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 Score BishopPinBonus = make_score(66, 11);
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));
313 BishopPinBonus = make_score(Options["pin_open"], Options["pin_end"]);
317 /// trace() is like evaluate() but instead of a value returns a string suitable
318 /// to be print on stdout with the detailed descriptions and values of each
319 /// evaluation term. Used mainly for debugging.
321 std::string trace(const Position& pos) {
326 Search::RootColor = pos.side_to_move();
329 TraceStream << std::showpoint << std::showpos << std::fixed << std::setprecision(2);
330 memset(TracedScores, 0, 2 * 16 * sizeof(Score));
332 do_evaluate<true>(pos, margin);
334 totals = TraceStream.str();
337 TraceStream << std::setw(21) << "Eval term " << "| White | Black | Total \n"
338 << " | MG EG | MG EG | MG EG \n"
339 << "---------------------+-------------+-------------+---------------\n";
341 trace_row("Material, PST, Tempo", PST);
342 trace_row("Material imbalance", IMBALANCE);
343 trace_row("Pawns", PAWN);
344 trace_row("Knights", KNIGHT);
345 trace_row("Bishops", BISHOP);
346 trace_row("Rooks", ROOK);
347 trace_row("Queens", QUEEN);
348 trace_row("Mobility", MOBILITY);
349 trace_row("King safety", KING);
350 trace_row("Threats", THREAT);
351 trace_row("Passed pawns", PASSED);
352 trace_row("Unstoppable pawns", UNSTOPPABLE);
353 trace_row("Space", SPACE);
355 TraceStream << "---------------------+-------------+-------------+---------------\n";
356 trace_row("Total", TOTAL);
357 TraceStream << totals;
359 return TraceStream.str();
368 Value do_evaluate(const Position& pos, Value& margin) {
370 assert(!pos.checkers());
373 Value margins[COLOR_NB];
374 Score score, mobilityWhite, mobilityBlack;
375 Thread* th = pos.this_thread();
377 // margins[] store the uncertainty estimation of position's evaluation
378 // that typically is used by the search for pruning decisions.
379 margins[WHITE] = margins[BLACK] = VALUE_ZERO;
381 // Initialize score by reading the incrementally updated scores included
382 // in the position object (material + piece square tables) and adding
383 // Tempo bonus. Score is computed from the point of view of white.
384 score = pos.psq_score() + (pos.side_to_move() == WHITE ? Tempo : -Tempo);
386 // Probe the material hash table
387 ei.mi = Material::probe(pos, th->materialTable, th->endgames);
388 score += ei.mi->material_value();
390 // If we have a specialized evaluation function for the current material
391 // configuration, call it and return.
392 if (ei.mi->specialized_eval_exists())
395 return ei.mi->evaluate(pos);
398 // Probe the pawn hash table
399 ei.pi = Pawns::probe(pos, th->pawnsTable);
400 score += ei.pi->pawns_value();
402 // Initialize attack and king safety bitboards
403 init_eval_info<WHITE>(pos, ei);
404 init_eval_info<BLACK>(pos, ei);
406 // Evaluate pieces and mobility
407 score += evaluate_pieces_of_color<WHITE, Trace>(pos, ei, mobilityWhite)
408 - evaluate_pieces_of_color<BLACK, Trace>(pos, ei, mobilityBlack);
410 score += apply_weight(mobilityWhite - mobilityBlack, Weights[Mobility]);
412 // Evaluate kings after all other pieces because we need complete attack
413 // information when computing the king safety evaluation.
414 score += evaluate_king<WHITE, Trace>(pos, ei, margins)
415 - evaluate_king<BLACK, Trace>(pos, ei, margins);
417 // Evaluate tactical threats, we need full attack information including king
418 score += evaluate_threats<WHITE>(pos, ei)
419 - evaluate_threats<BLACK>(pos, ei);
421 // Evaluate passed pawns, we need full attack information including king
422 score += evaluate_passed_pawns<WHITE>(pos, ei)
423 - evaluate_passed_pawns<BLACK>(pos, ei);
425 // If one side has only a king, check whether exists any unstoppable passed pawn
426 if (!pos.non_pawn_material(WHITE) || !pos.non_pawn_material(BLACK))
427 score += evaluate_unstoppable_pawns(pos, ei);
429 // Evaluate space for both sides, only in middle-game.
