/*
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) 2008-2013 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 <iomanip>
+#include <sstream>
+#include <algorithm>
#include "bitcount.h"
#include "evaluate.h"
#include "thread.h"
#include "ucioption.h"
+namespace {
-////
-//// Local definitions
-////
+ enum ExtendedPieceType { // Used for tracing
+ PST = 8, IMBALANCE, MOBILITY, THREAT, PASSED, SPACE, TOTAL
+ };
-namespace {
+ namespace Tracing {
+
+ Score scores[COLOR_NB][TOTAL + 1];
+ std::stringstream stream;
+
+ void add(int idx, Score term_w, Score term_b = SCORE_ZERO);
+ void row(const char* name, int idx);
+ std::string do_trace(const Position& pos);
+ }
// Struct EvalInfo contains various information computed and collected
// by the evaluation functions.
struct EvalInfo {
- // Pointer to pawn hash table entry
- PawnInfo* pi;
-
- // updateKingTables[color] is set to true if we have enough material
- // to trigger the opponent's king safety calculation. When is false we
- // skip the time consuming update of the king attackers tables.
- bool updateKingTables[2];
+ // 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][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];
};
// Evaluation grain size, must be a power of 2
- const int GrainSize = 8;
+ const int GrainSize = 4;
// Evaluation weights, initialized from UCI options
enum { Mobility, PawnStructure, PassedPawns, Space, KingDangerUs, KingDangerThem };
//
// 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)
};
- // 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.
+ // 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(-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) }
};
- // 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] = {
+ // Outpost[PieceType][Square] contains bonuses of knights and bishops, 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(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),
- V(0), V(0), V(0), V(0), V(0), V(0), V(0), 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),
- V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0),
- V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0) }
+ 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] = {
+ // 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( 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( 0, 22), S(15, 49), S(15, 49), S( 0, 0), S(24, 49) }, // ROOK
{ S(0, 0), S(15, 39), S(15, 39), S(15, 39), S(15, 39), S( 0, 0) } // QUEEN
};
- // ThreatedByPawnPenalty[PieceType] contains a penalty according to which
- // piece type is attacked by an enemy pawn.
- const Score ThreatedByPawnPenalty[] = {
+ // 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)
};
#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);
+ const Score Tempo = make_score(24, 11);
+ const Score BishopPin = make_score(66, 11);
+ const Score RookOn7th = make_score(11, 20);
+ const Score QueenOn7th = make_score( 3, 8);
+ const Score RookOnPawn = make_score(10, 28);
+ const Score QueenOnPawn = make_score( 4, 20);
+ const Score RookOpenFile = make_score(43, 21);
+ const Score RookSemiopenFile = make_score(19, 10);
+ const Score BishopPawns = make_score( 8, 12);
+ 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);
+
+ // 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);
// The SpaceMask[Color] contains the area of the board which is considered
// by the space evaluation. In the middle game, each side is given a bonus
// based on how many squares inside this area are safe and available for
// friendly minor pieces.
const Bitboard SpaceMask[] = {
- (1ULL << SQ_C2) | (1ULL << SQ_D2) | (1ULL << SQ_E2) | (1ULL << SQ_F2) |
- (1ULL << SQ_C3) | (1ULL << SQ_D3) | (1ULL << SQ_E3) | (1ULL << SQ_F3) |
- (1ULL << SQ_C4) | (1ULL << SQ_D4) | (1ULL << SQ_E4) | (1ULL << SQ_F4),
- (1ULL << SQ_C7) | (1ULL << SQ_D7) | (1ULL << SQ_E7) | (1ULL << SQ_F7) |
- (1ULL << SQ_C6) | (1ULL << SQ_D6) | (1ULL << SQ_E6) | (1ULL << SQ_F6) |
- (1ULL << SQ_C5) | (1ULL << SQ_D5) | (1ULL << SQ_E5) | (1ULL << SQ_F5)
+ (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
+ // from the 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 KingDangerTable[].
+ // 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
+ const int QueenContactCheck = 6;
+ const int RookContactCheck = 4;
+ const int QueenCheck = 3;
+ const int RookCheck = 2;
+ const int BishopCheck = 1;
+ const int KnightCheck = 1;
+
+ // KingExposed[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[] = {
+ const int KingExposed[] = {
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
};
- // KingDangerTable[Color][attackUnits] contains the actual king danger
- // weighted scores, indexed by color and by a calculated integer number.
- Score KingDangerTable[2][128];
-
- // 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];
+ // KingDanger[Color][attackUnits] contains the actual king danger weighted
+ // scores, indexed by color and by a calculated integer number.
