2 Stockfish, a UCI chess playing engine derived from Glaurung 2.1
3 Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
4 Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
6 Stockfish is free software: you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation, either version 3 of the License, or
9 (at your option) any later version.
11 Stockfish is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>.
30 #include "ucioption.h"
34 // Struct EvalInfo contains various information computed and collected
35 // by the evaluation functions.
38 // Pointers to material and pawn hash table entries
42 // attackedBy[color][piece type] is a bitboard representing all squares
43 // attacked by a given color and piece type, attackedBy[color][0] contains
44 // all squares attacked by the given color.
45 Bitboard attackedBy[COLOR_NB][PIECE_TYPE_NB];
47 // kingRing[color] is the zone around the king which is considered
48 // by the king safety evaluation. This consists of the squares directly
49 // adjacent to the king, and the three (or two, for a king on an edge file)
50 // squares two ranks in front of the king. For instance, if black's king
51 // is on g8, kingRing[BLACK] is a bitboard containing the squares f8, h8,
52 // f7, g7, h7, f6, g6 and h6.
53 Bitboard kingRing[COLOR_NB];
55 // kingAttackersCount[color] is the number of pieces of the given color
56 // which attack a square in the kingRing of the enemy king.
57 int kingAttackersCount[COLOR_NB];
59 // kingAttackersWeight[color] is the sum of the "weight" of the pieces of the
60 // given color which attack a square in the kingRing of the enemy king. The
61 // weights of the individual piece types are given by the variables
62 // QueenAttackWeight, RookAttackWeight, BishopAttackWeight and
63 // KnightAttackWeight in evaluate.cpp
64 int kingAttackersWeight[COLOR_NB];
66 // kingAdjacentZoneAttacksCount[color] is the number of attacks to squares
67 // directly adjacent to the king of the given color. Pieces which attack
68 // more than one square are counted multiple times. For instance, if black's
69 // king is on g8 and there's a white knight on g5, this knight adds
70 // 2 to kingAdjacentZoneAttacksCount[BLACK].
71 int kingAdjacentZoneAttacksCount[COLOR_NB];
74 // Evaluation grain size, must be a power of 2
75 const int GrainSize = 8;
77 // Evaluation weights, initialized from UCI options
78 enum { Mobility, PassedPawns, Space, KingDangerUs, KingDangerThem };
82 #define S(mg, eg) make_score(mg, eg)
84 // Internal evaluation weights. These are applied on top of the evaluation
85 // weights read from UCI parameters. The purpose is to be able to change
86 // the evaluation weights while keeping the default values of the UCI
87 // parameters at 100, which looks prettier.
89 // Values modified by Joona Kiiski
90 const Score WeightsInternal[] = {
91 S(252, 344), S(216, 266), S(46, 0), S(247, 0), S(259, 0)
94 // MobilityBonus[PieceType][attacked] contains mobility bonuses for middle and
95 // end game, indexed by piece type and number of attacked squares not occupied
96 // by friendly pieces.
97 const Score MobilityBonus[][32] = {
99 { S(-38,-33), S(-25,-23), S(-12,-13), S( 0, -3), S(12, 7), S(25, 17), // Knights
100 S( 31, 22), S( 38, 27), S( 38, 27) },
101 { S(-25,-30), S(-11,-16), S( 3, -2), S(17, 12), S(31, 26), S(45, 40), // Bishops
102 S( 57, 52), S( 65, 60), S( 71, 65), S(74, 69), S(76, 71), S(78, 73),
103 S( 79, 74), S( 80, 75), S( 81, 76), S(81, 76) },
104 { S(-20,-36), S(-14,-19), S( -8, -3), S(-2, 13), S( 4, 29), S(10, 46), // Rooks
105 S( 14, 62), S( 19, 79), S( 23, 95), S(26,106), S(27,111), S(28,114),
106 S( 29,116), S( 30,117), S( 31,118), S(32,118) },
107 { S(-10,-18), S( -8,-13), S( -6, -7), S(-3, -2), S(-1, 3), S( 1, 8), // Queens
108 S( 3, 13), S( 5, 19), S( 8, 23), S(10, 27), S(12, 32), S(15, 34),
109 S( 16, 35), S( 17, 35), S( 18, 35), S(20, 35), S(20, 35), S(20, 35),
110 S( 20, 35), S( 20, 35), S( 20, 35), S(20, 35), S(20, 35), S(20, 35),
111 S( 20, 35), S( 20, 35), S( 20, 35), S(20, 35), S(20, 35), S(20, 35),
112 S( 20, 35), S( 20, 35) }
115 // OutpostBonus[PieceType][Square] contains outpost bonuses of knights and
116 // bishops, indexed by piece type and square (from white's point of view).
117 const Value OutpostBonus[][SQUARE_NB] = {
120 V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // Knights
121 V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0),
122 V(0), V(0), V(4), V(8), V(8), V(4), V(0), V(0),
123 V(0), V(4),V(17),V(26),V(26),V(17), V(4), V(0),
124 V(0), V(8),V(26),V(35),V(35),V(26), V(8), V(0),
125 V(0), V(4),V(17),V(17),V(17),V(17), V(4), V(0) },
127 V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // Bishops
128 V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0),
129 V(0), V(0), V(5), V(5), V(5), V(5), V(0), V(0),
130 V(0), V(5),V(10),V(10),V(10),V(10), V(5), V(0),
131 V(0),V(10),V(21),V(21),V(21),V(21),V(10), V(0),
132 V(0), V(5), V(8), V(8), V(8), V(8), V(5), V(0) }
135 // ThreatBonus[attacking][attacked] contains threat bonuses according to
136 // which piece type attacks which one.
137 const Score ThreatBonus[][PIECE_TYPE_NB] = {
139 { S(0, 0), S( 7, 39), S( 0, 0), S(24, 49), S(41,100), S(41,100) }, // KNIGHT
140 { S(0, 0), S( 7, 39), S(24, 49), S( 0, 0), S(41,100), S(41,100) }, // BISHOP
141 { S(0, 0), S( 0, 22), S(15, 49), S(15, 49), S( 0, 0), S(24, 49) }, // ROOK
142 { S(0, 0), S(15, 39), S(15, 39), S(15, 39), S(15, 39), S( 0, 0) } // QUEEN
145 // ThreatenedByPawnPenalty[PieceType] contains a penalty according to which
146 // piece type is attacked by an enemy pawn.