430 if (ei.mi->space_weight())
432 int s = evaluate_space<WHITE>(pos, ei) - evaluate_space<BLACK>(pos, ei);
433 score += apply_weight(make_score(s * ei.mi->space_weight(), 0), Weights[Space]);
436 // Scale winning side if position is more drawish that what it appears
437 ScaleFactor sf = eg_value(score) > VALUE_DRAW ? ei.mi->scale_factor(pos, WHITE)
438 : ei.mi->scale_factor(pos, BLACK);
440 // If we don't already have an unusual scale factor, check for opposite
441 // colored bishop endgames, and use a lower scale for those.
442 if ( ei.mi->game_phase() < PHASE_MIDGAME
443 && pos.opposite_bishops()
444 && sf == SCALE_FACTOR_NORMAL)
446 // Only the two bishops ?
447 if ( pos.non_pawn_material(WHITE) == BishopValueMg
448 && pos.non_pawn_material(BLACK) == BishopValueMg)
450 // Check for KBP vs KB with only a single pawn that is almost
451 // certainly a draw or at least two pawns.
452 bool one_pawn = (pos.piece_count(WHITE, PAWN) + pos.piece_count(BLACK, PAWN) == 1);
453 sf = one_pawn ? ScaleFactor(8) : ScaleFactor(32);
456 // Endgame with opposite-colored bishops, but also other pieces. Still
457 // a bit drawish, but not as drawish as with only the two bishops.
458 sf = ScaleFactor(50);
461 margin = margins[pos.side_to_move()];
462 Value v = interpolate(score, ei.mi->game_phase(), sf);
464 // In case of tracing add all single evaluation contributions for both white and black
467 trace_add(PST, pos.psq_score());
468 trace_add(IMBALANCE, ei.mi->material_value());
469 trace_add(PAWN, ei.pi->pawns_value());
470 trace_add(MOBILITY, apply_weight(mobilityWhite, Weights[Mobility]), apply_weight(mobilityBlack, Weights[Mobility]));
471 trace_add(THREAT, evaluate_threats<WHITE>(pos, ei), evaluate_threats<BLACK>(pos, ei));
472 trace_add(PASSED, evaluate_passed_pawns<WHITE>(pos, ei), evaluate_passed_pawns<BLACK>(pos, ei));
473 trace_add(UNSTOPPABLE, evaluate_unstoppable_pawns(pos, ei));
474 Score w = make_score(ei.mi->space_weight() * evaluate_space<WHITE>(pos, ei), 0);
475 Score b = make_score(ei.mi->space_weight() * evaluate_space<BLACK>(pos, ei), 0);
476 trace_add(SPACE, apply_weight(w, Weights[Space]), apply_weight(b, Weights[Space]));
477 trace_add(TOTAL, score);
478 TraceStream << "\nUncertainty margin: White: " << to_cp(margins[WHITE])
479 << ", Black: " << to_cp(margins[BLACK])
480 << "\nScaling: " << std::noshowpos
481 << std::setw(6) << 100.0 * ei.mi->game_phase() / 128.0 << "% MG, "
482 << std::setw(6) << 100.0 * (1.0 - ei.mi->game_phase() / 128.0) << "% * "
483 << std::setw(6) << (100.0 * sf) / SCALE_FACTOR_NORMAL << "% EG.\n"
484 << "Total evaluation: " << to_cp(v);
487 return pos.side_to_move() == WHITE ? v : -v;
491 // init_eval_info() initializes king bitboards for given color adding
492 // pawn attacks. To be done at the beginning of the evaluation.