+ Score KingDanger[COLOR_NB][128];
// Function prototypes
- template<bool HasPopCnt>
- Value do_evaluate(const Position& pos, Value margins[]);
+ template<bool Trace>
+ Value do_evaluate(const Position& pos, Value& margin);
- template<Color Us, bool HasPopCnt>
+ template<Color Us>
void init_eval_info(const Position& pos, EvalInfo& ei);
- template<Color Us, bool HasPopCnt>
+ template<Color Us, bool Trace>
Score evaluate_pieces_of_color(const Position& pos, EvalInfo& ei, Score& mobility);
- template<Color Us, bool HasPopCnt>
- Score evaluate_king(const Position& pos, EvalInfo& ei, Value margins[]);
+ template<Color Us, bool Trace>
+ Score evaluate_king(const Position& pos, const EvalInfo& ei, Value margins[]);
- template<Color Us>
- Score evaluate_threats(const Position& pos, EvalInfo& ei);
+ template<Color Us, bool Trace>
+ Score evaluate_threats(const Position& pos, const EvalInfo& ei);
- template<Color Us, bool HasPopCnt>
- int evaluate_space(const Position& pos, EvalInfo& ei);
+ template<Color Us, bool Trace>
+ Score evaluate_passed_pawns(const Position& pos, const EvalInfo& ei);
template<Color Us>
- Score evaluate_passed_pawns(const Position& pos, EvalInfo& ei);
+ int evaluate_space(const Position& pos, const EvalInfo& ei);
+
+ Score evaluate_unstoppable_pawns(const Position& pos, Color us, const EvalInfo& ei);
- Score apply_weight(Score v, Score weight);
- Value scale_by_game_phase(const Score& v, Phase ph, const ScaleFactor sf[]);
+ Value interpolate(const Score& v, Phase ph, ScaleFactor sf);
+ Score apply_weight(Score v, Score w);
Score weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight);
- void init_safety();
+ double to_cp(Value v);
}
-////
-//// Functions
-////
+namespace Eval {
+ /// evaluate() is the main evaluation function. It always computes two
+ /// values, an endgame score and a middle game score, and interpolates
+ /// between them based on the remaining material.
-/// Prefetches in pawn hash tables
+ Value evaluate(const Position& pos, Value& margin) {
+ return do_evaluate<false>(pos, margin);
+ }
-void prefetchPawn(Key key, int threadID) {
- PawnTable[threadID]->prefetch(key);
-}
+ /// trace() is like evaluate() but instead of a value returns a string suitable
+ /// to be print on stdout with the detailed descriptions and values of each
+ /// evaluation term. Used mainly for debugging.
+ std::string trace(const Position& pos) {
+ return Tracing::do_trace(pos);
+ }
-/// 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 margins[]) {
+ /// init() computes evaluation weights from the corresponding UCI parameters
+ /// and setup king tables.
- return CpuHasPOPCNT ? do_evaluate<true>(pos, margins)
- : do_evaluate<false>(pos, margins);
-}
+ void init() {
-namespace {
+ 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]);
-template<bool HasPopCnt>
-Value do_evaluate(const Position& pos, Value margins[]) {
+ const int MaxSlope = 30;
+ const int Peak = 1280;
- EvalInfo ei;
- ScaleFactor factor[2];
- Score mobilityWhite, mobilityBlack;
+ for (int t = 0, i = 1; i < 100; ++i)
+ {
+ t = std::min(Peak, std::min(int(0.4 * i * i), t + MaxSlope));
+
+ KingDanger[1][i] = apply_weight(make_score(t, 0), Weights[KingDangerUs]);
+ KingDanger[0][i] = apply_weight(make_score(t, 0), Weights[KingDangerThem]);
+ }
+ }
+
+} // namespace Eval
- assert(pos.is_ok());
- assert(pos.thread() >= 0 && pos.thread() < MAX_THREADS);
- assert(!pos.is_check());
- // Initialize value by reading the incrementally updated scores included
- // in the position object (material + piece square tables).
- Score bonus = pos.value();
+namespace {
+
+template<bool Trace>
+Value do_evaluate(const Position& pos, Value& margin) {
+
+ assert(!pos.checkers());
+
+ EvalInfo ei;
+ Value margins[COLOR_NB];
+ Score score, mobilityWhite, mobilityBlack;
+ Thread* th = pos.this_thread();
- // margins[color] is the uncertainty estimation of position's evaluation
- // and typically is used by the search for pruning decisions.
+ // margins[] store the uncertainty estimation of position's evaluation
+ // that typically is used by the search for pruning decisions.
margins[WHITE] = margins[BLACK] = VALUE_ZERO;
+ // Initialize score by reading the incrementally updated scores included
+ // in the position object (material + piece square tables) and adding
+ // Tempo bonus. Score is computed from the point of view of white.
+ score = pos.psq_score() + (pos.side_to_move() == WHITE ? Tempo : -Tempo);
+
// Probe the material hash table
- MaterialInfo* mi = MaterialTable[pos.thread()]->get_material_info(pos);
- bonus += mi->material_value();
+ ei.mi = Material::probe(pos, th->materialTable, th->endgames);
+ score += ei.mi->material_value();
// If we have a specialized evaluation function for the current material
// configuration, call it and return.
