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 };
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)
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 // CLOP now likes 85, 31 - try next
154 const Score BishopPinBonus = make_score(34, 17);
156 // Bonus for having the side to move (modified by Joona Kiiski)
157 const Score Tempo = make_score(24, 11);
159 // Rooks and queens on the 7th rank
160 const Score RookOn7thBonus = make_score(3, 20);
161 const Score QueenOn7thBonus = make_score(1, 8);
163 // Rooks and queens attacking pawns on the same rank
164 const Score RookOnPawnBonus = make_score(3, 48);
165 const Score QueenOnPawnBonus = make_score(1, 40);
167 // Rooks on open files (modified by Joona Kiiski)
168 const Score RookOpenFileBonus = make_score(43, 21);
169 const Score RookHalfOpenFileBonus = make_score(19, 10);
171 // Penalty for rooks trapped inside a friendly king which has lost the
173 const Value TrappedRookPenalty = Value(180);
175 // Penalty for a bishop on a1/h1 (a8/h8 for black) which is trapped by
176 // a friendly pawn on b2/g2 (b7/g7 for black). This can obviously only
177 // happen in Chess960 games.
178 const Score TrappedBishopA1H1Penalty = make_score(100, 100);
180 // Penalty for an undefended bishop or knight
181 const Score UndefendedMinorPenalty = make_score(25, 10);
183 // The SpaceMask[Color] contains the area of the board which is considered
184 // by the space evaluation. In the middle game, each side is given a bonus
185 // based on how many squares inside this area are safe and available for
186 // friendly minor pieces.
187 const Bitboard SpaceMask[] = {
188 (1ULL << SQ_C2) | (1ULL << SQ_D2) | (1ULL << SQ_E2) | (1ULL << SQ_F2) |
189 (1ULL << SQ_C3) | (1ULL << SQ_D3) | (1ULL << SQ_E3) | (1ULL << SQ_F3) |
190 (1ULL << SQ_C4) | (1ULL << SQ_D4) | (1ULL << SQ_E4) | (1ULL << SQ_F4),
191 (1ULL << SQ_C7) | (1ULL << SQ_D7) | (1ULL << SQ_E7) | (1ULL << SQ_F7) |
192 (1ULL << SQ_C6) | (1ULL << SQ_D6) | (1ULL << SQ_E6) | (1ULL << SQ_F6) |
193 (1ULL << SQ_C5) | (1ULL << SQ_D5) | (1ULL << SQ_E5) | (1ULL << SQ_F5)
196 // King danger constants and variables. The king danger scores are taken
197 // from the KingDangerTable[]. Various little "meta-bonuses" measuring
198 // the strength of the enemy attack are added up into an integer, which
199 // is used as an index to KingDangerTable[].
201 // King safety evaluation is asymmetrical and different for us (root color)
202 // and for our opponent. These values are used to init KingDangerTable.
203 const int KingDangerWeights[] = { 259, 247 };
205 // KingAttackWeights[PieceType] contains king attack weights by piece type
206 const int KingAttackWeights[] = { 0, 0, 2, 2, 3, 5 };
208 // Bonuses for enemy's safe checks
209 const int QueenContactCheckBonus = 6;
210 const int RookContactCheckBonus = 4;
211 const int QueenCheckBonus = 3;
212 const int RookCheckBonus = 2;
213 const int BishopCheckBonus = 1;
214 const int KnightCheckBonus = 1;
216 // InitKingDanger[Square] contains penalties based on the position of the
217 // defending king, indexed by king's square (from white's point of view).
218 const int InitKingDanger[] = {
219 2, 0, 2, 5, 5, 2, 0, 2,
220 2, 2, 4, 8, 8, 4, 2, 2,
221 7, 10, 12, 12, 12, 12, 10, 7,
222 15, 15, 15, 15, 15, 15, 15, 15,
223 15, 15, 15, 15, 15, 15, 15, 15,
224 15, 15, 15, 15, 15, 15, 15, 15,
225 15, 15, 15, 15, 15, 15, 15, 15,
226 15, 15, 15, 15, 15, 15, 15, 15
229 // KingDangerTable[Color][attackUnits] contains the actual king danger
230 // weighted scores, indexed by color and by a calculated integer number.
231 Score KingDangerTable[COLOR_NB][128];
233 // TracedTerms[Color][PieceType || TracedType] contains a breakdown of the
234 // evaluation terms, used when tracing.
235 Score TracedScores[COLOR_NB][16];
236 std::stringstream TraceStream;
239 PST = 8, IMBALANCE = 9, MOBILITY = 10, THREAT = 11,
240 PASSED = 12, UNSTOPPABLE = 13, SPACE = 14, TOTAL = 15
243 // Function prototypes
245 Value do_evaluate(const Position& pos, Value& margin);
248 void init_eval_info(const Position& pos, EvalInfo& ei);
250 template<Color Us, bool Trace>
251 Score evaluate_pieces_of_color(const Position& pos, EvalInfo& ei, Score& mobility);
253 template<Color Us, bool Trace>
254 Score evaluate_king(const Position& pos, EvalInfo& ei, Value margins[]);
257 Score evaluate_threats(const Position& pos, EvalInfo& ei);
260 int evaluate_space(const Position& pos, EvalInfo& ei);
263 Score evaluate_passed_pawns(const Position& pos, EvalInfo& ei);
265 Score evaluate_unstoppable_pawns(const Position& pos, EvalInfo& ei);
267 Value interpolate(const Score& v, Phase ph, ScaleFactor sf);
268 Score weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight);
269 double to_cp(Value v);
270 void trace_add(int idx, Score term_w, Score term_b = SCORE_ZERO);
271 void trace_row(const char* name, int idx);
277 /// evaluate() is the main evaluation function. It always computes two
278 /// values, an endgame score and a middle game score, and interpolates
279 /// between them based on the remaining material.