495 void init_eval_info(const Position& pos, EvalInfo& ei) {
497 const Color Them = (Us == WHITE ? BLACK : WHITE);
499 Bitboard b = ei.attackedBy[Them][KING] = pos.attacks_from<KING>(pos.king_square(Them));
500 ei.attackedBy[Us][PAWN] = ei.pi->pawn_attacks(Us);
502 // Init king safety tables only if we are going to use them
503 if ( pos.piece_count(Us, QUEEN)
504 && pos.non_pawn_material(Us) >= QueenValueMg + RookValueMg)
506 ei.kingRing[Them] = (b | (Us == WHITE ? b >> 8 : b << 8));
507 b &= ei.attackedBy[Us][PAWN];
508 ei.kingAttackersCount[Us] = b ? popcount<Max15>(b) / 2 : 0;
509 ei.kingAdjacentZoneAttacksCount[Us] = ei.kingAttackersWeight[Us] = 0;
511 ei.kingRing[Them] = ei.kingAttackersCount[Us] = 0;
515 // evaluate_outposts() evaluates bishop and knight outposts squares
517 template<PieceType Piece, Color Us>
518 Score evaluate_outposts(const Position& pos, EvalInfo& ei, Square s) {
520 const Color Them = (Us == WHITE ? BLACK : WHITE);
522 assert (Piece == BISHOP || Piece == KNIGHT);
524 // Initial bonus based on square
525 Value bonus = OutpostBonus[Piece == BISHOP][relative_square(Us, s)];
527 // Increase bonus if supported by pawn, especially if the opponent has
528 // no minor piece which can exchange the outpost piece.
529 if (bonus && (ei.attackedBy[Us][PAWN] & s))
531 if ( !pos.pieces(Them, KNIGHT)
532 && !(same_color_squares(s) & pos.pieces(Them, BISHOP)))
533 bonus += bonus + bonus / 2;
537 return make_score(bonus, bonus);
541 // evaluate_pieces<>() assigns bonuses and penalties to the pieces of a given color
543 template<PieceType Piece, Color Us, bool Trace>
544 Score evaluate_pieces(const Position& pos, EvalInfo& ei, Score& mobility, Bitboard mobilityArea) {
550 Score score = SCORE_ZERO;
552 const Color Them = (Us == WHITE ? BLACK : WHITE);
553 const Square* pl = pos.piece_list(Us, Piece);
555 ei.attackedBy[Us][Piece] = 0;
557 while ((s = *pl++) != SQ_NONE)
559 // Find attacked squares, including x-ray attacks for bishops and rooks
560 if (Piece == KNIGHT || Piece == QUEEN)
561 b = pos.attacks_from<Piece>(s);
562 else if (Piece == BISHOP)
563 b = attacks_bb<BISHOP>(s, pos.pieces() ^ pos.pieces(Us, QUEEN));
564 else if (Piece == ROOK)
565 b = attacks_bb<ROOK>(s, pos.pieces() ^ pos.pieces(Us, ROOK, QUEEN));
569 ei.attackedBy[Us][Piece] |= b;
571 if (b & ei.kingRing[Them])
573 ei.kingAttackersCount[Us]++;
574 ei.kingAttackersWeight[Us] += KingAttackWeights[Piece];
575 Bitboard bb = (b & ei.attackedBy[Them][KING]);
577 ei.kingAdjacentZoneAttacksCount[Us] += popcount<Max15>(bb);
580 mob = (Piece != QUEEN ? popcount<Max15>(b & mobilityArea)
581 : popcount<Full >(b & mobilityArea));
583 mobility += MobilityBonus[Piece][mob];
585 // Decrease score if we are attacked by an enemy pawn. Remaining part
586 // of threat evaluation must be done later when we have full attack info.
587 if (ei.attackedBy[Them][PAWN] & s)
588 score -= ThreatenedByPawnPenalty[Piece];
589 else if (Piece == BISHOP && (PseudoAttacks[Piece][pos.king_square(Them)] & s)) {
590 const Bitboard between = BetweenBB[s][pos.king_square(Them)] & pos.pieces();
591 if (!more_than_one(between))
592 score += BishopPinBonus;
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 += UndefendedMinorPenalty;
702 // Enemy pieces not defended by a pawn and under our attack
703 weakEnemies = pos.pieces(Them)
704 & ~ei.attackedBy[Them][PAWN]
705 & ei.attackedBy[Us][0];
710 // Add bonus according to type of attacked enemy piece and to the
711 // type of attacking piece, from knights to queens. Kings are not
712 // considered because are already handled in king evaluation.
713 for (PieceType pt1 = KNIGHT; pt1 < KING; pt1++)
715 b = ei.attackedBy[Us][pt1] & weakEnemies;
717 for (PieceType pt2 = PAWN; pt2 < KING; pt2++)
718 if (b & pos.pieces(pt2))
719 score += ThreatBonus[pt1][pt2];
725 // evaluate_pieces_of_color<>() assigns bonuses and penalties to all the
726 // pieces of a given color.
