analyse enemy's safe distance checks for sliders and knights
- safe = ~(pos.pieces_of_color(Them) | ei.attackedBy[Us][0]);
+ // Analyse the enemy's safe distance checks for sliders and knights
+ safe = ~(pos.pieces(Them) | ei.attackedBy[Us][ALL_PIECES]);
b1 = pos.attacks_from(ksq) & safe;
b2 = pos.attacks_from(ksq) & safe;
@@ -745,302 +458,200 @@ namespace {
// Enemy queen safe checks
b = (b1 | b2) & ei.attackedBy[Them][QUEEN];
if (b)
- attackUnits += QueenCheckBonus * count_1s(b);
+ attackUnits += QueenCheck * popcount(b);
// Enemy rooks safe checks
b = b1 & ei.attackedBy[Them][ROOK];
if (b)
- attackUnits += RookCheckBonus * count_1s(b);
+ attackUnits += RookCheck * popcount(b);
// Enemy bishops safe checks
b = b2 & ei.attackedBy[Them][BISHOP];
if (b)
- attackUnits += BishopCheckBonus * count_1s(b);
+ attackUnits += BishopCheck * popcount(b);
// Enemy knights safe checks
b = pos.attacks_from(ksq) & ei.attackedBy[Them][KNIGHT] & safe;
if (b)
- attackUnits += KnightCheckBonus * count_1s(b);
-
- // To index KingDangerTable[] attackUnits must be in [0, 99] range
- attackUnits = Min(99, Max(0, attackUnits));
-
- // Finally, extract the king danger score from the KingDangerTable[]
- // array and subtract the score from evaluation. Set also 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][attackUnits];
- margins[Us] += mg_value(KingDangerTable[Us][attackUnits]);
+ attackUnits += KnightCheck * popcount(b);
+
+ // To index KingDanger[] attackUnits must be in [0, 99] range
+ attackUnits = std::min(99, std::max(0, attackUnits));
+
+ // Finally, extract the king danger score from the KingDanger[]
+ // array and subtract the score from evaluation.
+ score -= KingDanger[attackUnits];
}
if (Trace)
- TracedScores[Us][KING] = score;
+ Tracing::write(KING, Us, score);
return score;
}
- // evaluate_passed_pawns<>() evaluates the passed pawns of the given color
+ // max_piece_type() is a helper function used by evaluate_threats() to get
+ // the value of the biggest PieceType of color C in 'target' bitboard.
- template
- Score evaluate_passed_pawns(const Position& pos, EvalInfo& ei) {
+ template
+ inline PieceType max_piece_type(const Position& pos, const Bitboard target) {
- const Color Them = (Us == WHITE ? BLACK : WHITE);
+ assert(target & (pos.pieces(C) ^ pos.pieces(C, KING)));
- Bitboard b, squaresToQueen, defendedSquares, unsafeSquares, supportingPawns;
- Score score = SCORE_ZERO;
+ for (PieceType pt = QUEEN; pt > PAWN; --pt)
+ if (target & pos.pieces(C, pt))
+ return pt;
- b = ei.pi->passed_pawns(Us);
-
- if (!b)
- return SCORE_ZERO;
-
- do {
- Square s = pop_1st_bit(&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(Us), blockSq) * 3 * rr);
- ebonus -= Value(square_distance(pos.king_square(Us), blockSq + pawn_push(Us)) * rr);
- ebonus += Value(square_distance(pos.king_square(Them), blockSq) * 6 * rr);
+ return PAWN;
+ }
- // If the pawn is free to advance, increase bonus
- if (pos.square_is_empty(blockSq))
- {
- squaresToQueen = squares_in_front_of(Us, s);
- defendedSquares = squaresToQueen & ei.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 ( (squares_in_front_of(Them, s) & pos.pieces(ROOK, QUEEN, Them))
- && (squares_in_front_of(Them, s) & pos.pieces(ROOK, QUEEN, Them) & pos.attacks_from(s)))
- unsafeSquares = squaresToQueen;
- else
- unsafeSquares = squaresToQueen & (ei.attackedBy[Them][0] | pos.pieces_of_color(Them));
-
- // If there aren't enemy attacks or pieces along the path to queen give
- // huge bonus. Even bigger if we protect the pawn's path.