- if (mi->specialized_eval_exists())
- return mi->evaluate(pos);
-
- // After get_material_info() call that modifies them
- factor[WHITE] = mi->scale_factor(pos, WHITE);
- factor[BLACK] = mi->scale_factor(pos, BLACK);
+ if (ei.mi->specialized_eval_exists())
+ {
+ margin = VALUE_ZERO;
+ return ei.mi->evaluate(pos);
+ }
// Probe the pawn hash table
- ei.pi = PawnTable[pos.thread()]->get_pawn_info(pos);
- bonus += apply_weight(ei.pi->pawns_value(), Weights[PawnStructure]);
+ ei.pi = Pawns::probe(pos, th->pawnsTable);
+ score += apply_weight(ei.pi->pawns_value(), Weights[PawnStructure]);
// Initialize attack and king safety bitboards
- init_eval_info<WHITE, HasPopCnt>(pos, ei);
- init_eval_info<BLACK, HasPopCnt>(pos, ei);
+ init_eval_info<WHITE>(pos, ei);
+ init_eval_info<BLACK>(pos, ei);
// Evaluate pieces and mobility
- bonus += evaluate_pieces_of_color<WHITE, HasPopCnt>(pos, ei, mobilityWhite)
- - evaluate_pieces_of_color<BLACK, HasPopCnt>(pos, ei, mobilityBlack);
+ score += evaluate_pieces_of_color<WHITE, Trace>(pos, ei, mobilityWhite)
+ - evaluate_pieces_of_color<BLACK, Trace>(pos, ei, mobilityBlack);
- bonus += apply_weight(mobilityWhite - mobilityBlack, Weights[Mobility]);
+ 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.
- bonus += evaluate_king<WHITE, HasPopCnt>(pos, ei, margins)
- - evaluate_king<BLACK, HasPopCnt>(pos, ei, margins);
+ score += evaluate_king<WHITE, Trace>(pos, ei, margins)
+ - evaluate_king<BLACK, Trace>(pos, ei, margins);
// Evaluate tactical threats, we need full attack information including king
- bonus += evaluate_threats<WHITE>(pos, ei)
- - evaluate_threats<BLACK>(pos, ei);
+ score += evaluate_threats<WHITE, Trace>(pos, ei)
+ - evaluate_threats<BLACK, Trace>(pos, ei);
// Evaluate passed pawns, we need full attack information including king
- bonus += evaluate_passed_pawns<WHITE>(pos, ei)
- - evaluate_passed_pawns<BLACK>(pos, ei);
+ score += evaluate_passed_pawns<WHITE, Trace>(pos, ei)
+ - evaluate_passed_pawns<BLACK, Trace>(pos, ei);
- Phase phase = mi->game_phase();
+ // 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 middle-game.
- if (phase > PHASE_ENDGAME && mi->space_weight() > 0)
+ if (ei.mi->space_weight())
{
- int s = evaluate_space<WHITE, HasPopCnt>(pos, ei) - evaluate_space<BLACK, HasPopCnt>(pos, ei);
- bonus += apply_weight(make_score(s * mi->space_weight(), 0), Weights[Space]);
+ int s = evaluate_space<WHITE>(pos, ei) - evaluate_space<BLACK>(pos, ei);
+ score += apply_weight(s * ei.mi->space_weight(), Weights[Space]);
}
+ // 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 ( phase < PHASE_MIDGAME
- && pos.opposite_colored_bishops()
- && ( (factor[WHITE] == SCALE_FACTOR_NORMAL && eg_value(bonus) > VALUE_ZERO)
- || (factor[BLACK] == SCALE_FACTOR_NORMAL && eg_value(bonus) < VALUE_ZERO)))
+ // colored bishop endgames, and use a lower scale for those.
+ if ( ei.mi->game_phase() < PHASE_MIDGAME
+ && pos.opposite_bishops()
+ && sf == SCALE_FACTOR_NORMAL)
{
- ScaleFactor sf;
-
// Only the two bishops ?
- if ( pos.non_pawn_material(WHITE) == BishopValueMidgame
- && pos.non_pawn_material(BLACK) == BishopValueMidgame)
+ 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;
}
- // Interpolate between the middle game and the endgame score
- Value v = scale_by_game_phase(bonus, phase, factor);
- return pos.side_to_move() == WHITE ? v : -v;
-}
-
-} // namespace
-
-
-/// init_eval() initializes various tables used by the evaluation function
-
-void init_eval(int threads) {
+ margin = margins[pos.side_to_move()];
+ Value v = interpolate(score, ei.mi->game_phase(), sf);
- assert(threads <= MAX_THREADS);
-
- 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();
-
- if (!MaterialTable[i])
- MaterialTable[i] = new MaterialInfoTable();
+ Tracing::add(PST, pos.psq_score());
+ Tracing::add(IMBALANCE, ei.mi->material_value());
+ Tracing::add(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(SPACE, apply_weight(w, Weights[Space]), apply_weight(b, Weights[Space]));
+ Tracing::add(TOTAL, score);
+ Tracing::stream << "\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);
}
-}
-
-
-/// quit_eval() releases heap-allocated memory at program termination
-
-void quit_eval() {
-
- init_eval(0);
-}
-
-
-/// read_weights() reads evaluation weights from the corresponding UCI parameters
-
-void read_weights(Color us) {
-
- // King safety is asymmetrical. Our king danger level is weighted by
- // "Cowardice" UCI parameter, instead the opponent one by "Aggressiveness".
- const int kingDangerUs = (us == WHITE ? KingDangerUs : KingDangerThem);
- const int kingDangerThem = (us == WHITE ? KingDangerThem : KingDangerUs);
- Weights[Mobility] = weight_option("Mobility (Middle Game)", "Mobility (Endgame)", WeightsInternal[Mobility]);
- Weights[PawnStructure] = weight_option("Pawn Structure (Middle Game)", "Pawn Structure (Endgame)", WeightsInternal[PawnStructure]);
- Weights[PassedPawns] = weight_option("Passed Pawns (Middle Game)", "Passed Pawns (Endgame)", WeightsInternal[PassedPawns]);
- Weights[Space] = weight_option("Space", "Space", WeightsInternal[Space]);
- Weights[kingDangerUs] = weight_option("Cowardice", "Cowardice", WeightsInternal[KingDangerUs]);
- Weights[kingDangerThem] = weight_option("Aggressiveness", "Aggressiveness", WeightsInternal[KingDangerThem]);
-
- // If running in analysis mode, make sure we use symmetrical king safety. We do this
- // by replacing both Weights[kingDangerUs] and Weights[kingDangerThem] by their average.