728 template<Color Us, bool Trace>
729 Score evaluate_pieces_of_color(const Position& pos, EvalInfo& ei, Score& mobility) {
731 const Color Them = (Us == WHITE ? BLACK : WHITE);
733 Score score = mobility = SCORE_ZERO;
735 // Do not include in mobility squares protected by enemy pawns or occupied by our pieces
736 const Bitboard mobilityArea = ~(ei.attackedBy[Them][PAWN] | pos.pieces(Us));
738 score += evaluate_pieces<KNIGHT, Us, Trace>(pos, ei, mobility, mobilityArea);
739 score += evaluate_pieces<BISHOP, Us, Trace>(pos, ei, mobility, mobilityArea);
740 score += evaluate_pieces<ROOK, Us, Trace>(pos, ei, mobility, mobilityArea);
741 score += evaluate_pieces<QUEEN, Us, Trace>(pos, ei, mobility, mobilityArea);
743 // Sum up all attacked squares
744 ei.attackedBy[Us][0] = ei.attackedBy[Us][PAWN] | ei.attackedBy[Us][KNIGHT]
745 | ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK]
746 | ei.attackedBy[Us][QUEEN] | ei.attackedBy[Us][KING];
751 // evaluate_king<>() assigns bonuses and penalties to a king of a given color
753 template<Color Us, bool Trace>
754 Score evaluate_king(const Position& pos, EvalInfo& ei, Value margins[]) {
756 const Color Them = (Us == WHITE ? BLACK : WHITE);
758 Bitboard undefended, b, b1, b2, safe;
760 const Square ksq = pos.king_square(Us);
762 // King shelter and enemy pawns storm
763 Score score = ei.pi->king_safety<Us>(pos, ksq);
765 // King safety. This is quite complicated, and is almost certainly far
766 // from optimally tuned.
767 if ( ei.kingAttackersCount[Them] >= 2
768 && ei.kingAdjacentZoneAttacksCount[Them])
770 // Find the attacked squares around the king which has no defenders
771 // apart from the king itself
772 undefended = ei.attackedBy[Them][0] & ei.attackedBy[Us][KING];
773 undefended &= ~( ei.attackedBy[Us][PAWN] | ei.attackedBy[Us][KNIGHT]
774 | ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK]
775 | ei.attackedBy[Us][QUEEN]);
777 // Initialize the 'attackUnits' variable, which is used later on as an
778 // index to the KingDangerTable[] array. The initial value is based on
779 // the number and types of the enemy's attacking pieces, the number of
780 // attacked and undefended squares around our king, the square of the
781 // king, and the quality of the pawn shelter.
782 attackUnits = std::min(25, (ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) / 2)
783 + 3 * (ei.kingAdjacentZoneAttacksCount[Them] + popcount<Max15>(undefended))
784 + InitKingDanger[relative_square(Us, ksq)]
785 - mg_value(score) / 32;
787 // Analyse enemy's safe queen contact checks. First find undefended
788 // squares around the king attacked by enemy queen...
789 b = undefended & ei.attackedBy[Them][QUEEN] & ~pos.pieces(Them);
792 // ...then remove squares not supported by another enemy piece
793 b &= ( ei.attackedBy[Them][PAWN] | ei.attackedBy[Them][KNIGHT]
794 | ei.attackedBy[Them][BISHOP] | ei.attackedBy[Them][ROOK]);
796 attackUnits += QueenContactCheckBonus
798 * (Them == pos.side_to_move() ? 2 : 1);
801 // Analyse enemy's safe rook contact checks. First find undefended
802 // squares around the king attacked by enemy rooks...