- if (!unsafeSquares)
- ebonus += Value(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));
-
- // At last, add a small bonus when there are no *friendly* pieces
- // in the pawn's path.
- if (!(squaresToQueen & pos.pieces_of_color(Us)))
- ebonus += Value(rr);
- }
- } // 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(PAWN, Us) & neighboring_files_bb(s);
- if (supportingPawns & rank_bb(s))
- ebonus += Value(r * 20);
- else if (supportingPawns & rank_bb(s - pawn_push(Us)))
- ebonus += Value(r * 12);
-
- // Rook pawns are a special case: They are sometimes worse, and
- // sometimes better than other passed pawns. It is difficult to find
- // good rules for determining whether they are good or bad. For now,
- // we try the following: Increase the value for rook pawns if the
- // other side has no pieces apart from a knight, and decrease the
- // value if the other side has a rook or queen.
- if (square_file(s) == FILE_A || square_file(s) == FILE_H)
- {
- if (pos.non_pawn_material(Them) <= KnightValueMidgame)
- ebonus += ebonus / 4;
- else if (pos.pieces(ROOK, QUEEN, Them))
- ebonus -= ebonus / 4;
- }
- score += make_score(mbonus, ebonus);
+ // evaluate_threats() assigns bonuses according to the type of attacking piece
+ // and the type of attacked one.
- } while (b);
+ template
+ Score evaluate_threats(const Position& pos, const EvalInfo& ei) {
- // Add the scores to the middle game and endgame eval
- return apply_weight(score, Weights[PassedPawns]);
- }
+ const Color Them = (Us == WHITE ? BLACK : WHITE);
+ enum { Minor, Major };
- // 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.
+ Bitboard b, weakEnemies, protectedEnemies;
+ Score score = SCORE_ZERO;
- template
- Score evaluate_unstoppable_pawns(const Position& pos, EvalInfo& ei) {
+ // Enemies defended by a pawn and under our attack by a minor piece
+ protectedEnemies = (pos.pieces(Them) ^ pos.pieces(Them, PAWN))
+ & ei.attackedBy[Them][PAWN]
+ & (ei.attackedBy[Us][KNIGHT] | ei.attackedBy[Us][BISHOP]);
- const BitCountType Max15 = HasPopCnt ? CNT_POPCNT : CpuIs64Bit ? CNT64_MAX15 : CNT32_MAX15;
+ if (protectedEnemies)
+ score += Threat[Minor][max_piece_type(pos, protectedEnemies)];
- 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 };
+ // Enemies not defended by a pawn and under our attack
+ weakEnemies = pos.pieces(Them)
+ & ~ei.attackedBy[Them][PAWN]
+ & ei.attackedBy[Us][ALL_PIECES];
- // 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++)
+ // Add a bonus according if the attacking pieces are minor or major
+ if (weakEnemies)
{
- // Skip if other side has non-pawn pieces
- if (pos.non_pawn_material(opposite_color(c)))
- continue;
+ b = weakEnemies & (ei.attackedBy[Us][KNIGHT] | ei.attackedBy[Us][BISHOP]);
+ if (b)
+ score += Threat[Minor][max_piece_type(pos, b)];
- b = ei.pi->passed_pawns(c);
+ b = weakEnemies & (ei.attackedBy[Us][ROOK] | ei.attackedBy[Us][QUEEN]);
+ if (b)
+ score += Threat[Major][max_piece_type(pos, b)];
- while (b)
- {
- s = pop_1st_bit(&b);
- queeningSquare = relative_square(c, make_square(square_file(s), RANK_8));
- queeningPath = squares_in_front_of(c, s);
+ b = weakEnemies & ~ei.attackedBy[Them][ALL_PIECES];
+ if (b)
+ score += more_than_one(b) ? Hanging * popcount(b) : Hanging;
- // 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(opposite_color(c)), queeningSquare) - int(c != pos.side_to_move());
- pathDefended = ((ei.attackedBy[c][0] & queeningPath) == queeningPath);
+ b = weakEnemies & ei.attackedBy[Us][KING];
+ if (b)
+ score += more_than_one(b) ? KingOnMany : KingOnOne;