281 Value evaluate(const Position& pos, Value& margin) {
282 return do_evaluate<false>(pos, margin);
286 /// init() computes evaluation weights from the corresponding UCI parameters
287 /// and setup king tables.
291 Weights[Mobility] = weight_option("Mobility (Middle Game)", "Mobility (Endgame)", WeightsInternal[Mobility]);
292 Weights[PassedPawns] = weight_option("Passed Pawns (Middle Game)", "Passed Pawns (Endgame)", WeightsInternal[PassedPawns]);
293 Weights[Space] = weight_option("Space", "Space", WeightsInternal[Space]);
295 int KingDanger[] = { KingDangerWeights[0], KingDangerWeights[1] };
297 // If running in analysis mode, make sure we use symmetrical king safety.
298 // We do so by replacing both KingDanger weights by their average.
299 if (Options["UCI_AnalyseMode"])
300 KingDanger[0] = KingDanger[1] = (KingDanger[0] + KingDanger[1]) / 2;
302 const int MaxSlope = 30;
303 const int Peak = 1280;
305 for (int t = 0, i = 1; i < 100; i++)
307 t = std::min(Peak, std::min(int(0.4 * i * i), t + MaxSlope));
309 KingDangerTable[0][i] = apply_weight(make_score(t, 0), make_score(KingDanger[0], 0));
310 KingDangerTable[1][i] = apply_weight(make_score(t, 0), make_score(KingDanger[1], 0));
315 /// trace() is like evaluate() but instead of a value returns a string suitable
316 /// to be print on stdout with the detailed descriptions and values of each
317 /// evaluation term. Used mainly for debugging.
319 std::string trace(const Position& pos) {
324 Search::RootColor = pos.side_to_move();
327 TraceStream << std::showpoint << std::showpos << std::fixed << std::setprecision(2);
328 memset(TracedScores, 0, 2 * 16 * sizeof(Score));
330 do_evaluate<true>(pos, margin);
332 totals = TraceStream.str();
335 TraceStream << std::setw(21) << "Eval term " << "| White | Black | Total \n"
336 << " | MG EG | MG EG | MG EG \n"
337 << "---------------------+-------------+-------------+---------------\n";
339 trace_row("Material, PST, Tempo", PST);
340 trace_row("Material imbalance", IMBALANCE);
341 trace_row("Pawns", PAWN);
342 trace_row("Knights", KNIGHT);
343 trace_row("Bishops", BISHOP);
344 trace_row("Rooks", ROOK);
345 trace_row("Queens", QUEEN);
346 trace_row("Mobility", MOBILITY);
347 trace_row("King safety", KING);
348 trace_row("Threats", THREAT);
349 trace_row("Passed pawns", PASSED);
350 trace_row("Unstoppable pawns", UNSTOPPABLE);
351 trace_row("Space", SPACE);
353 TraceStream << "---------------------+-------------+-------------+---------------\n";
354 trace_row("Total", TOTAL);
355 TraceStream << totals;
357 return TraceStream.str();
366 Value do_evaluate(const Position& pos, Value& margin) {
368 assert(!pos.checkers());
371 Value margins[COLOR_NB];
372 Score score, mobilityWhite, mobilityBlack;
373 Thread* th = pos.this_thread();
375 // margins[] store the uncertainty estimation of position's evaluation
376 // that typically is used by the search for pruning decisions.
377 margins[WHITE] = margins[BLACK] = VALUE_ZERO;
379 // Initialize score by reading the incrementally updated scores included
380 // in the position object (material + piece square tables) and adding
381 // Tempo bonus. Score is computed from the point of view of white.
382 score = pos.psq_score() + (pos.side_to_move() == WHITE ? Tempo : -Tempo);
384 // Probe the material hash table
385 ei.mi = Material::probe(pos, th->materialTable, th->endgames);
386 score += ei.mi->material_value();
388 // If we have a specialized evaluation function for the current material
389 // configuration, call it and return.
390 if (ei.mi->specialized_eval_exists())
393 return ei.mi->evaluate(pos);
396 // Probe the pawn hash table
397 ei.pi = Pawns::probe(pos, th->pawnsTable);
398 score += ei.pi->pawns_value();
400 // Initialize attack and king safety bitboards
401 init_eval_info<WHITE>(pos, ei);
402 init_eval_info<BLACK>(pos, ei);
404 // Evaluate pieces and mobility
405 score += evaluate_pieces_of_color<WHITE, Trace>(pos, ei, mobilityWhite)
406 - evaluate_pieces_of_color<BLACK, Trace>(pos, ei, mobilityBlack);
408 score += apply_weight(mobilityWhite - mobilityBlack, Weights[Mobility]);
410 // Evaluate kings after all other pieces because we need complete attack
411 // information when computing the king safety evaluation.
412 score += evaluate_king<WHITE, Trace>(pos, ei, margins)
413 - evaluate_king<BLACK, Trace>(pos, ei, margins);
415 // Evaluate tactical threats, we need full attack information including king
416 score += evaluate_threats<WHITE>(pos, ei)
417 - evaluate_threats<BLACK>(pos, ei);
419 // Evaluate passed pawns, we need full attack information including king
420 score += evaluate_passed_pawns<WHITE>(pos, ei)
421 - evaluate_passed_pawns<BLACK>(pos, ei);
423 // If one side has only a king, check whether exists any unstoppable passed pawn
424 if (!pos.non_pawn_material(WHITE) || !pos.non_pawn_material(BLACK))
425 score += evaluate_unstoppable_pawns(pos, ei);
427 // Evaluate space for both sides, only in middle-game.