803 b = undefended & ei.attackedBy[Them][ROOK] & ~pos.pieces(Them);
805 // Consider only squares where the enemy rook gives check
806 b &= PseudoAttacks[ROOK][ksq];
810 // ...then remove squares not supported by another enemy piece
811 b &= ( ei.attackedBy[Them][PAWN] | ei.attackedBy[Them][KNIGHT]
812 | ei.attackedBy[Them][BISHOP] | ei.attackedBy[Them][QUEEN]);
814 attackUnits += RookContactCheckBonus
816 * (Them == pos.side_to_move() ? 2 : 1);
819 // Analyse enemy's safe distance checks for sliders and knights
820 safe = ~(pos.pieces(Them) | ei.attackedBy[Us][0]);
822 b1 = pos.attacks_from<ROOK>(ksq) & safe;
823 b2 = pos.attacks_from<BISHOP>(ksq) & safe;
825 // Enemy queen safe checks
826 b = (b1 | b2) & ei.attackedBy[Them][QUEEN];
828 attackUnits += QueenCheckBonus * popcount<Max15>(b);
830 // Enemy rooks safe checks
831 b = b1 & ei.attackedBy[Them][ROOK];
833 attackUnits += RookCheckBonus * popcount<Max15>(b);
835 // Enemy bishops safe checks
836 b = b2 & ei.attackedBy[Them][BISHOP];
838 attackUnits += BishopCheckBonus * popcount<Max15>(b);
840 // Enemy knights safe checks
841 b = pos.attacks_from<KNIGHT>(ksq) & ei.attackedBy[Them][KNIGHT] & safe;
843 attackUnits += KnightCheckBonus * popcount<Max15>(b);
845 // To index KingDangerTable[] attackUnits must be in [0, 99] range
846 attackUnits = std::min(99, std::max(0, attackUnits));
848 // Finally, extract the king danger score from the KingDangerTable[]
849 // array and subtract the score from evaluation. Set also margins[]
850 // value that will be used for pruning because this value can sometimes
851 // be very big, and so capturing a single attacking piece can therefore
852 // result in a score change far bigger than the value of the captured piece.
853 score -= KingDangerTable[Us == Search::RootColor][attackUnits];
854 margins[Us] += mg_value(KingDangerTable[Us == Search::RootColor][attackUnits]);
858 TracedScores[Us][KING] = score;
864 // evaluate_passed_pawns<>() evaluates the passed pawns of the given color
867 Score evaluate_passed_pawns(const Position& pos, EvalInfo& ei) {
869 const Color Them = (Us == WHITE ? BLACK : WHITE);
871 Bitboard b, squaresToQueen, defendedSquares, unsafeSquares, supportingPawns;
872 Score score = SCORE_ZERO;
874 b = ei.pi->passed_pawns(Us);
880 Square s = pop_lsb(&b);
882 assert(pos.pawn_is_passed(Us, s));
884 int r = int(relative_rank(Us, s) - RANK_2);
885 int rr = r * (r - 1);
887 // Base bonus based on rank
888 Value mbonus = Value(20 * rr);
889 Value ebonus = Value(10 * (rr + r + 1));
893 Square blockSq = s + pawn_push(Us);
895 // Adjust bonus based on kings proximity
896 ebonus += Value(square_distance(pos.king_square(Them), blockSq) * 5 * rr);
897 ebonus -= Value(square_distance(pos.king_square(Us), blockSq) * 2 * rr);
899 // If blockSq is not the queening square then consider also a second push
900 if (rank_of(blockSq) != (Us == WHITE ? RANK_8 : RANK_1))
901 ebonus -= Value(square_distance(pos.king_square(Us), blockSq + pawn_push(Us)) * rr);
903 // If the pawn is free to advance, increase bonus
904 if (pos.is_empty(blockSq))
906 squaresToQueen = forward_bb(Us, s);
907 defendedSquares = squaresToQueen & ei.attackedBy[Us][0];
909 // If there is an enemy rook or queen attacking the pawn from behind,
910 // add all X-ray attacks by the rook or queen. Otherwise consider only
911 // the squares in the pawn's path attacked or occupied by the enemy.
912 if ( (forward_bb(Them, s) & pos.pieces(Them, ROOK, QUEEN))
913 && (forward_bb(Them, s) & pos.pieces(Them, ROOK, QUEEN) & pos.attacks_from<ROOK>(s)))
914 unsafeSquares = squaresToQueen;
916 unsafeSquares = squaresToQueen & (ei.attackedBy[Them][0] | pos.pieces(Them));
918 // If there aren't enemy attacks or pieces along the path to queen give
919 // huge bonus. Even bigger if we protect the pawn's path.