147 const Score ThreatenedByPawnPenalty[] = {
148 S(0, 0), S(0, 0), S(56, 70), S(56, 70), S(76, 99), S(86, 118)
153 // Bonus for having the side to move (modified by Joona Kiiski)
154 const Score Tempo = make_score(24, 11);
156 // Rooks and queens on the 7th rank
157 const Score RookOn7thBonus = make_score(3, 20);
158 const Score QueenOn7thBonus = make_score(1, 8);
160 // Rooks and queens attacking pawns on the same rank
161 const Score RookOnPawnBonus = make_score(3, 48);
162 const Score QueenOnPawnBonus = make_score(1, 40);
164 // Rooks on open files (modified by Joona Kiiski)
165 const Score RookOpenFileBonus = make_score(43, 21);
166 const Score RookHalfOpenFileBonus = make_score(19, 10);
168 // Penalty for rooks trapped inside a friendly king which has lost the
170 const Value TrappedRookPenalty = Value(180);
172 // Penalty for a bishop on a1/h1 (a8/h8 for black) which is trapped by
173 // a friendly pawn on b2/g2 (b7/g7 for black). This can obviously only
174 // happen in Chess960 games.
175 const Score TrappedBishopA1H1Penalty = make_score(100, 100);
177 // Penalty for an undefended bishop or knight
178 const Score UndefendedMinorPenalty = make_score(25, 10);
180 // The SpaceMask[Color] contains the area of the board which is considered
181 // by the space evaluation. In the middle game, each side is given a bonus
182 // based on how many squares inside this area are safe and available for
183 // friendly minor pieces.
184 const Bitboard SpaceMask[] = {
185 (1ULL << SQ_C2) | (1ULL << SQ_D2) | (1ULL << SQ_E2) | (1ULL << SQ_F2) |
186 (1ULL << SQ_C3) | (1ULL << SQ_D3) | (1ULL << SQ_E3) | (1ULL << SQ_F3) |
187 (1ULL << SQ_C4) | (1ULL << SQ_D4) | (1ULL << SQ_E4) | (1ULL << SQ_F4),
188 (1ULL << SQ_C7) | (1ULL << SQ_D7) | (1ULL << SQ_E7) | (1ULL << SQ_F7) |
189 (1ULL << SQ_C6) | (1ULL << SQ_D6) | (1ULL << SQ_E6) | (1ULL << SQ_F6) |
190 (1ULL << SQ_C5) | (1ULL << SQ_D5) | (1ULL << SQ_E5) | (1ULL << SQ_F5)
193 // King danger constants and variables. The king danger scores are taken
194 // from the KingDangerTable[]. Various little "meta-bonuses" measuring
195 // the strength of the enemy attack are added up into an integer, which
196 // is used as an index to KingDangerTable[].
198 // KingAttackWeights[PieceType] contains king attack weights by piece type
199 const int KingAttackWeights[] = { 0, 0, 2, 2, 3, 5 };
201 // Bonuses for enemy's safe checks
202 const int QueenContactCheckBonus = 6;
203 const int RookContactCheckBonus = 4;
204 const int QueenCheckBonus = 3;
205 const int RookCheckBonus = 2;
206 const int BishopCheckBonus = 1;
207 const int KnightCheckBonus = 1;
209 // InitKingDanger[Square] contains penalties based on the position of the
210 // defending king, indexed by king's square (from white's point of view).
211 const int InitKingDanger[] = {
212 2, 0, 2, 5, 5, 2, 0, 2,
213 2, 2, 4, 8, 8, 4, 2, 2,
214 7, 10, 12, 12, 12, 12, 10, 7,
215 15, 15, 15, 15, 15, 15, 15, 15,
216 15, 15, 15, 15, 15, 15, 15, 15,
217 15, 15, 15, 15, 15, 15, 15, 15,
218 15, 15, 15, 15, 15, 15, 15, 15,
219 15, 15, 15, 15, 15, 15, 15, 15
222 // KingDangerTable[Color][attackUnits] contains the actual king danger
223 // weighted scores, indexed by color and by a calculated integer number.
224 Score KingDangerTable[COLOR_NB][128];
226 // TracedTerms[Color][PieceType || TracedType] contains a breakdown of the
227 // evaluation terms, used when tracing.
228 Score TracedScores[COLOR_NB][16];
229 std::stringstream TraceStream;
232 PST = 8, IMBALANCE = 9, MOBILITY = 10, THREAT = 11,
233 PASSED = 12, UNSTOPPABLE = 13, SPACE = 14, TOTAL = 15
236 // Function prototypes
238 Value do_evaluate(const Position& pos, Value& margin);
241 void init_eval_info(const Position& pos, EvalInfo& ei);
243 template<Color Us, bool Trace>
244 Score evaluate_pieces_of_color(const Position& pos, EvalInfo& ei, Score& mobility);
246 template<Color Us, bool Trace>
247 Score evaluate_king(const Position& pos, EvalInfo& ei, Value margins[]);
250 Score evaluate_threats(const Position& pos, EvalInfo& ei);
253 int evaluate_space(const Position& pos, EvalInfo& ei);
256 Score evaluate_passed_pawns(const Position& pos, EvalInfo& ei);
258 Score evaluate_unstoppable_pawns(const Position& pos, EvalInfo& ei);
260 Value interpolate(const Score& v, Phase ph, ScaleFactor sf);
261 Score weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight);
262 double to_cp(Value v);
263 void trace_add(int idx, Score term_w, Score term_b = SCORE_ZERO);
264 void trace_row(const char* name, int idx);
270 /// evaluate() is the main evaluation function. It always computes two
271 /// values, an endgame score and a middle game score, and interpolates
272 /// between them based on the remaining material.
274 Value evaluate(const Position& pos, Value& margin) {
275 return do_evaluate<false>(pos, margin);
279 /// init() computes evaluation weights from the corresponding UCI parameters
280 /// and setup king tables.
284 Weights[Mobility] = weight_option("Mobility (Middle Game)", "Mobility (Endgame)", WeightsInternal[Mobility]);
285 Weights[PassedPawns] = weight_option("Passed Pawns (Middle Game)", "Passed Pawns (Endgame)", WeightsInternal[PassedPawns]);
286 Weights[Space] = weight_option("Space", "Space", WeightsInternal[Space]);
287 Weights[KingDangerUs] = weight_option("Cowardice", "Cowardice", WeightsInternal[KingDangerUs]);
288 Weights[KingDangerThem] = weight_option("Aggressiveness", "Aggressiveness", WeightsInternal[KingDangerThem]);
290 // King safety is asymmetrical. Our king danger level is weighted by
291 // "Cowardice" UCI parameter, instead the opponent one by "Aggressiveness".