+ }
- if (movesToGo >= oppMovesToGo && !pathDefended)
- continue;
+ if (Trace)
+ Tracing::write(Tracing::THREAT, Us, score);
- // 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.occupied_squares() == queeningPath & pos.pieces_of_color(c));
+ return score;
+ }
- // Add moves needed to free the path from friendly pieces and retest condition
- movesToGo += count_1s(queeningPath & pos.pieces_of_color(c));
- if (movesToGo >= oppMovesToGo && !pathDefended)
- continue;
+ // evaluate_passed_pawns() evaluates the passed pawns of the given color
- pliesToGo = 2 * movesToGo - int(c == pos.side_to_move());
- pliesToQueen[c] = Min(pliesToQueen[c], pliesToGo);
- }
- }
+ template
+ Score evaluate_passed_pawns(const Position& pos, const EvalInfo& ei) {
- // 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;
+ const Color Them = (Us == WHITE ? BLACK : WHITE);
- winnerSide = (pliesToQueen[WHITE] < pliesToQueen[BLACK] ? WHITE : BLACK);
- loserSide = opposite_color(winnerSide);
+ Bitboard b, squaresToQueen, defendedSquares, unsafeSquares;
+ Score score = SCORE_ZERO;
- // Step 3. Can the losing side possibly create a new passed pawn and thus prevent the loss?
- b = candidates = pos.pieces(PAWN, loserSide);
+ b = ei.pi->passed_pawns(Us);
while (b)
{
- s = pop_1st_bit(&b);
+ Square s = pop_lsb(&b);
- // Compute plies from queening
- queeningSquare = relative_square(loserSide, make_square(square_file(s), RANK_8));
- movesToGo = rank_distance(s, queeningSquare) - int(relative_rank(loserSide, s) == RANK_2);
- pliesToGo = 2 * movesToGo - int(loserSide == pos.side_to_move());
+ assert(pos.pawn_passed(Us, s));
- // Check if (without even considering any obstacles) we're too far away or doubled
- if ( pliesToQueen[winnerSide] + 3 <= pliesToGo
- || (squares_in_front_of(loserSide, s) & pos.pieces(PAWN, loserSide)))
- clear_bit(&candidates, s);
- }
+ int r = relative_rank(Us, s) - RANK_2;
+ int rr = r * (r - 1);
- // 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;
+ // Base bonus based on rank
+ Value mbonus = Value(17 * rr), ebonus = Value(7 * (rr + r + 1));
- // Step 4. Check new passed pawn creation through king capturing and pawn sacrifices
- b = candidates;
+ if (rr)
+ {
+ Square blockSq = s + pawn_push(Us);
- while (b)
- {
- s = pop_1st_bit(&b);
- sacptg = blockersCount = 0;
- minKingDist = kingptg = 256;
+ // Adjust bonus based on the king's proximity
+ ebonus += square_distance(pos.king_square(Them), blockSq) * 5 * rr
+ - square_distance(pos.king_square(Us ), blockSq) * 2 * rr;
- // Compute plies from queening
- queeningSquare = relative_square(loserSide, make_square(square_file(s), RANK_8));
- movesToGo = rank_distance(s, queeningSquare) - int(relative_rank(loserSide, s) == RANK_2);
- pliesToGo = 2 * movesToGo - int(loserSide == pos.side_to_move());
+ // If blockSq is not the queening square then consider also a second push
+ if (relative_rank(Us, blockSq) != RANK_8)
+ ebonus -= square_distance(pos.king_square(Us), blockSq + pawn_push(Us)) * rr;
- // Generate list of blocking pawns and supporters
- supporters = neighboring_files_bb(s) & candidates;
- opposed = squares_in_front_of(loserSide, s) & pos.pieces(PAWN, winnerSide);
- blockers = passed_pawn_mask(loserSide, s) & pos.pieces(PAWN, winnerSide);
+ // If the pawn is free to advance, then increase the bonus
+ if (pos.empty(blockSq))
+ {
+ // If there is a rook or queen attacking/defending the pawn from behind,
+ // consider all the squaresToQueen. Otherwise consider only the squares
+ // in the pawn's path attacked or occupied by the enemy.