921 ebonus += Value(rr * (squaresToQueen == defendedSquares ? 17 : 15));
923 // OK, there are enemy attacks or pieces (but not pawns). Are those
924 // squares which are attacked by the enemy also attacked by us ?
925 // If yes, big bonus (but smaller than when there are no enemy attacks),
926 // if no, somewhat smaller bonus.
927 ebonus += Value(rr * ((unsafeSquares & defendedSquares) == unsafeSquares ? 13 : 8));
931 // Increase the bonus if the passed pawn is supported by a friendly pawn
932 // on the same rank and a bit smaller if it's on the previous rank.
933 supportingPawns = pos.pieces(Us, PAWN) & adjacent_files_bb(file_of(s));
934 if (supportingPawns & rank_bb(s))
935 ebonus += Value(r * 20);
937 else if (supportingPawns & rank_bb(s - pawn_push(Us)))
938 ebonus += Value(r * 12);
940 // Rook pawns are a special case: They are sometimes worse, and
941 // sometimes better than other passed pawns. It is difficult to find
942 // good rules for determining whether they are good or bad. For now,
943 // we try the following: Increase the value for rook pawns if the
944 // other side has no pieces apart from a knight, and decrease the
945 // value if the other side has a rook or queen.
946 if (file_of(s) == FILE_A || file_of(s) == FILE_H)
948 if (pos.non_pawn_material(Them) <= KnightValueMg)
949 ebonus += ebonus / 4;
950 else if (pos.pieces(Them, ROOK, QUEEN))
951 ebonus -= ebonus / 4;
953 score += make_score(mbonus, ebonus);
957 // Add the scores to the middle game and endgame eval
958 return apply_weight(score, Weights[PassedPawns]);
962 // evaluate_unstoppable_pawns() evaluates the unstoppable passed pawns for both sides, this is quite
963 // conservative and returns a winning score only when we are very sure that the pawn is winning.
965 Score evaluate_unstoppable_pawns(const Position& pos, EvalInfo& ei) {
967 Bitboard b, b2, blockers, supporters, queeningPath, candidates;
968 Square s, blockSq, queeningSquare;
969 Color c, winnerSide, loserSide;
970 bool pathDefended, opposed;
971 int pliesToGo, movesToGo, oppMovesToGo, sacptg, blockersCount, minKingDist, kingptg, d;
972 int pliesToQueen[] = { 256, 256 };
974 // Step 1. Hunt for unstoppable passed pawns. If we find at least one,
975 // record how many plies are required for promotion.
976 for (c = WHITE; c <= BLACK; c++)
978 // Skip if other side has non-pawn pieces
979 if (pos.non_pawn_material(~c))
982 b = ei.pi->passed_pawns(c);
987 queeningSquare = relative_square(c, file_of(s) | RANK_8);
988 queeningPath = forward_bb(c, s);
990 // Compute plies to queening and check direct advancement
991 movesToGo = rank_distance(s, queeningSquare) - int(relative_rank(c, s) == RANK_2);
992 oppMovesToGo = square_distance(pos.king_square(~c), queeningSquare) - int(c != pos.side_to_move());
993 pathDefended = ((ei.attackedBy[c][0] & queeningPath) == queeningPath);
995 if (movesToGo >= oppMovesToGo && !pathDefended)
998 // Opponent king cannot block because path is defended and position
999 // is not in check. So only friendly pieces can be blockers.
1000 assert(!pos.checkers());
1001 assert((queeningPath & pos.pieces()) == (queeningPath & pos.pieces(c)));
1003 // Add moves needed to free the path from friendly pieces and retest condition
1004 movesToGo += popcount<Max15>(queeningPath & pos.pieces(c));
1006 if (movesToGo >= oppMovesToGo && !pathDefended)
1009 pliesToGo = 2 * movesToGo - int(c == pos.side_to_move());
1010 pliesToQueen[c] = std::min(pliesToQueen[c], pliesToGo);
1014 // Step 2. If either side cannot promote at least three plies before the other side then situation
1015 // becomes too complex and we give up. Otherwise we determine the possibly "winning side"
1016 if (abs(pliesToQueen[WHITE] - pliesToQueen[BLACK]) < 3)
1019 winnerSide = (pliesToQueen[WHITE] < pliesToQueen[BLACK] ? WHITE : BLACK);
1020 loserSide = ~winnerSide;
1022 // Step 3. Can the losing side possibly create a new passed pawn and thus prevent the loss?