- if (get_option_value_bool("UCI_AnalyseMode"))
- Weights[kingDangerUs] = Weights[kingDangerThem] = (Weights[kingDangerUs] + Weights[kingDangerThem]) / 2;
-
- init_safety();
+ return pos.side_to_move() == WHITE ? v : -v;
}
-namespace {
-
// init_eval_info() initializes king bitboards for given color adding
// pawn attacks. To be done at the beginning of the evaluation.
- template<Color Us, bool HasPopCnt>
+ template<Color Us>
void init_eval_info(const Position& pos, EvalInfo& ei) {
- const Color Them = (Us == WHITE ? BLACK : WHITE);
+ const Color Them = (Us == WHITE ? BLACK : WHITE);
+ const Square Down = (Us == WHITE ? DELTA_S : DELTA_N);
Bitboard b = ei.attackedBy[Them][KING] = pos.attacks_from<KING>(pos.king_square(Them));
- ei.kingZone[Us] = (b | (Us == WHITE ? b >> 8 : b << 8));
ei.attackedBy[Us][PAWN] = ei.pi->pawn_attacks(Us);
- ei.updateKingTables[Us] = pos.piece_count(Us, QUEEN) && pos.non_pawn_material(Us) >= QueenValueMidgame + RookValueMidgame;
- if (ei.updateKingTables[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 ? count_1s_max_15<HasPopCnt>(b) / 2 : EmptyBoardBB;
- ei.kingAdjacentZoneAttacksCount[Us] = ei.kingAttackersWeight[Us] = EmptyBoardBB;
- }
+ ei.kingAttackersCount[Us] = b ? popcount<Max15>(b) / 2 : 0;
+ ei.kingAdjacentZoneAttacksCount[Us] = ei.kingAttackersWeight[Us] = 0;
+ } else
+ ei.kingRing[Them] = ei.kingAttackersCount[Us] = 0;
}
assert (Piece == BISHOP || Piece == KNIGHT);
// Initial bonus based on square
- Value bonus = OutpostBonus[Piece == BISHOP][relative_square(Us, s)];
+ Value bonus = Outpost[Piece == BISHOP][relative_square(Us, s)];
// Increase bonus if supported by pawn, especially if the opponent has
// no minor piece which can exchange the outpost piece.
- if (bonus && bit_is_set(ei.attackedBy[Us][PAWN], s))
+ 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;
// evaluate_pieces<>() assigns bonuses and penalties to the pieces of a given color
- template<PieceType Piece, Color Us, bool HasPopCnt>
- Score evaluate_pieces(const Position& pos, EvalInfo& ei, Score& mobility, Bitboard no_mob_area) {
+ template<PieceType Piece, 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;
- Score bonus = SCORE_ZERO;
+ 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<Piece>(Us);
- ei.attackedBy[Us][Piece] = EmptyBoardBB;
+ ei.attackedBy[Us][Piece] = 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<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 = Piece == BISHOP ? attacks_bb<BISHOP>(s, pos.pieces() ^ pos.pieces(Us, QUEEN))
+ : Piece == ROOK ? attacks_bb< ROOK>(s, pos.pieces() ^ pos.pieces(Us, ROOK, QUEEN))
+ : pos.attacks_from<Piece>(s);
- // Update attack info
ei.attackedBy[Us][Piece] |= b;
- // King attacks
- if (ei.updateKingTables[Us] && (b & ei.kingZone[Us]))
+ if (b & ei.kingRing[Them])
{
- ei.kingAttackersCount[Us]++;
+ ++ei.kingAttackersCount[Us];
ei.kingAttackersWeight[Us] += KingAttackWeights[Piece];
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 = Piece != QUEEN ? popcount<Max15>(b & mobilityArea)
+ : popcount<Full >(b & mobilityArea);
mobility += MobilityBonus[Piece][mob];
// 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))
- bonus -= ThreatedByPawnPenalty[Piece];
+ if (ei.attackedBy[Them][PAWN] & s)
+ score -= ThreatenedByPawn[Piece];
+
+ // Otherwise give a bonus if we are a bishop and can pin a piece or can
+ // give a discovered check through an x-ray attack.