292 // If running in analysis mode, make sure we use symmetrical king safety. We
293 // do this by replacing both Weights[kingDangerUs] and Weights[kingDangerThem]
295 if (Options["UCI_AnalyseMode"])
296 Weights[KingDangerUs] = Weights[KingDangerThem] = (Weights[KingDangerUs] + Weights[KingDangerThem]) / 2;
298 const int MaxSlope = 30;
299 const int Peak = 1280;
301 for (int t = 0, i = 1; i < 100; i++)
303 t = std::min(Peak, std::min(int(0.4 * i * i), t + MaxSlope));
305 KingDangerTable[1][i] = apply_weight(make_score(t, 0), Weights[KingDangerUs]);
306 KingDangerTable[0][i] = apply_weight(make_score(t, 0), Weights[KingDangerThem]);
311 /// trace() is like evaluate() but instead of a value returns a string suitable
312 /// to be print on stdout with the detailed descriptions and values of each
313 /// evaluation term. Used mainly for debugging.
315 std::string trace(const Position& pos) {
320 Search::RootColor = pos.side_to_move();
323 TraceStream << std::showpoint << std::showpos << std::fixed << std::setprecision(2);
324 memset(TracedScores, 0, 2 * 16 * sizeof(Score));
326 do_evaluate<true>(pos, margin);
328 totals = TraceStream.str();
331 TraceStream << std::setw(21) << "Eval term " << "| White | Black | Total \n"
332 << " | MG EG | MG EG | MG EG \n"
333 << "---------------------+-------------+-------------+---------------\n";
335 trace_row("Material, PST, Tempo", PST);
336 trace_row("Material imbalance", IMBALANCE);
337 trace_row("Pawns", PAWN);
338 trace_row("Knights", KNIGHT);
339 trace_row("Bishops", BISHOP);
340 trace_row("Rooks", ROOK);
341 trace_row("Queens", QUEEN);
342 trace_row("Mobility", MOBILITY);
343 trace_row("King safety", KING);
344 trace_row("Threats", THREAT);
345 trace_row("Passed pawns", PASSED);
346 trace_row("Unstoppable pawns", UNSTOPPABLE);
347 trace_row("Space", SPACE);
349 TraceStream << "---------------------+-------------+-------------+---------------\n";
350 trace_row("Total", TOTAL);
351 TraceStream << totals;
353 return TraceStream.str();
362 Value do_evaluate(const Position& pos, Value& margin) {
364 assert(!pos.in_check());
367 Value margins[COLOR_NB];
368 Score score, mobilityWhite, mobilityBlack;
370 // margins[] store the uncertainty estimation of position's evaluation
371 // that typically is used by the search for pruning decisions.
372 margins[WHITE] = margins[BLACK] = VALUE_ZERO;
374 // Initialize score by reading the incrementally updated scores included
375 // in the position object (material + piece square tables) and adding
376 // Tempo bonus. Score is computed from the point of view of white.
377 score = pos.psq_score() + (pos.side_to_move() == WHITE ? Tempo : -Tempo);
379 // Probe the material hash table
380 ei.mi = pos.this_thread()->materialTable.probe(pos);
381 score += ei.mi->material_value();
383 // If we have a specialized evaluation function for the current material
384 // configuration, call it and return.
385 if (ei.mi->specialized_eval_exists())
388 return ei.mi->evaluate(pos);
391 // Probe the pawn hash table
392 ei.pi = pos.this_thread()->pawnTable.probe(pos);
393 score += ei.pi->pawns_value();
395 // Initialize attack and king safety bitboards
396 init_eval_info<WHITE>(pos, ei);
397 init_eval_info<BLACK>(pos, ei);
399 // Evaluate pieces and mobility
400 score += evaluate_pieces_of_color<WHITE, Trace>(pos, ei, mobilityWhite)
401 - evaluate_pieces_of_color<BLACK, Trace>(pos, ei, mobilityBlack);
403 score += apply_weight(mobilityWhite - mobilityBlack, Weights[Mobility]);
405 // Evaluate kings after all other pieces because we need complete attack
406 // information when computing the king safety evaluation.
407 score += evaluate_king<WHITE, Trace>(pos, ei, margins)
408 - evaluate_king<BLACK, Trace>(pos, ei, margins);
410 // Evaluate tactical threats, we need full attack information including king
411 score += evaluate_threats<WHITE>(pos, ei)
412 - evaluate_threats<BLACK>(pos, ei);
414 // Evaluate passed pawns, we need full attack information including king
415 score += evaluate_passed_pawns<WHITE>(pos, ei)
416 - evaluate_passed_pawns<BLACK>(pos, ei);
418 // If one side has only a king, check whether exists any unstoppable passed pawn
419 if (!pos.non_pawn_material(WHITE) || !pos.non_pawn_material(BLACK))
420 score += evaluate_unstoppable_pawns(pos, ei);
422 // Evaluate space for both sides, only in middle-game.
423 if (ei.mi->space_weight())
425 int s = evaluate_space<WHITE>(pos, ei) - evaluate_space<BLACK>(pos, ei);
426 score += apply_weight(make_score(s * ei.mi->space_weight(), 0), Weights[Space]);
429 // Scale winning side if position is more drawish that what it appears
430 ScaleFactor sf = eg_value(score) > VALUE_DRAW ? ei.mi->scale_factor(pos, WHITE)
431 : ei.mi->scale_factor(pos, BLACK);
433 // If we don't already have an unusual scale factor, check for opposite
434 // colored bishop endgames, and use a lower scale for those.
435 if ( ei.mi->game_phase() < PHASE_MIDGAME
436 && pos.opposite_bishops()
437 && sf == SCALE_FACTOR_NORMAL)
439 // Only the two bishops ?
440 if ( pos.non_pawn_material(WHITE) == BishopValueMg
441 && pos.non_pawn_material(BLACK) == BishopValueMg)
443 // Check for KBP vs KB with only a single pawn that is almost
444 // certainly a draw or at least two pawns.