428 if (ei.mi->space_weight())
430 int s = evaluate_space<WHITE>(pos, ei) - evaluate_space<BLACK>(pos, ei);
431 score += apply_weight(make_score(s * ei.mi->space_weight(), 0), Weights[Space]);
434 // Scale winning side if position is more drawish that what it appears
435 ScaleFactor sf = eg_value(score) > VALUE_DRAW ? ei.mi->scale_factor(pos, WHITE)
436 : ei.mi->scale_factor(pos, BLACK);
438 // If we don't already have an unusual scale factor, check for opposite
439 // colored bishop endgames, and use a lower scale for those.
440 if ( ei.mi->game_phase() < PHASE_MIDGAME
441 && pos.opposite_bishops()
442 && sf == SCALE_FACTOR_NORMAL)
444 // Only the two bishops ?
445 if ( pos.non_pawn_material(WHITE) == BishopValueMg
446 && pos.non_pawn_material(BLACK) == BishopValueMg)
448 // Check for KBP vs KB with only a single pawn that is almost
449 // certainly a draw or at least two pawns.
450 bool one_pawn = (pos.piece_count(WHITE, PAWN) + pos.piece_count(BLACK, PAWN) == 1);
451 sf = one_pawn ? ScaleFactor(8) : ScaleFactor(32);
454 // Endgame with opposite-colored bishops, but also other pieces. Still
455 // a bit drawish, but not as drawish as with only the two bishops.
456 sf = ScaleFactor(50);
459 margin = margins[pos.side_to_move()];
460 Value v = interpolate(score, ei.mi->game_phase(), sf);
462 // In case of tracing add all single evaluation contributions for both white and black
465 trace_add(PST, pos.psq_score());
466 trace_add(IMBALANCE, ei.mi->material_value());
467 trace_add(PAWN, ei.pi->pawns_value());
468 trace_add(MOBILITY, apply_weight(mobilityWhite, Weights[Mobility]), apply_weight(mobilityBlack, Weights[Mobility]));
469 trace_add(THREAT, evaluate_threats<WHITE>(pos, ei), evaluate_threats<BLACK>(pos, ei));
470 trace_add(PASSED, evaluate_passed_pawns<WHITE>(pos, ei), evaluate_passed_pawns<BLACK>(pos, ei));
471 trace_add(UNSTOPPABLE, evaluate_unstoppable_pawns(pos, ei));
472 Score w = make_score(ei.mi->space_weight() * evaluate_space<WHITE>(pos, ei), 0);
473 Score b = make_score(ei.mi->space_weight() * evaluate_space<BLACK>(pos, ei), 0);
474 trace_add(SPACE, apply_weight(w, Weights[Space]), apply_weight(b, Weights[Space]));
475 trace_add(TOTAL, score);
476 TraceStream << "\nUncertainty margin: White: " << to_cp(margins[WHITE])
477 << ", Black: " << to_cp(margins[BLACK])
478 << "\nScaling: " << std::noshowpos
479 << std::setw(6) << 100.0 * ei.mi->game_phase() / 128.0 << "% MG, "
480 << std::setw(6) << 100.0 * (1.0 - ei.mi->game_phase() / 128.0) << "% * "
481 << std::setw(6) << (100.0 * sf) / SCALE_FACTOR_NORMAL << "% EG.\n"
482 << "Total evaluation: " << to_cp(v);
485 return pos.side_to_move() == WHITE ? v : -v;
489 // init_eval_info() initializes king bitboards for given color adding
490 // pawn attacks. To be done at the beginning of the evaluation.
493 void init_eval_info(const Position& pos, EvalInfo& ei) {
495 const Color Them = (Us == WHITE ? BLACK : WHITE);
497 Bitboard b = ei.attackedBy[Them][KING] = pos.attacks_from<KING>(pos.king_square(Them));
498 ei.attackedBy[Us][PAWN] = ei.pi->pawn_attacks(Us);
500 // Init king safety tables only if we are going to use them
501 if ( pos.piece_count(Us, QUEEN)
502 && pos.non_pawn_material(Us) >= QueenValueMg + RookValueMg)
504 ei.kingRing[Them] = (b | (Us == WHITE ? b >> 8 : b << 8));
505 b &= ei.attackedBy[Us][PAWN];
506 ei.kingAttackersCount[Us] = b ? popcount<Max15>(b) / 2 : 0;
507 ei.kingAdjacentZoneAttacksCount[Us] = ei.kingAttackersWeight[Us] = 0;
509 ei.kingRing[Them] = ei.kingAttackersCount[Us] = 0;
513 // evaluate_outposts() evaluates bishop and knight outposts squares
515 template<PieceType Piece, Color Us>
516 Score evaluate_outposts(const Position& pos, EvalInfo& ei, Square s) {
518 const Color Them = (Us == WHITE ? BLACK : WHITE);
520 assert (Piece == BISHOP || Piece == KNIGHT);
522 // Initial bonus based on square
523 Value bonus = OutpostBonus[Piece == BISHOP][relative_square(Us, s)];
525 // Increase bonus if supported by pawn, especially if the opponent has
526 // no minor piece which can exchange the outpost piece.