+ else if ( Piece == BISHOP
+ && (PseudoAttacks[Piece][pos.king_square(Them)] & s)
+ && !more_than_one(BetweenBB[s][pos.king_square(Them)] & pos.pieces()))
+ score += BishopPin;
- // Bishop and knight outposts squares
- if ((Piece == BISHOP || Piece == KNIGHT) && pos.square_is_weak(s, Us))
- bonus += evaluate_outposts<Piece, Us>(pos, ei, s);
+ // Penalty for bishop with same coloured pawns
+ if (Piece == BISHOP)
+ score -= BishopPawns * ei.pi->pawns_on_same_color_squares(Us, s);
+
+ if (Piece == BISHOP || Piece == KNIGHT)
+ {
+ // Bishop and knight outposts squares
+ if (!(pos.pieces(Them, PAWN) & pawn_attack_span(Us, s)))
+ score += evaluate_outposts<Piece, 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)
+ && relative_rank(Us, s) >= RANK_5)
{
- bonus += (Piece == ROOK ? RookOn7thBonus : QueenOn7thBonus);
+ // Major piece 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 += Piece == ROOK ? RookOn7th : QueenOn7th;
+
+ // Major piece attacking enemy pawns on the same rank/file
+ Bitboard pawns = pos.pieces(Them, PAWN) & PseudoAttacks[ROOK][s];
+ if (pawns)
+ score += popcount<Max15>(pawns) * (Piece == ROOK ? RookOnPawn : QueenOnPawn);
}
// 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))
- bonus += RookOpenFileBonus;
- else
- bonus += RookHalfOpenFileBonus;
- }
+ // 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;
- // 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(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)))
- bonus -= 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)))
- bonus -= make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2
- : (TrappedRookPenalty - mob * 16), 0);
- }
+ // Penalize rooks which are trapped inside a king. Penalize more if
+ // king has lost right to castle.
+ if ( ((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);
+ }
+
+ // 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 ( Piece == BISHOP
+ && pos.is_chess960()
+ && (s == relative_square(Us, SQ_A1) || s == relative_square(Us, SQ_H1)))
+ {
+ const enum Piece P = make_piece(Us, PAWN);
+ Square d = pawn_push(Us) + (file_of(s) == FILE_A ? DELTA_E : DELTA_W);
+ if (pos.piece_on(s + d) == P)
+ score -= !pos.empty(s + d + pawn_push(Us)) ? TrappedBishopA1H1 * 4
+ : pos.piece_on(s + d + d) == P ? TrappedBishopA1H1 * 2
+ : TrappedBishopA1H1;
}
}
- return bonus;
+
+ if (Trace)
+ Tracing::scores[Us][Piece] = score;
+
+ return score;
}
// evaluate_threats<>() assigns bonuses according to the type of attacking piece
// and the type of attacked one.
- template<Color Us>
- Score evaluate_threats(const Position& pos, EvalInfo& ei) {
+ template<Color Us, bool Trace>
+ Score evaluate_threats(const Position& pos, const EvalInfo& ei) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
- Bitboard b;
- Score bonus = SCORE_ZERO;
+ Bitboard b, undefendedMinors, weakEnemies;
+ Score score = SCORE_ZERO;
+
+ // Undefended minors get penalized even if 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
- Bitboard weakEnemies = pos.pieces_of_color(Them)
- & ~ei.attackedBy[Them][PAWN]
- & ei.attackedBy[Us][0];
- if (!weakEnemies)
- return SCORE_ZERO;
+ weakEnemies = pos.pieces(Them)
+ & ~ei.attackedBy[Them][PAWN]
+ & ei.attackedBy[Us][ALL_PIECES];
// 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))
- bonus += ThreatBonus[pt1][pt2];
- }
- return bonus;
+ if (weakEnemies)
+ 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 += Threat[pt1][pt2];
+ }
+
+ if (Trace)
+ Tracing::scores[Us][THREAT] = score;
+
+ return score;
}
// evaluate_pieces_of_color<>() assigns bonuses and penalties to all the
// pieces of a given color.
- template<Color Us, bool HasPopCnt>
+ template<Color Us, bool Trace>
Score evaluate_pieces_of_color(const Position& pos, EvalInfo& ei, Score& mobility) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
- Score bonus = mobility = SCORE_ZERO;
+ Score score = mobility = SCORE_ZERO;
// 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));
- bonus += evaluate_pieces<KNIGHT, Us, HasPopCnt>(pos, ei, mobility, no_mob_area);
- bonus += evaluate_pieces<BISHOP, Us, HasPopCnt>(pos, ei, mobility, no_mob_area);
- bonus += evaluate_pieces<ROOK, Us, HasPopCnt>(pos, ei, mobility, no_mob_area);
- bonus += evaluate_pieces<QUEEN, Us, HasPopCnt>(pos, ei, mobility, no_mob_area);
+ score += evaluate_pieces<KNIGHT, Us, Trace>(pos, ei, mobility, mobilityArea);
+ score += evaluate_pieces<BISHOP, Us, Trace>(pos, ei, mobility, mobilityArea);
+ score += evaluate_pieces<ROOK, Us, Trace>(pos, ei, mobility, mobilityArea);
+ score += evaluate_pieces<QUEEN, Us, Trace>(pos, ei, mobility, mobilityArea);
// Sum up all attacked squares
- ei.attackedBy[Us][0] = ei.attackedBy[Us][PAWN] | ei.attackedBy[Us][KNIGHT]
- | ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK]
- | ei.attackedBy[Us][QUEEN] | ei.attackedBy[Us][KING];
- return bonus;
+ 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::scores[Us][MOBILITY] = apply_weight(mobility, Weights[Mobility]);
+
+ return score;
}
// evaluate_king<>() assigns bonuses and penalties to a king of a given color
- template<Color Us, bool HasPopCnt>
- Score evaluate_king(const Position& pos, EvalInfo& ei, Value margins[]) {
+ template<Color Us, bool Trace>
+ Score evaluate_king(const Position& pos, const EvalInfo& ei, Value margins[]) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
int attackUnits;
const Square ksq = pos.king_square(Us);
- // King shelter
- Score bonus = ei.pi->king_shelter<Us>(pos, ksq);
+ // King shelter and enemy pawns storm
+ Score score = ei.pi->king_safety<Us>(pos, ksq);
// King safety. This is quite complicated, and is almost certainly far
// from optimally tuned.