445 bool one_pawn = (pos.piece_count(WHITE, PAWN) + pos.piece_count(BLACK, PAWN) == 1);
446 sf = one_pawn ? ScaleFactor(8) : ScaleFactor(32);
449 // Endgame with opposite-colored bishops, but also other pieces. Still
450 // a bit drawish, but not as drawish as with only the two bishops.
451 sf = ScaleFactor(50);
454 margin = margins[pos.side_to_move()];
455 Value v = interpolate(score, ei.mi->game_phase(), sf);
457 // In case of tracing add all single evaluation contributions for both white and black
460 trace_add(PST, pos.psq_score());
461 trace_add(IMBALANCE, ei.mi->material_value());
462 trace_add(PAWN, ei.pi->pawns_value());
463 trace_add(MOBILITY, apply_weight(mobilityWhite, Weights[Mobility]), apply_weight(mobilityBlack, Weights[Mobility]));
464 trace_add(THREAT, evaluate_threats<WHITE>(pos, ei), evaluate_threats<BLACK>(pos, ei));
465 trace_add(PASSED, evaluate_passed_pawns<WHITE>(pos, ei), evaluate_passed_pawns<BLACK>(pos, ei));
466 trace_add(UNSTOPPABLE, evaluate_unstoppable_pawns(pos, ei));
467 Score w = make_score(ei.mi->space_weight() * evaluate_space<WHITE>(pos, ei), 0);
468 Score b = make_score(ei.mi->space_weight() * evaluate_space<BLACK>(pos, ei), 0);
469 trace_add(SPACE, apply_weight(w, Weights[Space]), apply_weight(b, Weights[Space]));
470 trace_add(TOTAL, score);
471 TraceStream << "\nUncertainty margin: White: " << to_cp(margins[WHITE])
472 << ", Black: " << to_cp(margins[BLACK])
473 << "\nScaling: " << std::noshowpos
474 << std::setw(6) << 100.0 * ei.mi->game_phase() / 128.0 << "% MG, "
475 << std::setw(6) << 100.0 * (1.0 - ei.mi->game_phase() / 128.0) << "% * "
476 << std::setw(6) << (100.0 * sf) / SCALE_FACTOR_NORMAL << "% EG.\n"
477 << "Total evaluation: " << to_cp(v);
480 return pos.side_to_move() == WHITE ? v : -v;
484 // init_eval_info() initializes king bitboards for given color adding
485 // pawn attacks. To be done at the beginning of the evaluation.
488 void init_eval_info(const Position& pos, EvalInfo& ei) {
490 const Color Them = (Us == WHITE ? BLACK : WHITE);
492 Bitboard b = ei.attackedBy[Them][KING] = pos.attacks_from<KING>(pos.king_square(Them));
493 ei.attackedBy[Us][PAWN] = ei.pi->pawn_attacks(Us);
495 // Init king safety tables only if we are going to use them
496 if ( pos.piece_count(Us, QUEEN)
497 && pos.non_pawn_material(Us) >= QueenValueMg + RookValueMg)
499 ei.kingRing[Them] = (b | (Us == WHITE ? b >> 8 : b << 8));
500 b &= ei.attackedBy[Us][PAWN];
501 ei.kingAttackersCount[Us] = b ? popcount<Max15>(b) / 2 : 0;
502 ei.kingAdjacentZoneAttacksCount[Us] = ei.kingAttackersWeight[Us] = 0;
504 ei.kingRing[Them] = ei.kingAttackersCount[Us] = 0;
508 // evaluate_outposts() evaluates bishop and knight outposts squares
510 template<PieceType Piece, Color Us>
511 Score evaluate_outposts(const Position& pos, EvalInfo& ei, Square s) {
513 const Color Them = (Us == WHITE ? BLACK : WHITE);
515 assert (Piece == BISHOP || Piece == KNIGHT);
517 // Initial bonus based on square
518 Value bonus = OutpostBonus[Piece == BISHOP][relative_square(Us, s)];
520 // Increase bonus if supported by pawn, especially if the opponent has
521 // no minor piece which can exchange the outpost piece.
522 if (bonus && (ei.attackedBy[Us][PAWN] & s))
524 if ( !pos.pieces(Them, KNIGHT)
525 && !(same_color_squares(s) & pos.pieces(Them, BISHOP)))
526 bonus += bonus + bonus / 2;
530 return make_score(bonus, bonus);
534 // evaluate_pieces<>() assigns bonuses and penalties to the pieces of a given color
536 template<PieceType Piece, Color Us, bool Trace>
537 Score evaluate_pieces(const Position& pos, EvalInfo& ei, Score& mobility, Bitboard mobilityArea) {
543 Score score = SCORE_ZERO;
545 const Color Them = (Us == WHITE ? BLACK : WHITE);
546 const Square* pl = pos.piece_list(Us, Piece);
548 ei.attackedBy[Us][Piece] = 0;
550 while ((s = *pl++) != SQ_NONE)
552 // Find attacked squares, including x-ray attacks for bishops and rooks
553 if (Piece == KNIGHT || Piece == QUEEN)
554 b = pos.attacks_from<Piece>(s);
555 else if (Piece == BISHOP)
556 b = attacks_bb<BISHOP>(s, pos.pieces() ^ pos.pieces(Us, QUEEN));
557 else if (Piece == ROOK)
558 b = attacks_bb<ROOK>(s, pos.pieces() ^ pos.pieces(Us, ROOK, QUEEN));
562 ei.attackedBy[Us][Piece] |= b;
564 if (b & ei.kingRing[Them])
566 ei.kingAttackersCount[Us]++;
567 ei.kingAttackersWeight[Us] += KingAttackWeights[Piece];
568 Bitboard bb = (b & ei.attackedBy[Them][KING]);
570 ei.kingAdjacentZoneAttacksCount[Us] += popcount<Max15>(bb);
573 mob = (Piece != QUEEN ? popcount<Max15>(b & mobilityArea)
574 : popcount<Full >(b & mobilityArea));
576 mobility += MobilityBonus[Piece][mob];
578 // Add a bonus if a slider is pinning an enemy piece
579 if ( (Piece == BISHOP || Piece == ROOK || Piece == QUEEN)
580 && (PseudoAttacks[Piece][pos.king_square(Them)] & s))
582 b = BetweenBB[s][pos.king_square(Them)] & pos.pieces();
586 if (!more_than_one(b) && (b & pos.pieces(Them)))
587 score += ThreatBonus[Piece][type_of(pos.piece_on(lsb(b)))];
590 // Decrease score if we are attacked by an enemy pawn. Remaining part
591 // of threat evaluation must be done later when we have full attack info.