527 if (bonus && (ei.attackedBy[Us][PAWN] & s))
529 if ( !pos.pieces(Them, KNIGHT)
530 && !(same_color_squares(s) & pos.pieces(Them, BISHOP)))
531 bonus += bonus + bonus / 2;
535 return make_score(bonus, bonus);
539 // evaluate_pieces<>() assigns bonuses and penalties to the pieces of a given color
541 template<PieceType Piece, Color Us, bool Trace>
542 Score evaluate_pieces(const Position& pos, EvalInfo& ei, Score& mobility, Bitboard mobilityArea) {
548 Score score = SCORE_ZERO;
550 const Color Them = (Us == WHITE ? BLACK : WHITE);
551 const Square* pl = pos.piece_list(Us, Piece);
553 ei.attackedBy[Us][Piece] = 0;
555 while ((s = *pl++) != SQ_NONE)
557 // Find attacked squares, including x-ray attacks for bishops and rooks
558 if (Piece == KNIGHT || Piece == QUEEN)
559 b = pos.attacks_from<Piece>(s);
560 else if (Piece == BISHOP)
561 b = attacks_bb<BISHOP>(s, pos.pieces() ^ pos.pieces(Us, QUEEN));
562 else if (Piece == ROOK)
563 b = attacks_bb<ROOK>(s, pos.pieces() ^ pos.pieces(Us, ROOK, QUEEN));
567 ei.attackedBy[Us][Piece] |= b;
569 if (b & ei.kingRing[Them])
571 ei.kingAttackersCount[Us]++;
572 ei.kingAttackersWeight[Us] += KingAttackWeights[Piece];
573 Bitboard bb = (b & ei.attackedBy[Them][KING]);
575 ei.kingAdjacentZoneAttacksCount[Us] += popcount<Max15>(bb);
578 mob = (Piece != QUEEN ? popcount<Max15>(b & mobilityArea)
579 : popcount<Full >(b & mobilityArea));
581 mobility += MobilityBonus[Piece][mob];
583 // Decrease score if we are attacked by an enemy pawn. Remaining part
584 // of threat evaluation must be done later when we have full attack info.
585 if (ei.attackedBy[Them][PAWN] & s)
586 score -= ThreatenedByPawnPenalty[Piece];
587 else if (Piece == BISHOP && (PseudoAttacks[Piece][pos.king_square(Them)] & s)) {
588 const Bitboard between = BetweenBB[s][pos.king_square(Them)] & pos.pieces();
589 if (!more_than_one(between))
590 score += BishopPinBonus;
593 // Bishop and knight outposts squares
594 if ( (Piece == BISHOP || Piece == KNIGHT)
595 && !(pos.pieces(Them, PAWN) & attack_span_mask(Us, s)))
596 score += evaluate_outposts<Piece, Us>(pos, ei, s);
598 if ((Piece == ROOK || Piece == QUEEN) && relative_rank(Us, s) >= RANK_5)
600 // Major piece on 7th rank
601 if ( relative_rank(Us, s) == RANK_7
602 && relative_rank(Us, pos.king_square(Them)) == RANK_8)
603 score += (Piece == ROOK ? RookOn7thBonus : QueenOn7thBonus);
605 // Major piece attacking pawns on the same rank
606 Bitboard pawns = pos.pieces(Them, PAWN) & rank_bb(s);
608 score += (Piece == ROOK ? RookOnPawnBonus
609 : QueenOnPawnBonus) * popcount<Max15>(pawns);
612 // Special extra evaluation for bishops
613 if (Piece == BISHOP && pos.is_chess960())
615 // An important Chess960 pattern: A cornered bishop blocked by
616 // a friendly pawn diagonally in front of it is a very serious
617 // problem, especially when that pawn is also blocked.
618 if (s == relative_square(Us, SQ_A1) || s == relative_square(Us, SQ_H1))
620 Square d = pawn_push(Us) + (file_of(s) == FILE_A ? DELTA_E : DELTA_W);
621 if (pos.piece_on(s + d) == make_piece(Us, PAWN))
623 if (!pos.is_empty(s + d + pawn_push(Us)))
624 score -= 2*TrappedBishopA1H1Penalty;
625 else if (pos.piece_on(s + 2*d) == make_piece(Us, PAWN))
626 score -= TrappedBishopA1H1Penalty;
628 score -= TrappedBishopA1H1Penalty / 2;
633 // Special extra evaluation for rooks
636 // Open and half-open files
638 if (ei.pi->file_is_half_open(Us, f))
640 if (ei.pi->file_is_half_open(Them, f))
641 score += RookOpenFileBonus;
643 score += RookHalfOpenFileBonus;
646 // Penalize rooks which are trapped inside a king. Penalize more if
647 // king has lost right to castle.
648 if (mob > 6 || ei.pi->file_is_half_open(Us, f))
651 ksq = pos.king_square(Us);
653 if ( file_of(ksq) >= FILE_E
654 && file_of(s) > file_of(ksq)
655 && (relative_rank(Us, ksq) == RANK_1 || rank_of(ksq) == rank_of(s)))
657 // Is there a half-open file between the king and the edge of the board?
658 if (!ei.pi->has_open_file_to_right(Us, file_of(ksq)))
659 score -= make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2
660 : (TrappedRookPenalty - mob * 16), 0);
662 else if ( file_of(ksq) <= FILE_D
663 && file_of(s) < file_of(ksq)
664 && (relative_rank(Us, ksq) == RANK_1 || rank_of(ksq) == rank_of(s)))
666 // Is there a half-open file between the king and the edge of the board?
667 if (!ei.pi->has_open_file_to_left(Us, file_of(ksq)))
668 score -= make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2
669 : (TrappedRookPenalty - mob * 16), 0);
675 TracedScores[Us][Piece] = score;
681 // evaluate_threats<>() assigns bonuses according to the type of attacking piece
682 // and the type of attacked one.