- if ( ei.updateKingTables[Them]
- && ei.kingAttackersCount[Them] >= 2
+ if ( ei.kingAttackersCount[Them] >= 2
&& ei.kingAdjacentZoneAttacksCount[Them])
{
// Find the attacked squares around the king which has no defenders
// apart from the king itself
- undefended = ei.attackedBy[Them][0] & ei.attackedBy[Us][KING];
+ undefended = ei.attackedBy[Them][ALL_PIECES] & ei.attackedBy[Us][KING];
undefended &= ~( ei.attackedBy[Us][PAWN] | ei.attackedBy[Us][KNIGHT]
| ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK]
| ei.attackedBy[Us][QUEEN]);
// Initialize the 'attackUnits' variable, which is used later on as an
- // index to the KingDangerTable[] array. The initial value is based on
- // the number and types of the enemy's attacking pieces, the number of
+ // 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, 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, ksq)]
- - mg_value(ei.pi->king_shelter<Us>(pos, ksq)) / 32;
+ attackUnits = std::min(25, (ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) / 2)
+ + 3 * (ei.kingAdjacentZoneAttacksCount[Them] + popcount<Max15>(undefended))
+ + KingExposed[relative_square(Us, ksq)]
+ - mg_value(score) / 32;
// Analyse enemy's safe queen contact checks. First find undefended
// squares around the king attacked by enemy queen...
- b = undefended & ei.attackedBy[Them][QUEEN] & ~pos.pieces_of_color(Them);
+ b = undefended & ei.attackedBy[Them][QUEEN] & ~pos.pieces(Them);
if (b)
{
// ...then remove squares not supported by another enemy piece
b &= ( ei.attackedBy[Them][PAWN] | ei.attackedBy[Them][KNIGHT]
| ei.attackedBy[Them][BISHOP] | ei.attackedBy[Them][ROOK]);
if (b)
- attackUnits += QueenContactCheckBonus
- * count_1s_max_15<HasPopCnt>(b)
+ attackUnits += QueenContactCheck
+ * popcount<Max15>(b)
* (Them == pos.side_to_move() ? 2 : 1);
}
// Analyse enemy's safe rook contact checks. First find undefended
// squares around the king attacked by enemy rooks...
- b = undefended & ei.attackedBy[Them][ROOK] & ~pos.pieces_of_color(Them);
+ b = undefended & ei.attackedBy[Them][ROOK] & ~pos.pieces(Them);
// Consider only squares where the enemy rook gives check
- b &= RookPseudoAttacks[ksq];
+ b &= PseudoAttacks[ROOK][ksq];
if (b)
{
b &= ( ei.attackedBy[Them][PAWN] | ei.attackedBy[Them][KNIGHT]
| ei.attackedBy[Them][BISHOP] | ei.attackedBy[Them][QUEEN]);
if (b)
- attackUnits += RookContactCheckBonus
- * count_1s_max_15<HasPopCnt>(b)
+ attackUnits += RookContactCheck
+ * popcount<Max15>(b)
* (Them == pos.side_to_move() ? 2 : 1);
}
// Analyse enemy's safe distance checks for sliders and knights
- safe = ~(pos.pieces_of_color(Them) | ei.attackedBy[Us][0]);
+ safe = ~(pos.pieces(Them) | ei.attackedBy[Us][ALL_PIECES]);
b1 = pos.attacks_from<ROOK>(ksq) & safe;
b2 = pos.attacks_from<BISHOP>(ksq) & safe;
// Enemy queen safe checks
b = (b1 | b2) & ei.attackedBy[Them][QUEEN];
if (b)
- attackUnits += QueenCheckBonus * count_1s_max_15<HasPopCnt>(b);
+ attackUnits += QueenCheck * popcount<Max15>(b);
// Enemy rooks safe checks
b = b1 & ei.attackedBy[Them][ROOK];
if (b)
- attackUnits += RookCheckBonus * count_1s_max_15<HasPopCnt>(b);
+ attackUnits += RookCheck * popcount<Max15>(b);
// Enemy bishops safe checks
b = b2 & ei.attackedBy[Them][BISHOP];
if (b)
- attackUnits += BishopCheckBonus * count_1s_max_15<HasPopCnt>(b);
+ attackUnits += BishopCheck * popcount<Max15>(b);
// Enemy knights safe checks
b = pos.attacks_from<KNIGHT>(ksq) & ei.attackedBy[Them][KNIGHT] & safe;
if (b)
- attackUnits += KnightCheckBonus * count_1s_max_15<HasPopCnt>(b);
+ attackUnits += KnightCheck * popcount<Max15>(b);
- // To index KingDangerTable[] attackUnits must be in [0, 99] range
- attackUnits = Min(99, Max(0, attackUnits));
+ // 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 KingDangerTable[]
+ // Finally, extract the king danger score from the KingDanger[]
// 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.