592 if (ei.attackedBy[Them][PAWN] & s)
593 score -= ThreatenedByPawnPenalty[Piece];
595 // Bishop and knight outposts squares
596 if ( (Piece == BISHOP || Piece == KNIGHT)
597 && !(pos.pieces(Them, PAWN) & attack_span_mask(Us, s)))
598 score += evaluate_outposts<Piece, Us>(pos, ei, s);
600 if ((Piece == ROOK || Piece == QUEEN) && relative_rank(Us, s) >= RANK_5)
602 // Major piece on 7th rank
603 if ( relative_rank(Us, s) == RANK_7
604 && relative_rank(Us, pos.king_square(Them)) == RANK_8)
605 score += (Piece == ROOK ? RookOn7thBonus : QueenOn7thBonus);
607 // Major piece attacking pawns on the same rank
608 Bitboard pawns = pos.pieces(Them, PAWN) & rank_bb(s);
610 score += (Piece == ROOK ? RookOnPawnBonus
611 : QueenOnPawnBonus) * popcount<Max15>(pawns);
614 // Special extra evaluation for bishops
615 if (Piece == BISHOP && pos.is_chess960())
617 // An important Chess960 pattern: A cornered bishop blocked by
618 // a friendly pawn diagonally in front of it is a very serious
619 // problem, especially when that pawn is also blocked.
620 if (s == relative_square(Us, SQ_A1) || s == relative_square(Us, SQ_H1))
622 Square d = pawn_push(Us) + (file_of(s) == FILE_A ? DELTA_E : DELTA_W);
623 if (pos.piece_on(s + d) == make_piece(Us, PAWN))
625 if (!pos.is_empty(s + d + pawn_push(Us)))
626 score -= 2*TrappedBishopA1H1Penalty;
627 else if (pos.piece_on(s + 2*d) == make_piece(Us, PAWN))
628 score -= TrappedBishopA1H1Penalty;
630 score -= TrappedBishopA1H1Penalty / 2;
635 // Special extra evaluation for rooks
638 // Open and half-open files
640 if (ei.pi->file_is_half_open(Us, f))
642 if (ei.pi->file_is_half_open(Them, f))
643 score += RookOpenFileBonus;
645 score += RookHalfOpenFileBonus;
648 // Penalize rooks which are trapped inside a king. Penalize more if
649 // king has lost right to castle.
650 if (mob > 6 || ei.pi->file_is_half_open(Us, f))
653 ksq = pos.king_square(Us);
655 if ( file_of(ksq) >= FILE_E
656 && file_of(s) > file_of(ksq)
657 && (relative_rank(Us, ksq) == RANK_1 || rank_of(ksq) == rank_of(s)))
659 // Is there a half-open file between the king and the edge of the board?
660 if (!ei.pi->has_open_file_to_right(Us, file_of(ksq)))
661 score -= make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2
662 : (TrappedRookPenalty - mob * 16), 0);
664 else if ( file_of(ksq) <= FILE_D
665 && file_of(s) < file_of(ksq)
666 && (relative_rank(Us, ksq) == RANK_1 || rank_of(ksq) == rank_of(s)))
668 // Is there a half-open file between the king and the edge of the board?
669 if (!ei.pi->has_open_file_to_left(Us, file_of(ksq)))
670 score -= make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2
671 : (TrappedRookPenalty - mob * 16), 0);
677 TracedScores[Us][Piece] = score;
683 // evaluate_threats<>() assigns bonuses according to the type of attacking piece
684 // and the type of attacked one.
687 Score evaluate_threats(const Position& pos, EvalInfo& ei) {
689 const Color Them = (Us == WHITE ? BLACK : WHITE);
691 Bitboard b, undefendedMinors, weakEnemies;
692 Score score = SCORE_ZERO;
694 // Undefended minors get penalized even if not under attack
695 undefendedMinors = pos.pieces(Them)
696 & (pos.pieces(BISHOP) | pos.pieces(KNIGHT))
697 & ~ei.attackedBy[Them][0];
699 if (undefendedMinors)
700 score += more_than_one(undefendedMinors) ? UndefendedMinorPenalty * 2
701 : UndefendedMinorPenalty;
703 // Enemy pieces not defended by a pawn and under our attack
704 weakEnemies = pos.pieces(Them)
705 & ~ei.attackedBy[Them][PAWN]
706 & ei.attackedBy[Us][0];
711 // Add bonus according to type of attacked enemy piece and to the
712 // type of attacking piece, from knights to queens. Kings are not
713 // considered because are already handled in king evaluation.
714 for (PieceType pt1 = KNIGHT; pt1 < KING; pt1++)
716 b = ei.attackedBy[Us][pt1] & weakEnemies;
718 for (PieceType pt2 = PAWN; pt2 < KING; pt2++)
719 if (b & pos.pieces(pt2))
720 score += ThreatBonus[pt1][pt2];
726 // evaluate_pieces_of_color<>() assigns bonuses and penalties to all the
727 // pieces of a given color.
729 template<Color Us, bool Trace>
730 Score evaluate_pieces_of_color(const Position& pos, EvalInfo& ei, Score& mobility) {
732 const Color Them = (Us == WHITE ? BLACK : WHITE);
734 Score score = mobility = SCORE_ZERO;
736 // Do not include in mobility squares protected by enemy pawns or occupied by our pieces
737 const Bitboard mobilityArea = ~(ei.attackedBy[Them][PAWN] | pos.pieces(Us));
739 score += evaluate_pieces<KNIGHT, Us, Trace>(pos, ei, mobility, mobilityArea);
740 score += evaluate_pieces<BISHOP, Us, Trace>(pos, ei, mobility, mobilityArea);
741 score += evaluate_pieces<ROOK, Us, Trace>(pos, ei, mobility, mobilityArea);
742 score += evaluate_pieces<QUEEN, Us, Trace>(pos, ei, mobility, mobilityArea);
744 // Sum up all attacked squares
745 ei.attackedBy[Us][0] = ei.attackedBy[Us][PAWN] | ei.attackedBy[Us][KNIGHT]
746 | ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK]
747 | ei.attackedBy[Us][QUEEN] | ei.attackedBy[Us][KING];
752 // evaluate_king<>() assigns bonuses and penalties to a king of a given color
754 template<Color Us, bool Trace>
755 Score evaluate_king(const Position& pos, EvalInfo& ei, Value margins[]) {
757 const Color Them = (Us == WHITE ? BLACK : WHITE);
759 Bitboard undefended, b, b1, b2, safe;
761 const Square ksq = pos.king_square(Us);
763 // King shelter and enemy pawns storm
764 Score score = ei.pi->king_safety<Us>(pos, ksq);
766 // King safety. This is quite complicated, and is almost certainly far
767 // from optimally tuned.