685 Score evaluate_threats(const Position& pos, EvalInfo& ei) {
687 const Color Them = (Us == WHITE ? BLACK : WHITE);
689 Bitboard b, undefendedMinors, weakEnemies;
690 Score score = SCORE_ZERO;
692 // Undefended minors get penalized even if not under attack
693 undefendedMinors = pos.pieces(Them)
694 & (pos.pieces(BISHOP) | pos.pieces(KNIGHT))
695 & ~ei.attackedBy[Them][0];
697 if (undefendedMinors)
698 score += UndefendedMinorPenalty;
700 // Enemy pieces not defended by a pawn and under our attack
701 weakEnemies = pos.pieces(Them)
702 & ~ei.attackedBy[Them][PAWN]
703 & ei.attackedBy[Us][0];
708 // Add bonus according to type of attacked enemy piece and to the
709 // type of attacking piece, from knights to queens. Kings are not
710 // considered because are already handled in king evaluation.
711 for (PieceType pt1 = KNIGHT; pt1 < KING; pt1++)
713 b = ei.attackedBy[Us][pt1] & weakEnemies;
715 for (PieceType pt2 = PAWN; pt2 < KING; pt2++)
716 if (b & pos.pieces(pt2))
717 score += ThreatBonus[pt1][pt2];
723 // evaluate_pieces_of_color<>() assigns bonuses and penalties to all the
724 // pieces of a given color.
726 template<Color Us, bool Trace>
727 Score evaluate_pieces_of_color(const Position& pos, EvalInfo& ei, Score& mobility) {
729 const Color Them = (Us == WHITE ? BLACK : WHITE);
731 Score score = mobility = SCORE_ZERO;
733 // Do not include in mobility squares protected by enemy pawns or occupied by our pieces
734 const Bitboard mobilityArea = ~(ei.attackedBy[Them][PAWN] | pos.pieces(Us));
736 score += evaluate_pieces<KNIGHT, Us, Trace>(pos, ei, mobility, mobilityArea);
737 score += evaluate_pieces<BISHOP, Us, Trace>(pos, ei, mobility, mobilityArea);
738 score += evaluate_pieces<ROOK, Us, Trace>(pos, ei, mobility, mobilityArea);
739 score += evaluate_pieces<QUEEN, Us, Trace>(pos, ei, mobility, mobilityArea);
741 // Sum up all attacked squares
742 ei.attackedBy[Us][0] = ei.attackedBy[Us][PAWN] | ei.attackedBy[Us][KNIGHT]
743 | ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK]
744 | ei.attackedBy[Us][QUEEN] | ei.attackedBy[Us][KING];
749 // evaluate_king<>() assigns bonuses and penalties to a king of a given color
751 template<Color Us, bool Trace>
752 Score evaluate_king(const Position& pos, EvalInfo& ei, Value margins[]) {
754 const Color Them = (Us == WHITE ? BLACK : WHITE);
756 Bitboard undefended, b, b1, b2, safe;
758 const Square ksq = pos.king_square(Us);
760 // King shelter and enemy pawns storm
761 Score score = ei.pi->king_safety<Us>(pos, ksq);
763 // King safety. This is quite complicated, and is almost certainly far
764 // from optimally tuned.
765 if ( ei.kingAttackersCount[Them] >= 2
766 && ei.kingAdjacentZoneAttacksCount[Them])
768 // Find the attacked squares around the king which has no defenders
769 // apart from the king itself
770 undefended = ei.attackedBy[Them][0] & ei.attackedBy[Us][KING];
771 undefended &= ~( ei.attackedBy[Us][PAWN] | ei.attackedBy[Us][KNIGHT]
772 | ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK]
773 | ei.attackedBy[Us][QUEEN]);
775 // Initialize the 'attackUnits' variable, which is used later on as an
776 // index to the KingDangerTable[] array. The initial value is based on
777 // the number and types of the enemy's attacking pieces, the number of
778 // attacked and undefended squares around our king, the square of the
779 // king, and the quality of the pawn shelter.
780 attackUnits = std::min(25, (ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) / 2)
781 + 3 * (ei.kingAdjacentZoneAttacksCount[Them] + popcount<Max15>(undefended))
782 + InitKingDanger[relative_square(Us, ksq)]
783 - mg_value(score) / 32;
785 // Analyse enemy's safe queen contact checks. First find undefended
786 // squares around the king attacked by enemy queen...
787 b = undefended & ei.attackedBy[Them][QUEEN] & ~pos.pieces(Them);
790 // ...then remove squares not supported by another enemy piece
791 b &= ( ei.attackedBy[Them][PAWN] | ei.attackedBy[Them][KNIGHT]
792 | ei.attackedBy[Them][BISHOP] | ei.attackedBy[Them][ROOK]);
794 attackUnits += QueenContactCheckBonus
796 * (Them == pos.side_to_move() ? 2 : 1);
799 // Analyse enemy's safe rook contact checks. First find undefended
800 // squares around the king attacked by enemy rooks...