- bonus -= KingDangerTable[Us][attackUnits];
- margins[Us] += mg_value(KingDangerTable[Us][attackUnits]);
+ score -= KingDanger[Us == Search::RootColor][attackUnits];
+ margins[Us] += mg_value(KingDanger[Us == Search::RootColor][attackUnits]);
}
- return bonus;
+
+ if (Trace)
+ Tracing::scores[Us][KING] = score;
+
+ return score;
}
// evaluate_passed_pawns<>() evaluates the passed pawns of the given color
- template<Color Us>
- Score 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);
- Score bonus = SCORE_ZERO;
- Bitboard squaresToQueen, defendedSquares, unsafeSquares, supportingPawns;
- Bitboard b = ei.pi->passed_pawns(Us);
+ Bitboard b, squaresToQueen, defendedSquares, unsafeSquares, supportingPawns;
+ Score score = SCORE_ZERO;
- if (!b)
- return SCORE_ZERO;
+ b = ei.pi->passed_pawns(Us);
- do {
- Square s = pop_1st_bit(&b);
+ while (b)
+ {
+ Square s = pop_lsb(&b);
- assert(pos.pawn_is_passed(Us, s));
+ assert(pos.pawn_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));
+ Value mbonus = Value(17 * rr);
+ Value ebonus = Value(7 * (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);
+ ebonus += Value(square_distance(pos.king_square(Them), blockSq) * 5 * rr)
+ - Value(square_distance(pos.king_square(Us ), blockSq) * 2 * rr);
+
+ // If blockSq is not the queening square then consider also a second push
+ if (relative_rank(Us, blockSq) != RANK_8)
+ ebonus -= Value(square_distance(pos.king_square(Us), blockSq + pawn_push(Us)) * rr);
// If the pawn is free to advance, increase bonus
- if (pos.square_is_empty(blockSq))
+ if (pos.empty(blockSq))
{
- squaresToQueen = squares_in_front_of(Us, s);
- defendedSquares = squaresToQueen & ei.attackedBy[Us][0];
+ squaresToQueen = forward_bb(Us, s);
// If there is an enemy rook or queen attacking the pawn from behind,
// add all X-ray attacks by the rook or queen. Otherwise consider only
// the squares in the pawn's path attacked or occupied by the enemy.
- if ( (squares_behind(Us, s) & pos.pieces(ROOK, QUEEN, Them))
- && (squares_behind(Us, s) & pos.pieces(ROOK, QUEEN, Them) & pos.attacks_from<ROOK>(s)))
+ 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][0] | pos.pieces_of_color(Them));
+ unsafeSquares = squaresToQueen & (ei.attackedBy[Them][ALL_PIECES] | pos.pieces(Them));
- // If there aren't enemy attacks or pieces along the path to queen give
- // huge bonus. Even bigger if we protect the pawn's path.
- if (!unsafeSquares)
- ebonus += Value(rr * (squaresToQueen == defendedSquares ? 17 : 15));
+ 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
- // 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);
+ defendedSquares = squaresToQueen & ei.attackedBy[Us][ALL_PIECES];
+
+ // If there aren't enemy attacks huge bonus, a bit smaller if at
+ // least block square is not attacked, otherwise smallest bonus.
+ int k = !unsafeSquares ? 15 : !(unsafeSquares & blockSq) ? 9 : 3;
+
+ // Big bonus if the path to queen is fully defended, a bit less
+ // if at least 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);
}
} // 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);
+ supportingPawns = pos.pieces(Us, PAWN) & adjacent_files_bb(file_of(s));
if (supportingPawns & rank_bb(s))
ebonus += Value(r * 20);
+
else if (supportingPawns & rank_bb(s - pawn_push(Us)))
ebonus += Value(r * 12);
// 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)
+ if (pos.non_pawn_material(Them) <= KnightValueMg)
ebonus += ebonus / 4;
- else if (pos.pieces(ROOK, QUEEN, Them))
+
+ else if (pos.pieces(Them, ROOK, QUEEN))
ebonus -= ebonus / 4;
}
- bonus += make_score(mbonus, ebonus);
- } while (b);
+ // Increase the bonus if we have more non-pawn pieces
+ if (pos.count<ALL_PIECES>( Us) - pos.count<PAWN>( Us) >
+ pos.count<ALL_PIECES>(Them) - pos.count<PAWN>(Them))
+ ebonus += ebonus / 4;
+
+ score += make_score(mbonus, ebonus);
+
+ }
+
+ if (Trace)
+ Tracing::scores[Us][PASSED] = apply_weight(score, Weights[PassedPawns]);
// Add the scores to the middle game and endgame eval
- return apply_weight(bonus, Weights[PassedPawns]);
+ return apply_weight(score, Weights[PassedPawns]);
+ }
+
+
+ // 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 pawns are unstoppable.
+
+ Score evaluate_unstoppable_pawns(const Position& pos, Color us, const EvalInfo& ei) {
+
+ Bitboard b = ei.pi->passed_pawns(us) | ei.pi->candidate_pawns(us);
+
+ if (!b || pos.non_pawn_material(~us))
+ return SCORE_ZERO;
+
+ return Unstoppable * int(relative_rank(us, frontmost_sq(us, b)));
}
// squares one, two or three squares behind a friendly pawn are counted
// twice. Finally, the space bonus is scaled by a weight taken from the
// material hash table. The aim is to improve play on game opening.