768 if ( ei.kingAttackersCount[Them] >= 2
769 && ei.kingAdjacentZoneAttacksCount[Them])
771 // Find the attacked squares around the king which has no defenders
772 // apart from the king itself
773 undefended = ei.attackedBy[Them][0] & ei.attackedBy[Us][KING];
774 undefended &= ~( ei.attackedBy[Us][PAWN] | ei.attackedBy[Us][KNIGHT]
775 | ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK]
776 | ei.attackedBy[Us][QUEEN]);
778 // Initialize the 'attackUnits' variable, which is used later on as an
779 // index to the KingDangerTable[] array. The initial value is based on
780 // the number and types of the enemy's attacking pieces, the number of
781 // attacked and undefended squares around our king, the square of the
782 // king, and the quality of the pawn shelter.
783 attackUnits = std::min(25, (ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) / 2)
784 + 3 * (ei.kingAdjacentZoneAttacksCount[Them] + popcount<Max15>(undefended))
785 + InitKingDanger[relative_square(Us, ksq)]
786 - mg_value(score) / 32;
788 // Analyse enemy's safe queen contact checks. First find undefended
789 // squares around the king attacked by enemy queen...
790 b = undefended & ei.attackedBy[Them][QUEEN] & ~pos.pieces(Them);
793 // ...then remove squares not supported by another enemy piece
794 b &= ( ei.attackedBy[Them][PAWN] | ei.attackedBy[Them][KNIGHT]
795 | ei.attackedBy[Them][BISHOP] | ei.attackedBy[Them][ROOK]);
797 attackUnits += QueenContactCheckBonus
799 * (Them == pos.side_to_move() ? 2 : 1);
802 // Analyse enemy's safe rook contact checks. First find undefended
803 // squares around the king attacked by enemy rooks...
804 b = undefended & ei.attackedBy[Them][ROOK] & ~pos.pieces(Them);
806 // Consider only squares where the enemy rook gives check
807 b &= PseudoAttacks[ROOK][ksq];
811 // ...then remove squares not supported by another enemy piece
812 b &= ( ei.attackedBy[Them][PAWN] | ei.attackedBy[Them][KNIGHT]
813 | ei.attackedBy[Them][BISHOP] | ei.attackedBy[Them][QUEEN]);
815 attackUnits += RookContactCheckBonus
817 * (Them == pos.side_to_move() ? 2 : 1);
820 // Analyse enemy's safe distance checks for sliders and knights
821 safe = ~(pos.pieces(Them) | ei.attackedBy[Us][0]);
823 b1 = pos.attacks_from<ROOK>(ksq) & safe;
824 b2 = pos.attacks_from<BISHOP>(ksq) & safe;
826 // Enemy queen safe checks
827 b = (b1 | b2) & ei.attackedBy[Them][QUEEN];
829 attackUnits += QueenCheckBonus * popcount<Max15>(b);
831 // Enemy rooks safe checks
832 b = b1 & ei.attackedBy[Them][ROOK];
834 attackUnits += RookCheckBonus * popcount<Max15>(b);
836 // Enemy bishops safe checks
837 b = b2 & ei.attackedBy[Them][BISHOP];
839 attackUnits += BishopCheckBonus * popcount<Max15>(b);
841 // Enemy knights safe checks
842 b = pos.attacks_from<KNIGHT>(ksq) & ei.attackedBy[Them][KNIGHT] & safe;
844 attackUnits += KnightCheckBonus * popcount<Max15>(b);
846 // To index KingDangerTable[] attackUnits must be in [0, 99] range
847 attackUnits = std::min(99, std::max(0, attackUnits));
849 // Finally, extract the king danger score from the KingDangerTable[]
850 // array and subtract the score from evaluation. Set also margins[]
851 // value that will be used for pruning because this value can sometimes
852 // be very big, and so capturing a single attacking piece can therefore
853 // result in a score change far bigger than the value of the captured piece.
854 score -= KingDangerTable[Us == Search::RootColor][attackUnits];
855 margins[Us] += mg_value(KingDangerTable[Us == Search::RootColor][attackUnits]);
859 TracedScores[Us][KING] = score;
865 // evaluate_passed_pawns<>() evaluates the passed pawns of the given color
868 Score evaluate_passed_pawns(const Position& pos, EvalInfo& ei) {
870 const Color Them = (Us == WHITE ? BLACK : WHITE);
872 Bitboard b, squaresToQueen, defendedSquares, unsafeSquares, supportingPawns;
873 Score score = SCORE_ZERO;
875 b = ei.pi->passed_pawns(Us);
881 Square s = pop_lsb(&b);
883 assert(pos.pawn_is_passed(Us, s));
885 int r = int(relative_rank(Us, s) - RANK_2);
886 int rr = r * (r - 1);
888 // Base bonus based on rank
889 Value mbonus = Value(20 * rr);
890 Value ebonus = Value(10 * (rr + r + 1));
894 Square blockSq = s + pawn_push(Us);
896 // Adjust bonus based on kings proximity
897 ebonus += Value(square_distance(pos.king_square(Them), blockSq) * 5 * rr);
898 ebonus -= Value(square_distance(pos.king_square(Us), blockSq) * 2 * rr);
900 // If blockSq is not the queening square then consider also a second push
901 if (rank_of(blockSq) != (Us == WHITE ? RANK_8 : RANK_1))
902 ebonus -= Value(square_distance(pos.king_square(Us), blockSq + pawn_push(Us)) * rr);
904 // If the pawn is free to advance, increase bonus
905 if (pos.is_empty(blockSq))
907 squaresToQueen = forward_bb(Us, s);
908 defendedSquares = squaresToQueen & ei.attackedBy[Us][0];
910 // If there is an enemy rook or queen attacking the pawn from behind,
911 // add all X-ray attacks by the rook or queen. Otherwise consider only
912 // the squares in the pawn's path attacked or occupied by the enemy.