+ defendedSquares = unsafeSquares = squaresToQueen = forward_bb(Us, s);
- assert(blockers);
+ Bitboard bb = forward_bb(Them, s) & pos.pieces(ROOK, QUEEN) & pos.attacks_from(s);
- // How many plies does it take to remove all the blocking pawns?
- while (blockers)
- {
- blockSq = pop_1st_bit(&blockers);
- movesToGo = 256;
+ if (!(pos.pieces(Us) & bb))
+ defendedSquares &= ei.attackedBy[Us][ALL_PIECES];
- // 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));
+ if (!(pos.pieces(Them) & bb))
+ unsafeSquares &= ei.attackedBy[Them][ALL_PIECES] | pos.pieces(Them);
- while (b2) // This while-loop could be replaced with LSB/MSB (depending on color)
- {
- d = square_distance(blockSq, pop_1st_bit(&b2)) - 2;
- movesToGo = Min(movesToGo, d);
- }
- }
+ // If there aren't any enemy attacks, assign a big bonus. Otherwise
+ // assign a smaller bonus if the block square isn't attacked.
+ int k = !unsafeSquares ? 15 : !(unsafeSquares & blockSq) ? 9 : 0;
- // Check pawns that can be sacrificed against the blocking pawn
- b2 = attack_span_mask(winnerSide, blockSq) & candidates & ~(1ULL << s);
+ // If the path to queen is fully defended, assign a big bonus.
+ // Otherwise assign a smaller bonus if the block square is defended.
+ if (defendedSquares == squaresToQueen)
+ k += 6;
- while (b2) // This while-loop could be replaced with LSB/MSB (depending on color)
- {
- d = square_distance(blockSq, pop_1st_bit(&b2)) - 2;
- movesToGo = Min(movesToGo, d);
+ else if (defendedSquares & blockSq)
+ k += 4;
+
+ mbonus += k * rr, ebonus += k * rr;
}
+ else if (pos.pieces(Us) & blockSq)
+ mbonus += rr * 3 + r * 2 + 3, ebonus += rr + r * 2;
+ } // rr != 0
- // If 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;
+ if (pos.count(Us) < pos.count(Them))
+ ebonus += ebonus / 4;
- // Plies needed to sacrifice against all the blocking pawns
- sacptg += movesToGo * 2;
- blockersCount++;
+ score += make_score(mbonus, ebonus);
+ }
- // Plies needed for the king to capture all the blocking pawns
- d = square_distance(pos.king_square(loserSide), blockSq);
- minKingDist = Min(minKingDist, d);
- kingptg = (minKingDist + blockersCount) * 2;
- }
+ if (Trace)
+ Tracing::write(Tracing::PASSED, Us, apply_weight(score, Weights[PassedPawns]));
- // Check if pawn sacrifice plan _may_ save the day
- if (pliesToQueen[winnerSide] + 3 > pliesToGo + sacptg)
- return SCORE_ZERO;
+ // Add the scores to the middlegame and endgame eval
+ return apply_weight(score, Weights[PassedPawns]);
+ }
- // 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) 0x500 - 0x20 * pliesToQueen[winnerSide]);
- return winnerSide == WHITE ? score : -score;
+ // evaluate_unstoppable_pawns() scores the most advanced passed pawn. In case
+ // both players have no pieces but pawns, this is somewhat related to the
+ // possibility that pawns are unstoppable.
+
+ Score evaluate_unstoppable_pawns(Color us, const EvalInfo& ei) {
+
+ Bitboard b = ei.pi->passed_pawns(us);
+
+ return b ? Unstoppable * int(relative_rank(us, frontmost_sq(us, b))) : SCORE_ZERO;
}
@@ -1050,170 +661,259 @@ namespace {
// squares one, two or three squares behind a friendly pawn are counted
// twice. Finally, the space bonus is scaled by a weight taken from the
// material hash table. The aim is to improve play on game opening.