1023 b = candidates = pos.pieces(loserSide, PAWN);
1029 // Compute plies from queening
1030 queeningSquare = relative_square(loserSide, file_of(s) | RANK_8);
1031 movesToGo = rank_distance(s, queeningSquare) - int(relative_rank(loserSide, s) == RANK_2);
1032 pliesToGo = 2 * movesToGo - int(loserSide == pos.side_to_move());
1034 // Check if (without even considering any obstacles) we're too far away or doubled
1035 if ( pliesToQueen[winnerSide] + 3 <= pliesToGo
1036 || (forward_bb(loserSide, s) & pos.pieces(loserSide, PAWN)))
1040 // If any candidate is already a passed pawn it _may_ promote in time. We give up.
1041 if (candidates & ei.pi->passed_pawns(loserSide))
1044 // Step 4. Check new passed pawn creation through king capturing and pawn sacrifices
1050 sacptg = blockersCount = 0;
1051 minKingDist = kingptg = 256;
1053 // Compute plies from queening
1054 queeningSquare = relative_square(loserSide, file_of(s) | RANK_8);
1055 movesToGo = rank_distance(s, queeningSquare) - int(relative_rank(loserSide, s) == RANK_2);
1056 pliesToGo = 2 * movesToGo - int(loserSide == pos.side_to_move());
1058 // Generate list of blocking pawns and supporters
1059 supporters = adjacent_files_bb(file_of(s)) & candidates;
1060 opposed = forward_bb(loserSide, s) & pos.pieces(winnerSide, PAWN);
1061 blockers = passed_pawn_mask(loserSide, s) & pos.pieces(winnerSide, PAWN);
1065 // How many plies does it take to remove all the blocking pawns?
1068 blockSq = pop_lsb(&blockers);
1071 // Check pawns that can give support to overcome obstacle, for instance
1072 // black pawns: a4, b4 white: b2 then pawn in b4 is giving support.
1075 b2 = supporters & in_front_bb(winnerSide, blockSq + pawn_push(winnerSide));
1077 while (b2) // This while-loop could be replaced with LSB/MSB (depending on color)
1079 d = square_distance(blockSq, pop_lsb(&b2)) - 2;
1080 movesToGo = std::min(movesToGo, d);
1084 // Check pawns that can be sacrificed against the blocking pawn
1085 b2 = attack_span_mask(winnerSide, blockSq) & candidates & ~(1ULL << s);
1087 while (b2) // This while-loop could be replaced with LSB/MSB (depending on color)
1089 d = square_distance(blockSq, pop_lsb(&b2)) - 2;
1090 movesToGo = std::min(movesToGo, d);
1093 // If obstacle can be destroyed with an immediate pawn exchange / sacrifice,
1094 // it's not a real obstacle and we have nothing to add to pliesToGo.
1098 // Plies needed to sacrifice against all the blocking pawns
1099 sacptg += movesToGo * 2;
1102 // Plies needed for the king to capture all the blocking pawns
1103 d = square_distance(pos.king_square(loserSide), blockSq);
1104 minKingDist = std::min(minKingDist, d);
1105 kingptg = (minKingDist + blockersCount) * 2;
1108 // Check if pawn sacrifice plan _may_ save the day
1109 if (pliesToQueen[winnerSide] + 3 > pliesToGo + sacptg)
1112 // Check if king capture plan _may_ save the day (contains some false positives)
1113 if (pliesToQueen[winnerSide] + 3 > pliesToGo + kingptg)
1117 // Winning pawn is unstoppable and will promote as first, return big score
1118 Score score = make_score(0, (Value) 1280 - 32 * pliesToQueen[winnerSide]);
1119 return winnerSide == WHITE ? score : -score;
1123 // evaluate_space() computes the space evaluation for a given side. The
1124 // space evaluation is a simple bonus based on the number of safe squares
1125 // available for minor pieces on the central four files on ranks 2--4. Safe
1126 // squares one, two or three squares behind a friendly pawn are counted
1127 // twice. Finally, the space bonus is scaled by a weight taken from the
1128 // material hash table. The aim is to improve play on game opening.