913 if ( (forward_bb(Them, s) & pos.pieces(Them, ROOK, QUEEN))
914 && (forward_bb(Them, s) & pos.pieces(Them, ROOK, QUEEN) & pos.attacks_from<ROOK>(s)))
915 unsafeSquares = squaresToQueen;
917 unsafeSquares = squaresToQueen & (ei.attackedBy[Them][0] | pos.pieces(Them));
919 // If there aren't enemy attacks or pieces along the path to queen give
920 // huge bonus. Even bigger if we protect the pawn's path.
922 ebonus += Value(rr * (squaresToQueen == defendedSquares ? 17 : 15));
924 // OK, there are enemy attacks or pieces (but not pawns). Are those
925 // squares which are attacked by the enemy also attacked by us ?
926 // If yes, big bonus (but smaller than when there are no enemy attacks),
927 // if no, somewhat smaller bonus.
928 ebonus += Value(rr * ((unsafeSquares & defendedSquares) == unsafeSquares ? 13 : 8));
932 // Increase the bonus if the passed pawn is supported by a friendly pawn
933 // on the same rank and a bit smaller if it's on the previous rank.
934 supportingPawns = pos.pieces(Us, PAWN) & adjacent_files_bb(file_of(s));
935 if (supportingPawns & rank_bb(s))
936 ebonus += Value(r * 20);
938 else if (supportingPawns & rank_bb(s - pawn_push(Us)))
939 ebonus += Value(r * 12);
941 // Rook pawns are a special case: They are sometimes worse, and
942 // sometimes better than other passed pawns. It is difficult to find
943 // good rules for determining whether they are good or bad. For now,
944 // we try the following: Increase the value for rook pawns if the
945 // other side has no pieces apart from a knight, and decrease the
946 // value if the other side has a rook or queen.
947 if (file_of(s) == FILE_A || file_of(s) == FILE_H)
949 if (pos.non_pawn_material(Them) <= KnightValueMg)
950 ebonus += ebonus / 4;
951 else if (pos.pieces(Them, ROOK, QUEEN))
952 ebonus -= ebonus / 4;
954 score += make_score(mbonus, ebonus);
958 // Add the scores to the middle game and endgame eval
959 return apply_weight(score, Weights[PassedPawns]);
963 // evaluate_unstoppable_pawns() evaluates the unstoppable passed pawns for both sides, this is quite
964 // conservative and returns a winning score only when we are very sure that the pawn is winning.
966 Score evaluate_unstoppable_pawns(const Position& pos, EvalInfo& ei) {
968 Bitboard b, b2, blockers, supporters, queeningPath, candidates;
969 Square s, blockSq, queeningSquare;
970 Color c, winnerSide, loserSide;
971 bool pathDefended, opposed;
972 int pliesToGo, movesToGo, oppMovesToGo, sacptg, blockersCount, minKingDist, kingptg, d;
973 int pliesToQueen[] = { 256, 256 };
975 // Step 1. Hunt for unstoppable passed pawns. If we find at least one,
976 // record how many plies are required for promotion.
977 for (c = WHITE; c <= BLACK; c++)
979 // Skip if other side has non-pawn pieces
980 if (pos.non_pawn_material(~c))
983 b = ei.pi->passed_pawns(c);
988 queeningSquare = relative_square(c, file_of(s) | RANK_8);
989 queeningPath = forward_bb(c, s);
991 // Compute plies to queening and check direct advancement
992 movesToGo = rank_distance(s, queeningSquare) - int(relative_rank(c, s) == RANK_2);
993 oppMovesToGo = square_distance(pos.king_square(~c), queeningSquare) - int(c != pos.side_to_move());
994 pathDefended = ((ei.attackedBy[c][0] & queeningPath) == queeningPath);
996 if (movesToGo >= oppMovesToGo && !pathDefended)
999 // Opponent king cannot block because path is defended and position
1000 // is not in check. So only friendly pieces can be blockers.
1001 assert(!pos.in_check());
1002 assert((queeningPath & pos.pieces()) == (queeningPath & pos.pieces(c)));
1004 // Add moves needed to free the path from friendly pieces and retest condition
1005 movesToGo += popcount<Max15>(queeningPath & pos.pieces(c));
1007 if (movesToGo >= oppMovesToGo && !pathDefended)
1010 pliesToGo = 2 * movesToGo - int(c == pos.side_to_move());
1011 pliesToQueen[c] = std::min(pliesToQueen[c], pliesToGo);
1015 // Step 2. If either side cannot promote at least three plies before the other side then situation
1016 // becomes too complex and we give up. Otherwise we determine the possibly "winning side"
1017 if (abs(pliesToQueen[WHITE] - pliesToQueen[BLACK]) < 3)
1020 winnerSide = (pliesToQueen[WHITE] < pliesToQueen[BLACK] ? WHITE : BLACK);
1021 loserSide = ~winnerSide;
1023 // Step 3. Can the losing side possibly create a new passed pawn and thus prevent the loss?
1024 b = candidates = pos.pieces(loserSide, PAWN);
1030 // Compute plies from queening
1031 queeningSquare = relative_square(loserSide, file_of(s) | RANK_8);
1032 movesToGo = rank_distance(s, queeningSquare) - int(relative_rank(loserSide, s) == RANK_2);
1033 pliesToGo = 2 * movesToGo - int(loserSide == pos.side_to_move());
1035 // Check if (without even considering any obstacles) we're too far away or doubled
1036 if ( pliesToQueen[winnerSide] + 3 <= pliesToGo
1037 || (forward_bb(loserSide, s) & pos.pieces(loserSide, PAWN)))
1041 // If any candidate is already a passed pawn it _may_ promote in time. We give up.
1042 if (candidates & ei.pi->passed_pawns(loserSide))
1045 // Step 4. Check new passed pawn creation through king capturing and pawn sacrifices
1051 sacptg = blockersCount = 0;
1052 minKingDist = kingptg = 256;
1054 // Compute plies from queening
1055 queeningSquare = relative_square(loserSide, file_of(s) | RANK_8);
1056 movesToGo = rank_distance(s, queeningSquare) - int(relative_rank(loserSide, s) == RANK_2);
1057 pliesToGo = 2 * movesToGo - int(loserSide == pos.side_to_move());
1059 // Generate list of blocking pawns and supporters
1060 supporters = adjacent_files_bb(file_of(s)) & candidates;
1061 opposed = forward_bb(loserSide, s) & pos.pieces(winnerSide, PAWN);
1062 blockers = passed_pawn_mask(loserSide, s) & pos.pieces(winnerSide, PAWN);
1066 // How many plies does it take to remove all the blocking pawns?