- template
- int evaluate_space(const Position& pos, EvalInfo& ei) {
+ template
+ int evaluate_space(const Position& pos, const EvalInfo& ei) {
- const BitCountType Max15 = HasPopCnt ? CNT_POPCNT : CpuIs64Bit ? CNT64_MAX15 : CNT32_MAX15;
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(PAWN, Us)
+ & ~pos.pieces(Us, PAWN)
& ~ei.attackedBy[Them][PAWN]
- & (ei.attackedBy[Us][0] | ~ei.attackedBy[Them][0]);
+ & (ei.attackedBy[Us][ALL_PIECES] | ~ei.attackedBy[Them][ALL_PIECES]);
// Find all squares which are at most three squares behind some friendly pawn
- Bitboard behind = pos.pieces(PAWN, Us);
+ Bitboard behind = pos.pieces(Us, PAWN);
behind |= (Us == WHITE ? behind >> 8 : behind << 8);
behind |= (Us == WHITE ? behind >> 16 : behind << 16);
- return count_1s(safe) + count_1s(behind & safe);
+ // Since SpaceMask[Us] is fully on our half of the board
+ assert(unsigned(safe >> (Us == WHITE ? 32 : 0)) == 0);
+
+ // Count safe + (behind & safe) with a single popcount
+ return popcount((Us == WHITE ? safe << 32 : safe >> 32) | (behind & safe));
}
- // apply_weight() applies an evaluation weight to a value trying to prevent overflow
+ // do_evaluate() is the evaluation entry point, called directly from evaluate()
- 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);
- }
+ template
+ Value do_evaluate(const Position& pos) {
+ assert(!pos.checkers());
- // 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.
+ EvalInfo ei;
+ Score score, mobility[2] = { SCORE_ZERO, SCORE_ZERO };
+ Thread* thisThread = pos.this_thread();
- Value scale_by_game_phase(const Score& v, Phase ph, ScaleFactor sf) {
+ // Initialize score by reading the incrementally updated scores included
+ // in the position object (material + piece square tables).
+ // Score is computed from the point of view of white.
+ score = pos.psq_score();
- 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);
+ // Probe the material hash table
+ ei.mi = Material::probe(pos, thisThread->materialTable, thisThread->endgames);
+ score += ei.mi->material_value();
- 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));
- }
+ // 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) + Eval::Tempo;
+ // Probe the pawn hash table
+ ei.pi = Pawns::probe(pos, thisThread->pawnsTable);
+ score += apply_weight(ei.pi->pawns_value(), Weights[PawnStructure]);
- // weight_option() computes the value of an evaluation weight, by combining
- // two UCI-configurable weights (midgame and endgame) with an internal weight.
+ // Initialize attack and king safety bitboards
+ init_eval_info(pos, ei);
+ init_eval_info(pos, ei);
- Score weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight) {
+ ei.attackedBy[WHITE][ALL_PIECES] |= ei.attackedBy[WHITE][KING];
+ ei.attackedBy[BLACK][ALL_PIECES] |= ei.attackedBy[BLACK][KING];
- // Scale option value from 100 to 256
- int mg = Options[mgOpt].value() * 256 / 100;
- int eg = Options[egOpt].value() * 256 / 100;
+ // Do not include in mobility squares protected by enemy pawns or occupied by our pawns or king
+ Bitboard mobilityArea[] = { ~(ei.attackedBy[BLACK][PAWN] | pos.pieces(WHITE, PAWN, KING)),
+ ~(ei.attackedBy[WHITE][PAWN] | pos.pieces(BLACK, PAWN, KING)) };
- return apply_weight(make_score(mg, eg), internalWeight);
- }
+ // Evaluate pieces and mobility
+ score += evaluate_pieces(pos, ei, mobility, mobilityArea);
+ score += apply_weight(mobility[WHITE] - mobility[BLACK], Weights[Mobility]);
+ // Evaluate kings after all other pieces because we need complete attack
+ // information when computing the king safety evaluation.
+ score += evaluate_king(pos, ei)
+ - evaluate_king(pos, ei);
- // init_safety() initizes the king safety evaluation, based on UCI
- // parameters. It is called from read_weights().