801 b = undefended & ei.attackedBy[Them][ROOK] & ~pos.pieces(Them);
803 // Consider only squares where the enemy rook gives check
804 b &= PseudoAttacks[ROOK][ksq];
808 // ...then remove squares not supported by another enemy piece
809 b &= ( ei.attackedBy[Them][PAWN] | ei.attackedBy[Them][KNIGHT]
810 | ei.attackedBy[Them][BISHOP] | ei.attackedBy[Them][QUEEN]);
812 attackUnits += RookContactCheckBonus
814 * (Them == pos.side_to_move() ? 2 : 1);
817 // Analyse enemy's safe distance checks for sliders and knights
818 safe = ~(pos.pieces(Them) | ei.attackedBy[Us][0]);
820 b1 = pos.attacks_from<ROOK>(ksq) & safe;
821 b2 = pos.attacks_from<BISHOP>(ksq) & safe;
823 // Enemy queen safe checks
824 b = (b1 | b2) & ei.attackedBy[Them][QUEEN];
826 attackUnits += QueenCheckBonus * popcount<Max15>(b);
828 // Enemy rooks safe checks
829 b = b1 & ei.attackedBy[Them][ROOK];
831 attackUnits += RookCheckBonus * popcount<Max15>(b);
833 // Enemy bishops safe checks
834 b = b2 & ei.attackedBy[Them][BISHOP];
836 attackUnits += BishopCheckBonus * popcount<Max15>(b);
838 // Enemy knights safe checks
839 b = pos.attacks_from<KNIGHT>(ksq) & ei.attackedBy[Them][KNIGHT] & safe;
841 attackUnits += KnightCheckBonus * popcount<Max15>(b);
843 // To index KingDangerTable[] attackUnits must be in [0, 99] range
844 attackUnits = std::min(99, std::max(0, attackUnits));
846 // Finally, extract the king danger score from the KingDangerTable[]
847 // array and subtract the score from evaluation. Set also margins[]
848 // value that will be used for pruning because this value can sometimes
849 // be very big, and so capturing a single attacking piece can therefore
850 // result in a score change far bigger than the value of the captured piece.
851 score -= KingDangerTable[Us == Search::RootColor][attackUnits];
852 margins[Us] += mg_value(KingDangerTable[Us == Search::RootColor][attackUnits]);
856 TracedScores[Us][KING] = score;
862 // evaluate_passed_pawns<>() evaluates the passed pawns of the given color
865 Score evaluate_passed_pawns(const Position& pos, EvalInfo& ei) {
867 const Color Them = (Us == WHITE ? BLACK : WHITE);
869 Bitboard b, squaresToQueen, defendedSquares, unsafeSquares, supportingPawns;
870 Score score = SCORE_ZERO;
872 b = ei.pi->passed_pawns(Us);
878 Square s = pop_lsb(&b);
880 assert(pos.pawn_is_passed(Us, s));
882 int r = int(relative_rank(Us, s) - RANK_2);
883 int rr = r * (r - 1);
885 // Base bonus based on rank
886 Value mbonus = Value(20 * rr);
887 Value ebonus = Value(10 * (rr + r + 1));
891 Square blockSq = s + pawn_push(Us);
893 // Adjust bonus based on kings proximity
894 ebonus += Value(square_distance(pos.king_square(Them), blockSq) * 5 * rr);
895 ebonus -= Value(square_distance(pos.king_square(Us), blockSq) * 2 * rr);
897 // If blockSq is not the queening square then consider also a second push
898 if (rank_of(blockSq) != (Us == WHITE ? RANK_8 : RANK_1))
899 ebonus -= Value(square_distance(pos.king_square(Us), blockSq + pawn_push(Us)) * rr);
901 // If the pawn is free to advance, increase bonus
902 if (pos.is_empty(blockSq))
904 squaresToQueen = forward_bb(Us, s);
905 defendedSquares = squaresToQueen & ei.attackedBy[Us][0];
907 // If there is an enemy rook or queen attacking the pawn from behind,
908 // add all X-ray attacks by the rook or queen. Otherwise consider only
909 // the squares in the pawn's path attacked or occupied by the enemy.
910 if ( (forward_bb(Them, s) & pos.pieces(Them, ROOK, QUEEN))
911 && (forward_bb(Them, s) & pos.pieces(Them, ROOK, QUEEN) & pos.attacks_from<ROOK>(s)))
912 unsafeSquares = squaresToQueen;
914 unsafeSquares = squaresToQueen & (ei.attackedBy[Them][0] | pos.pieces(Them));
916 // If there aren't enemy attacks or pieces along the path to queen give
917 // huge bonus. Even bigger if we protect the pawn's path.
919 ebonus += Value(rr * (squaresToQueen == defendedSquares ? 17 : 15));
921 // OK, there are enemy attacks or pieces (but not pawns). Are those
922 // squares which are attacked by the enemy also attacked by us ?
923 // If yes, big bonus (but smaller than when there are no enemy attacks),
924 // if no, somewhat smaller bonus.
925 ebonus += Value(rr * ((unsafeSquares & defendedSquares) == unsafeSquares ? 13 : 8));
929 // Increase the bonus if the passed pawn is supported by a friendly pawn
930 // on the same rank and a bit smaller if it's on the previous rank.
931 supportingPawns = pos.pieces(Us, PAWN) & adjacent_files_bb(file_of(s));
932 if (supportingPawns & rank_bb(s))
933 ebonus += Value(r * 20);
935 else if (supportingPawns & rank_bb(s - pawn_push(Us)))
936 ebonus += Value(r * 12);
938 // Rook pawns are a special case: They are sometimes worse, and
939 // sometimes better than other passed pawns. It is difficult to find
940 // good rules for determining whether they are good or bad. For now,
941 // we try the following: Increase the value for rook pawns if the
942 // other side has no pieces apart from a knight, and decrease the
943 // value if the other side has a rook or queen.