1069 blockSq = pop_lsb(&blockers);
1072 // Check pawns that can give support to overcome obstacle, for instance
1073 // black pawns: a4, b4 white: b2 then pawn in b4 is giving support.
1076 b2 = supporters & in_front_bb(winnerSide, blockSq + pawn_push(winnerSide));
1078 while (b2) // This while-loop could be replaced with LSB/MSB (depending on color)
1080 d = square_distance(blockSq, pop_lsb(&b2)) - 2;
1081 movesToGo = std::min(movesToGo, d);
1085 // Check pawns that can be sacrificed against the blocking pawn
1086 b2 = attack_span_mask(winnerSide, blockSq) & candidates & ~(1ULL << s);
1088 while (b2) // This while-loop could be replaced with LSB/MSB (depending on color)
1090 d = square_distance(blockSq, pop_lsb(&b2)) - 2;
1091 movesToGo = std::min(movesToGo, d);
1094 // If obstacle can be destroyed with an immediate pawn exchange / sacrifice,
1095 // it's not a real obstacle and we have nothing to add to pliesToGo.
1099 // Plies needed to sacrifice against all the blocking pawns
1100 sacptg += movesToGo * 2;
1103 // Plies needed for the king to capture all the blocking pawns
1104 d = square_distance(pos.king_square(loserSide), blockSq);
1105 minKingDist = std::min(minKingDist, d);
1106 kingptg = (minKingDist + blockersCount) * 2;
1109 // Check if pawn sacrifice plan _may_ save the day
1110 if (pliesToQueen[winnerSide] + 3 > pliesToGo + sacptg)
1113 // Check if king capture plan _may_ save the day (contains some false positives)
1114 if (pliesToQueen[winnerSide] + 3 > pliesToGo + kingptg)
1118 // Winning pawn is unstoppable and will promote as first, return big score
1119 Score score = make_score(0, (Value) 1280 - 32 * pliesToQueen[winnerSide]);
1120 return winnerSide == WHITE ? score : -score;
1124 // evaluate_space() computes the space evaluation for a given side. The
1125 // space evaluation is a simple bonus based on the number of safe squares
1126 // available for minor pieces on the central four files on ranks 2--4. Safe
1127 // squares one, two or three squares behind a friendly pawn are counted
1128 // twice. Finally, the space bonus is scaled by a weight taken from the
1129 // material hash table. The aim is to improve play on game opening.
1131 int evaluate_space(const Position& pos, EvalInfo& ei) {
1133 const Color Them = (Us == WHITE ? BLACK : WHITE);
1135 // Find the safe squares for our pieces inside the area defined by
1136 // SpaceMask[]. A square is unsafe if it is attacked by an enemy
1137 // pawn, or if it is undefended and attacked by an enemy piece.
1138 Bitboard safe = SpaceMask[Us]
1139 & ~pos.pieces(Us, PAWN)
1140 & ~ei.attackedBy[Them][PAWN]
1141 & (ei.attackedBy[Us][0] | ~ei.attackedBy[Them][0]);
1143 // Find all squares which are at most three squares behind some friendly pawn
1144 Bitboard behind = pos.pieces(Us, PAWN);
1145 behind |= (Us == WHITE ? behind >> 8 : behind << 8);
1146 behind |= (Us == WHITE ? behind >> 16 : behind << 16);
1148 return popcount<Max15>(safe) + popcount<Max15>(behind & safe);
1152 // interpolate() interpolates between a middle game and an endgame score,
1153 // based on game phase. It also scales the return value by a ScaleFactor array.
1155 Value interpolate(const Score& v, Phase ph, ScaleFactor sf) {
1157 assert(mg_value(v) > -VALUE_INFINITE && mg_value(v) < VALUE_INFINITE);
1158 assert(eg_value(v) > -VALUE_INFINITE && eg_value(v) < VALUE_INFINITE);
1159 assert(ph >= PHASE_ENDGAME && ph <= PHASE_MIDGAME);
1161 int ev = (eg_value(v) * int(sf)) / SCALE_FACTOR_NORMAL;
1162 int result = (mg_value(v) * int(ph) + ev * int(128 - ph)) / 128;
1163 return Value((result + GrainSize / 2) & ~(GrainSize - 1));
1167 // weight_option() computes the value of an evaluation weight, by combining
1168 // two UCI-configurable weights (midgame and endgame) with an internal weight.
1170 Score weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight) {
1172 // Scale option value from 100 to 256
1173 int mg = Options[mgOpt] * 256 / 100;
1174 int eg = Options[egOpt] * 256 / 100;
1176 return apply_weight(make_score(mg, eg), internalWeight);
1180 // A couple of little helpers used by tracing code, to_cp() converts a value to
1181 // a double in centipawns scale, trace_add() stores white and black scores.
1183 double to_cp(Value v) { return double(v) / double(PawnValueMg); }
1185 void trace_add(int idx, Score wScore, Score bScore) {
1187 TracedScores[WHITE][idx] = wScore;
1188 TracedScores[BLACK][idx] = bScore;
1192 // trace_row() is an helper function used by tracing code to register the
1193 // values of a single evaluation term.
1195 void trace_row(const char* name, int idx) {
1197 Score wScore = TracedScores[WHITE][idx];
1198 Score bScore = TracedScores[BLACK][idx];
1201 case PST: case IMBALANCE: case PAWN: case UNSTOPPABLE: case TOTAL:
1202 TraceStream << std::setw(20) << name << " | --- --- | --- --- | "
1203 << std::setw(6) << to_cp(mg_value(wScore)) << " "
1204 << std::setw(6) << to_cp(eg_value(wScore)) << " \n";
1207 TraceStream << std::setw(20) << name << " | " << std::noshowpos
1208 << std::setw(5) << to_cp(mg_value(wScore)) << " "
1209 << std::setw(5) << to_cp(eg_value(wScore)) << " | "
1210 << std::setw(5) << to_cp(mg_value(bScore)) << " "
1211 << std::setw(5) << to_cp(eg_value(bScore)) << " | "
1213 << std::setw(6) << to_cp(mg_value(wScore - bScore)) << " "
1214 << std::setw(6) << to_cp(eg_value(wScore - bScore)) << " \n";