+ // Evaluate tactical threats, we need full attack information including king
+ score += evaluate_threats(pos, ei)
+ - evaluate_threats(pos, ei);
- void init_safety() {
+ // Evaluate passed pawns, we need full attack information including king
+ score += evaluate_passed_pawns(pos, ei)
+ - evaluate_passed_pawns(pos, ei);
- const Value MaxSlope = Value(30);
- const Value Peak = Value(1280);
- Value t[100];
+ // If both sides have only pawns, score for potential unstoppable pawns
+ if (!pos.non_pawn_material(WHITE) && !pos.non_pawn_material(BLACK))
+ score += evaluate_unstoppable_pawns(WHITE, ei)
+ - evaluate_unstoppable_pawns(BLACK, ei);
- // First setup the base table
- for (int i = 0; i < 100; i++)
+ // Evaluate space for both sides, only in middlegame
+ if (ei.mi->space_weight())
{
- t[i] = Value(int(0.4 * i * i));
+ int s = evaluate_space(pos, ei) - evaluate_space(pos, ei);
+ score += apply_weight(s * ei.mi->space_weight(), Weights[Space]);
+ }
- if (i > 0)
- t[i] = Min(t[i], t[i - 1] + MaxSlope);
+ // Scale winning side if position is more drawish than it appears
+ Color strongSide = eg_value(score) > VALUE_DRAW ? WHITE : BLACK;
+ ScaleFactor sf = ei.mi->scale_factor(pos, strongSide);
- t[i] = Min(t[i], Peak);
+ // If we don't already have an unusual scale factor, check for certain
+ // types of endgames, and use a lower scale for those.
+ if ( ei.mi->game_phase() < PHASE_MIDGAME
+ && (sf == SCALE_FACTOR_NORMAL || sf == SCALE_FACTOR_ONEPAWN))
+ {
+ if (pos.opposite_bishops())
+ {
+ // Endgame with opposite-colored bishops and no other pieces (ignoring pawns)
+ // is almost a draw, in case of KBP vs KB is even more a draw.
+ if ( pos.non_pawn_material(WHITE) == BishopValueMg
+ && pos.non_pawn_material(BLACK) == BishopValueMg)
+ sf = more_than_one(pos.pieces(PAWN)) ? ScaleFactor(32) : ScaleFactor(8);
+
+ // Endgame with opposite-colored bishops, but also other pieces. Still
+ // a bit drawish, but not as drawish as with only the two bishops.
+ else
+ sf = ScaleFactor(50 * sf / SCALE_FACTOR_NORMAL);
+ }
+ // Endings where weaker side can place his king in front of the opponent's
+ // pawns are drawish.
+ else if ( abs(eg_value(score)) <= BishopValueEg
+ && ei.pi->pawn_span(strongSide) <= 1
+ && !pos.pawn_passed(~strongSide, pos.king_square(~strongSide)))
+ sf = ScaleFactor(ScalePawnSpan[ei.pi->pawn_span(strongSide)]);
}
- // 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]);
+ // Interpolate between a middlegame and a (scaled by 'sf') endgame score
+ Value v = mg_value(score) * int(ei.mi->game_phase())
+ + eg_value(score) * int(PHASE_MIDGAME - ei.mi->game_phase()) * sf / SCALE_FACTOR_NORMAL;
+
+ v /= int(PHASE_MIDGAME);
+
+ // In case of tracing add all single evaluation contributions for both white and black
+ if (Trace)
+ {
+ Tracing::write(Tracing::MATERIAL, pos.psq_score());
+ Tracing::write(Tracing::IMBALANCE, ei.mi->material_value());
+ Tracing::write(PAWN, ei.pi->pawns_value());
+ Tracing::write(Tracing::MOBILITY, apply_weight(mobility[WHITE], Weights[Mobility])
+ , apply_weight(mobility[BLACK], Weights[Mobility]));
+ Score w = ei.mi->space_weight() * evaluate_space(pos, ei);
+ Score b = ei.mi->space_weight() * evaluate_space(pos, ei);
+ Tracing::write(Tracing::SPACE, apply_weight(w, Weights[Space]), apply_weight(b, Weights[Space]));
+ Tracing::write(Tracing::TOTAL, score);
+ Tracing::ei = ei;
+ Tracing::sf = sf;
+ }
+
+ return (pos.side_to_move() == WHITE ? v : -v) + Eval::Tempo;
}
- // 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.