944 if (file_of(s) == FILE_A || file_of(s) == FILE_H)
946 if (pos.non_pawn_material(Them) <= KnightValueMg)
947 ebonus += ebonus / 4;
948 else if (pos.pieces(Them, ROOK, QUEEN))
949 ebonus -= ebonus / 4;
951 score += make_score(mbonus, ebonus);
955 // Add the scores to the middle game and endgame eval
956 return apply_weight(score, Weights[PassedPawns]);
960 // evaluate_unstoppable_pawns() evaluates the unstoppable passed pawns for both sides, this is quite
961 // conservative and returns a winning score only when we are very sure that the pawn is winning.
963 Score evaluate_unstoppable_pawns(const Position& pos, EvalInfo& ei) {
965 Bitboard b, b2, blockers, supporters, queeningPath, candidates;
966 Square s, blockSq, queeningSquare;
967 Color c, winnerSide, loserSide;
968 bool pathDefended, opposed;
969 int pliesToGo, movesToGo, oppMovesToGo, sacptg, blockersCount, minKingDist, kingptg, d;
970 int pliesToQueen[] = { 256, 256 };
972 // Step 1. Hunt for unstoppable passed pawns. If we find at least one,
973 // record how many plies are required for promotion.
974 for (c = WHITE; c <= BLACK; c++)
976 // Skip if other side has non-pawn pieces
977 if (pos.non_pawn_material(~c))
980 b = ei.pi->passed_pawns(c);
985 queeningSquare = relative_square(c, file_of(s) | RANK_8);
986 queeningPath = forward_bb(c, s);
988 // Compute plies to queening and check direct advancement
989 movesToGo = rank_distance(s, queeningSquare) - int(relative_rank(c, s) == RANK_2);
990 oppMovesToGo = square_distance(pos.king_square(~c), queeningSquare) - int(c != pos.side_to_move());
991 pathDefended = ((ei.attackedBy[c][0] & queeningPath) == queeningPath);
993 if (movesToGo >= oppMovesToGo && !pathDefended)
996 // Opponent king cannot block because path is defended and position
997 // is not in check. So only friendly pieces can be blockers.
998 assert(!pos.checkers());
999 assert((queeningPath & pos.pieces()) == (queeningPath & pos.pieces(c)));
1001 // Add moves needed to free the path from friendly pieces and retest condition
1002 movesToGo += popcount<Max15>(queeningPath & pos.pieces(c));
1004 if (movesToGo >= oppMovesToGo && !pathDefended)
1007 pliesToGo = 2 * movesToGo - int(c == pos.side_to_move());
1008 pliesToQueen[c] = std::min(pliesToQueen[c], pliesToGo);
1012 // Step 2. If either side cannot promote at least three plies before the other side then situation
1013 // becomes too complex and we give up. Otherwise we determine the possibly "winning side"
1014 if (abs(pliesToQueen[WHITE] - pliesToQueen[BLACK]) < 3)
1017 winnerSide = (pliesToQueen[WHITE] < pliesToQueen[BLACK] ? WHITE : BLACK);
1018 loserSide = ~winnerSide;
1020 // Step 3. Can the losing side possibly create a new passed pawn and thus prevent the loss?
1021 b = candidates = pos.pieces(loserSide, PAWN);
1027 // Compute plies from queening
1028 queeningSquare = relative_square(loserSide, file_of(s) | RANK_8);
1029 movesToGo = rank_distance(s, queeningSquare) - int(relative_rank(loserSide, s) == RANK_2);
1030 pliesToGo = 2 * movesToGo - int(loserSide == pos.side_to_move());
1032 // Check if (without even considering any obstacles) we're too far away or doubled
1033 if ( pliesToQueen[winnerSide] + 3 <= pliesToGo
1034 || (forward_bb(loserSide, s) & pos.pieces(loserSide, PAWN)))
1038 // If any candidate is already a passed pawn it _may_ promote in time. We give up.
1039 if (candidates & ei.pi->passed_pawns(loserSide))
1042 // Step 4. Check new passed pawn creation through king capturing and pawn sacrifices
1048 sacptg = blockersCount = 0;
1049 minKingDist = kingptg = 256;
1051 // Compute plies from queening
1052 queeningSquare = relative_square(loserSide, file_of(s) | RANK_8);
1053 movesToGo = rank_distance(s, queeningSquare) - int(relative_rank(loserSide, s) == RANK_2);
1054 pliesToGo = 2 * movesToGo - int(loserSide == pos.side_to_move());
1056 // Generate list of blocking pawns and supporters
1057 supporters = adjacent_files_bb(file_of(s)) & candidates;
1058 opposed = forward_bb(loserSide, s) & pos.pieces(winnerSide, PAWN);
1059 blockers = passed_pawn_mask(loserSide, s) & pos.pieces(winnerSide, PAWN);
1063 // How many plies does it take to remove all the blocking pawns?
1066 blockSq = pop_lsb(&blockers);
1069 // Check pawns that can give support to overcome obstacle, for instance
1070 // black pawns: a4, b4 white: b2 then pawn in b4 is giving support.
1073 b2 = supporters & in_front_bb(winnerSide, blockSq + pawn_push(winnerSide));
1075 while (b2) // This while-loop could be replaced with LSB/MSB (depending on color)
1077 d = square_distance(blockSq, pop_lsb(&b2)) - 2;
1078 movesToGo = std::min(movesToGo, d);
1082 // Check pawns that can be sacrificed against the blocking pawn
1083 b2 = attack_span_mask(winnerSide, blockSq) & candidates & ~(1ULL << s);
1085 while (b2) // This while-loop could be replaced with LSB/MSB (depending on color)
1087 d = square_distance(blockSq, pop_lsb(&b2)) - 2;
1088 movesToGo = std::min(movesToGo, d);
1091 // If obstacle can be destroyed with an immediate pawn exchange / sacrifice,
1092 // it's not a real obstacle and we have nothing to add to pliesToGo.