1130 int evaluate_space(const Position& pos, EvalInfo& ei) {
1132 const Color Them = (Us == WHITE ? BLACK : WHITE);
1134 // Find the safe squares for our pieces inside the area defined by
1135 // SpaceMask[]. A square is unsafe if it is attacked by an enemy
1136 // pawn, or if it is undefended and attacked by an enemy piece.
1137 Bitboard safe = SpaceMask[Us]
1138 & ~pos.pieces(Us, PAWN)
1139 & ~ei.attackedBy[Them][PAWN]
1140 & (ei.attackedBy[Us][0] | ~ei.attackedBy[Them][0]);
1142 // Find all squares which are at most three squares behind some friendly pawn
1143 Bitboard behind = pos.pieces(Us, PAWN);
1144 behind |= (Us == WHITE ? behind >> 8 : behind << 8);
1145 behind |= (Us == WHITE ? behind >> 16 : behind << 16);
1147 // Since SpaceMask[Us] is fully on our half of the board
1148 assert(unsigned(safe >> (Us == WHITE ? 32 : 0)) == 0);
1150 // Count safe + (behind & safe) with a single popcount
1151 return popcount<Full>((Us == WHITE ? safe << 32 : safe >> 32) | (behind & safe));
1155 // interpolate() interpolates between a middle game and an endgame score,
1156 // based on game phase. It also scales the return value by a ScaleFactor array.
1158 Value interpolate(const Score& v, Phase ph, ScaleFactor sf) {
1160 assert(mg_value(v) > -VALUE_INFINITE && mg_value(v) < VALUE_INFINITE);
1161 assert(eg_value(v) > -VALUE_INFINITE && eg_value(v) < VALUE_INFINITE);
1162 assert(ph >= PHASE_ENDGAME && ph <= PHASE_MIDGAME);
1164 int ev = (eg_value(v) * int(sf)) / SCALE_FACTOR_NORMAL;
1165 int result = (mg_value(v) * int(ph) + ev * int(128 - ph)) / 128;
1166 return Value((result + GrainSize / 2) & ~(GrainSize - 1));
1170 // weight_option() computes the value of an evaluation weight, by combining
1171 // two UCI-configurable weights (midgame and endgame) with an internal weight.
1173 Score weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight) {
1175 // Scale option value from 100 to 256
1176 int mg = Options[mgOpt] * 256 / 100;
1177 int eg = Options[egOpt] * 256 / 100;
1179 return apply_weight(make_score(mg, eg), internalWeight);
1183 // A couple of little helpers used by tracing code, to_cp() converts a value to
1184 // a double in centipawns scale, trace_add() stores white and black scores.
1186 double to_cp(Value v) { return double(v) / double(PawnValueMg); }
1188 void trace_add(int idx, Score wScore, Score bScore) {
1190 TracedScores[WHITE][idx] = wScore;
1191 TracedScores[BLACK][idx] = bScore;
1195 // trace_row() is an helper function used by tracing code to register the
1196 // values of a single evaluation term.
1198 void trace_row(const char* name, int idx) {
1200 Score wScore = TracedScores[WHITE][idx];
1201 Score bScore = TracedScores[BLACK][idx];
1204 case PST: case IMBALANCE: case PAWN: case UNSTOPPABLE: case TOTAL:
1205 TraceStream << std::setw(20) << name << " | --- --- | --- --- | "
1206 << std::setw(6) << to_cp(mg_value(wScore)) << " "
1207 << std::setw(6) << to_cp(eg_value(wScore)) << " \n";
1210 TraceStream << std::setw(20) << name << " | " << std::noshowpos
1211 << std::setw(5) << to_cp(mg_value(wScore)) << " "
1212 << std::setw(5) << to_cp(eg_value(wScore)) << " | "
1213 << std::setw(5) << to_cp(mg_value(bScore)) << " "
1214 << std::setw(5) << to_cp(eg_value(bScore)) << " | "
1216 << std::setw(6) << to_cp(mg_value(wScore - bScore)) << " "
1217 << std::setw(6) << to_cp(eg_value(wScore - bScore)) << " \n";