- template<Color Us, bool HasPopCnt>
- int evaluate_space(const Position& pos, EvalInfo& ei) {
+ template<Color Us>
+ int evaluate_space(const Position& pos, const EvalInfo& ei) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
// 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_max_15<HasPopCnt>(safe) + count_1s_max_15<HasPopCnt>(behind & safe);
- }
-
-
- // apply_weight() applies an evaluation weight to a value trying to prevent overflow
+ // Since SpaceMask[Us] is fully on our half of the board
+ assert(unsigned(safe >> (Us == WHITE ? 32 : 0)) == 0);
- 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);
+ // Count safe + (behind & safe) with a single popcount
+ return popcount<Full>((Us == WHITE ? safe << 32 : safe >> 32) | (behind & safe));
}
- // scale_by_game_phase() interpolates between a middle game and an endgame score,
+ // interpolate() interpolates between a middle game and an endgame score,
// based on game phase. It also scales the return value by a ScaleFactor array.
- Value scale_by_game_phase(const Score& v, Phase ph, const ScaleFactor sf[]) {
+ Value interpolate(const Score& v, Phase ph, ScaleFactor sf) {
assert(mg_value(v) > -VALUE_INFINITE && mg_value(v) < VALUE_INFINITE);
assert(eg_value(v) > -VALUE_INFINITE && eg_value(v) < VALUE_INFINITE);
assert(ph >= PHASE_ENDGAME && ph <= PHASE_MIDGAME);
- Value eg = eg_value(v);
- ScaleFactor f = sf[eg > VALUE_ZERO ? WHITE : BLACK];
- Value ev = Value((eg * int(f)) / SCALE_FACTOR_NORMAL);
-
- int result = (mg_value(v) * int(ph) + ev * int(128 - ph)) / 128;
- return Value(result & ~(GrainSize - 1));
+ int e = (eg_value(v) * int(sf)) / SCALE_FACTOR_NORMAL;
+ int r = (mg_value(v) * int(ph) + e * int(PHASE_MIDGAME - ph)) / PHASE_MIDGAME;
+ return Value((r / GrainSize) * GrainSize); // Sign independent
}
+ // apply_weight() weights score v by score w trying to prevent overflow
+ 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);
+ }
// weight_option() computes the value of an evaluation weight, by combining
// two UCI-configurable weights (midgame and endgame) with an internal weight.
Score weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight) {
// Scale option value from 100 to 256
- int mg = get_option_value_int(mgOpt) * 256 / 100;
- int eg = get_option_value_int(egOpt) * 256 / 100;
+ int mg = Options[mgOpt] * 256 / 100;
+ int eg = Options[egOpt] * 256 / 100;
return apply_weight(make_score(mg, eg), internalWeight);
}
- // init_safety() initizes the king safety evaluation, based on UCI
- // parameters. It is called from read_weights().
+ // Tracing functions definitions
- void init_safety() {
+ double to_cp(Value v) { return double(v) / double(PawnValueMg); }
- const Value MaxSlope = Value(30);
- const Value Peak = Value(1280);
- Value t[100];
-
- // First setup the base table
- for (int i = 0; i < 100; i++)
- {
- t[i] = Value(int(0.4 * i * i));
+ void Tracing::add(int idx, Score wScore, Score bScore) {
- if (i > 0)
- t[i] = Min(t[i], t[i - 1] + MaxSlope);
+ scores[WHITE][idx] = wScore;
+ scores[BLACK][idx] = bScore;
+ }
- t[i] = Min(t[i], Peak);
+ void Tracing::row(const char* name, int idx) {
+
+ Score wScore = scores[WHITE][idx];
+ Score bScore = scores[BLACK][idx];
+
+ switch (idx) {
+ case PST: case IMBALANCE: case PAWN: case TOTAL:
+ stream << std::setw(20) << name << " | --- --- | --- --- | "
+ << std::setw(6) << to_cp(mg_value(wScore)) << " "
+ << std::setw(6) << to_cp(eg_value(wScore)) << " \n";
+ break;
+ default:
+ stream << 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";
}
+ }
+
+ std::string Tracing::do_trace(const Position& pos) {
+
+ stream.str("");
+ stream << std::showpoint << std::showpos << std::fixed << std::setprecision(2);
+ std::memset(scores, 0, 2 * (TOTAL + 1) * sizeof(Score));
+
+ Value margin;
+ do_evaluate<true>(pos, margin);
+
+ std::string totals = stream.str();
+ stream.str("");
+
+ stream << std::setw(21) << "Eval term " << "| White | Black | Total \n"
+ << " | MG EG | MG EG | MG EG \n"
+ << "---------------------+-------------+-------------+---------------\n";
+
+ row("Material, PST, Tempo", PST);
+ row("Material imbalance", IMBALANCE);
+ row("Pawns", PAWN);
+ row("Knights", KNIGHT);
+ row("Bishops", BISHOP);
+ row("Rooks", ROOK);
+ row("Queens", QUEEN);
+ row("Mobility", MOBILITY);
+ row("King safety", KING);
+ row("Threats", THREAT);
+ row("Passed pawns", PASSED);
+ row("Space", SPACE);
+
+ stream << "---------------------+-------------+-------------+---------------\n";
+ row("Total", TOTAL);
+ stream << totals;
- // 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 stream.str();
}
}