+ // Tracing function definitions
- double to_cp(Value v) { return double(v) / double(PawnValueMidgame); }
+ double Tracing::to_cp(Value v) { return double(v) / PawnValueEg; }
- void trace_add(int idx, Score wScore, Score bScore) {
+ void Tracing::write(int idx, Color c, Score s) { scores[c][idx] = s; }
- TracedScores[WHITE][idx] = wScore;
- TracedScores[BLACK][idx] = bScore;
- }
+ void Tracing::write(int idx, Score w, Score b) {
- // trace_row() is an helper function used by tracing code to register the
- // values of a single evaluation term.
+ write(idx, WHITE, w);
+ write(idx, BLACK, b);
+ }
- void trace_row(const char *name, int idx) {
+ void Tracing::print(std::stringstream& ss, const char* name, int idx) {
- Score wScore = TracedScores[WHITE][idx];
- Score bScore = TracedScores[BLACK][idx];
+ Score wScore = scores[WHITE][idx];
+ Score bScore = scores[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";
+ case MATERIAL: case IMBALANCE: case PAWN: case TOTAL:
+ ss << std::setw(15) << name << " | --- --- | --- --- | "
+ << std::setw(5) << to_cp(mg_value(wScore - bScore)) << " "
+ << std::setw(5) << to_cp(eg_value(wScore - bScore)) << " \n";
break;
default:
- 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";
+ ss << std::setw(15) << name << " | " << std::noshowpos
+ << std::setw(5) << to_cp(mg_value(wScore)) << " "
+ << std::setw(5) << to_cp(eg_value(wScore)) << " | "
+ << std::setw(5) << to_cp(mg_value(bScore)) << " "
+ << std::setw(5) << to_cp(eg_value(bScore)) << " | "
+ << std::setw(5) << to_cp(mg_value(wScore - bScore)) << " "
+ << std::setw(5) << to_cp(eg_value(wScore - bScore)) << " \n";
}
}
-}
+ std::string Tracing::do_trace(const Position& pos) {
-/// trace_evaluate() 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.
+ std::memset(scores, 0, sizeof(scores));
-std::string trace_evaluate(const Position& pos) {
+ Value v = do_evaluate(pos);
+ v = pos.side_to_move() == WHITE ? v : -v; // White's point of view
- Value margin;
- std::string totals;
+ 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";
- TraceStream.str("");
- TraceStream << std::showpoint << std::showpos << std::fixed << std::setprecision(2);
- memset(TracedScores, 0, 2 * 16 * sizeof(Score));
+ print(ss, "Material", MATERIAL);
+ print(ss, "Imbalance", IMBALANCE);
+ print(ss, "Pawns", PAWN);
+ print(ss, "Knights", KNIGHT);
+ print(ss, "Bishops", BISHOP);
+ print(ss, "Rooks", ROOK);
+ print(ss, "Queens", QUEEN);
+ print(ss, "Mobility", MOBILITY);
+ print(ss, "King safety", KING);
+ print(ss, "Threats", THREAT);
+ print(ss, "Passed pawns", PASSED);
+ print(ss, "Space", SPACE);
- do_evaluate(pos, margin);
+ ss << "----------------+-------------+-------------+-------------\n";
+ print(ss, "Total", TOTAL);
- totals = TraceStream.str();
- TraceStream.str("");
+ ss << "\nTotal Evaluation: " << to_cp(v) << " (white side)\n";
- TraceStream << std::setw(21) << "Eval term " << "| White | Black | Total \n"
- << " | MG EG | MG EG | MG EG \n"
- << "---------------------+-------------+-------------+---------------\n";
+ return ss.str();
+ }
+
+} // namespace
- 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;
+namespace Eval {
+
+ /// evaluate() is the main evaluation function. It returns a static evaluation
+ /// of the position always from the point of view of the side to move.
+
+ Value evaluate(const Position& pos) {
+ return do_evaluate(pos);
+ }
+
+
+ /// 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);
+ }
+
+
+ /// init() computes evaluation weights.
+
+ void init() {
+
+ const double MaxSlope = 30;
+ const double Peak = 1280;
+
+ for (int t = 0, i = 1; i < 100; ++i)
+ {
+ t = int(std::min(Peak, std::min(0.4 * i * i, t + MaxSlope)));
+ KingDanger[i] = apply_weight(make_score(t, 0), Weights[KingSafety]);
+ }
+ }
- return TraceStream.str();
-}
+} // namespace Eval