1096 // Plies needed to sacrifice against all the blocking pawns
1097 sacptg += movesToGo * 2;
1100 // Plies needed for the king to capture all the blocking pawns
1101 d = square_distance(pos.king_square(loserSide), blockSq);
1102 minKingDist = std::min(minKingDist, d);
1103 kingptg = (minKingDist + blockersCount) * 2;
1106 // Check if pawn sacrifice plan _may_ save the day
1107 if (pliesToQueen[winnerSide] + 3 > pliesToGo + sacptg)
1110 // Check if king capture plan _may_ save the day (contains some false positives)
1111 if (pliesToQueen[winnerSide] + 3 > pliesToGo + kingptg)
1115 // Winning pawn is unstoppable and will promote as first, return big score
1116 Score score = make_score(0, (Value) 1280 - 32 * pliesToQueen[winnerSide]);
1117 return winnerSide == WHITE ? score : -score;
1121 // evaluate_space() computes the space evaluation for a given side. The
1122 // space evaluation is a simple bonus based on the number of safe squares
1123 // available for minor pieces on the central four files on ranks 2--4. Safe
1124 // squares one, two or three squares behind a friendly pawn are counted
1125 // twice. Finally, the space bonus is scaled by a weight taken from the
1126 // material hash table. The aim is to improve play on game opening.
1128 int evaluate_space(const Position& pos, EvalInfo& ei) {
1130 const Color Them = (Us == WHITE ? BLACK : WHITE);
1132 // Find the safe squares for our pieces inside the area defined by
1133 // SpaceMask[]. A square is unsafe if it is attacked by an enemy
1134 // pawn, or if it is undefended and attacked by an enemy piece.
1135 Bitboard safe = SpaceMask[Us]
1136 & ~pos.pieces(Us, PAWN)
1137 & ~ei.attackedBy[Them][PAWN]
1138 & (ei.attackedBy[Us][0] | ~ei.attackedBy[Them][0]);
1140 // Find all squares which are at most three squares behind some friendly pawn
1141 Bitboard behind = pos.pieces(Us, PAWN);
1142 behind |= (Us == WHITE ? behind >> 8 : behind << 8);
1143 behind |= (Us == WHITE ? behind >> 16 : behind << 16);
1145 // Since SpaceMask[Us] is fully on our half of the board
1146 assert(unsigned(safe >> (Us == WHITE ? 32 : 0)) == 0);
1148 // Count safe + (behind & safe) with a single popcount
1149 return popcount<Full>((Us == WHITE ? safe << 32 : safe >> 32) | (behind & safe));
1153 // interpolate() interpolates between a middle game and an endgame score,
1154 // based on game phase. It also scales the return value by a ScaleFactor array.
1156 Value interpolate(const Score& v, Phase ph, ScaleFactor sf) {
1158 assert(mg_value(v) > -VALUE_INFINITE && mg_value(v) < VALUE_INFINITE);
1159 assert(eg_value(v) > -VALUE_INFINITE && eg_value(v) < VALUE_INFINITE);
1160 assert(ph >= PHASE_ENDGAME && ph <= PHASE_MIDGAME);
1162 int ev = (eg_value(v) * int(sf)) / SCALE_FACTOR_NORMAL;
1163 int result = (mg_value(v) * int(ph) + ev * int(128 - ph)) / 128;
1164 return Value((result + GrainSize / 2) & ~(GrainSize - 1));
1168 // weight_option() computes the value of an evaluation weight, by combining
1169 // two UCI-configurable weights (midgame and endgame) with an internal weight.
1171 Score weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight) {
1173 // Scale option value from 100 to 256
1174 int mg = Options[mgOpt] * 256 / 100;
1175 int eg = Options[egOpt] * 256 / 100;
1177 return apply_weight(make_score(mg, eg), internalWeight);
1181 // A couple of little helpers used by tracing code, to_cp() converts a value to
1182 // a double in centipawns scale, trace_add() stores white and black scores.
1184 double to_cp(Value v) { return double(v) / double(PawnValueMg); }
1186 void trace_add(int idx, Score wScore, Score bScore) {
1188 TracedScores[WHITE][idx] = wScore;
1189 TracedScores[BLACK][idx] = bScore;
1193 // trace_row() is an helper function used by tracing code to register the
1194 // values of a single evaluation term.
1196 void trace_row(const char* name, int idx) {
1198 Score wScore = TracedScores[WHITE][idx];
1199 Score bScore = TracedScores[BLACK][idx];
1202 case PST: case IMBALANCE: case PAWN: case UNSTOPPABLE: case TOTAL:
1203 TraceStream << std::setw(20) << name << " | --- --- | --- --- | "
1204 << std::setw(6) << to_cp(mg_value(wScore)) << " "
1205 << std::setw(6) << to_cp(eg_value(wScore)) << " \n";
1208 TraceStream << std::setw(20) << name << " | " << std::noshowpos
1209 << std::setw(5) << to_cp(mg_value(wScore)) << " "
1210 << std::setw(5) << to_cp(eg_value(wScore)) << " | "
1211 << std::setw(5) << to_cp(mg_value(bScore)) << " "
1212 << std::setw(5) << to_cp(eg_value(bScore)) << " | "
1214 << std::setw(6) << to_cp(mg_value(wScore - bScore)) << " "
1215 << std::setw(6) << to_cp(eg_value(wScore - bScore)) << " \n";