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[2][8];
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.
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[2];
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[2];
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[2];
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[][64] = {
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[][8] = {
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(-1, 29), 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 // Rooks and queens on the 7th rank (modified by Joona Kiiski)
154 const Score RookOn7thBonus = make_score(47, 98);
155 const Score QueenOn7thBonus = make_score(27, 54);
157 // Rooks on open files (modified by Joona Kiiski)
158 const Score RookOpenFileBonus = make_score(43, 21);
159 const Score RookHalfOpenFileBonus = make_score(19, 10);
161 // Penalty for rooks trapped inside a friendly king which has lost the
163 const Value TrappedRookPenalty = Value(180);
165 // Penalty for a bishop on a1/h1 (a8/h8 for black) which is trapped by
166 // a friendly pawn on b2/g2 (b7/g7 for black). This can obviously only
167 // happen in Chess960 games.
168 const Score TrappedBishopA1H1Penalty = make_score(100, 100);
170 // Penalty for BNR that is not defended by anything
171 const Score UndefendedPiecePenalty = make_score(25, 10);
173 // The SpaceMask[Color] contains the area of the board which is considered
174 // by the space evaluation. In the middle game, each side is given a bonus
175 // based on how many squares inside this area are safe and available for
176 // friendly minor pieces.
177 const Bitboard SpaceMask[] = {
178 (1ULL << SQ_C2) | (1ULL << SQ_D2) | (1ULL << SQ_E2) | (1ULL << SQ_F2) |
179 (1ULL << SQ_C3) | (1ULL << SQ_D3) | (1ULL << SQ_E3) | (1ULL << SQ_F3) |
180 (1ULL << SQ_C4) | (1ULL << SQ_D4) | (1ULL << SQ_E4) | (1ULL << SQ_F4),
181 (1ULL << SQ_C7) | (1ULL << SQ_D7) | (1ULL << SQ_E7) | (1ULL << SQ_F7) |
182 (1ULL << SQ_C6) | (1ULL << SQ_D6) | (1ULL << SQ_E6) | (1ULL << SQ_F6) |
183 (1ULL << SQ_C5) | (1ULL << SQ_D5) | (1ULL << SQ_E5) | (1ULL << SQ_F5)
186 // King danger constants and variables. The king danger scores are taken
187 // from the KingDangerTable[]. Various little "meta-bonuses" measuring
188 // the strength of the enemy attack are added up into an integer, which
189 // is used as an index to KingDangerTable[].
191 // KingAttackWeights[PieceType] contains king attack weights by piece type
192 const int KingAttackWeights[] = { 0, 0, 2, 2, 3, 5 };
194 // Bonuses for enemy's safe checks
195 const int QueenContactCheckBonus = 6;
196 const int RookContactCheckBonus = 4;
197 const int QueenCheckBonus = 3;
198 const int RookCheckBonus = 2;
199 const int BishopCheckBonus = 1;
200 const int KnightCheckBonus = 1;
202 // InitKingDanger[Square] contains penalties based on the position of the
203 // defending king, indexed by king's square (from white's point of view).
204 const int InitKingDanger[] = {
205 2, 0, 2, 5, 5, 2, 0, 2,
206 2, 2, 4, 8, 8, 4, 2, 2,
207 7, 10, 12, 12, 12, 12, 10, 7,
208 15, 15, 15, 15, 15, 15, 15, 15,
209 15, 15, 15, 15, 15, 15, 15, 15,
210 15, 15, 15, 15, 15, 15, 15, 15,
211 15, 15, 15, 15, 15, 15, 15, 15,
212 15, 15, 15, 15, 15, 15, 15, 15
215 // KingDangerTable[Color][attackUnits] contains the actual king danger
216 // weighted scores, indexed by color and by a calculated integer number.
217 Score KingDangerTable[2][128];
219 // TracedTerms[Color][PieceType || TracedType] contains a breakdown of the
220 // evaluation terms, used when tracing.
221 Score TracedScores[2][16];
222 std::stringstream TraceStream;
225 PST = 8, IMBALANCE = 9, MOBILITY = 10, THREAT = 11,
226 PASSED = 12, UNSTOPPABLE = 13, SPACE = 14, TOTAL = 15
229 // Function prototypes
231 Value do_evaluate(const Position& pos, Value& margin);
234 void init_eval_info(const Position& pos, EvalInfo& ei);
236 template<Color Us, bool Trace>
237 Score evaluate_pieces_of_color(const Position& pos, EvalInfo& ei, Score& mobility);
239 template<Color Us, bool Trace>
240 Score evaluate_king(const Position& pos, EvalInfo& ei, Value margins[]);
243 Score evaluate_threats(const Position& pos, EvalInfo& ei);
246 int evaluate_space(const Position& pos, EvalInfo& ei);
249 Score evaluate_passed_pawns(const Position& pos, EvalInfo& ei);
251 Score evaluate_unstoppable_pawns(const Position& pos, EvalInfo& ei);
253 inline Score apply_weight(Score v, Score weight);
254 Value scale_by_game_phase(const Score& v, Phase ph, ScaleFactor sf);
255 Score weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight);
256 double to_cp(Value v);
257 void trace_add(int idx, Score term_w, Score term_b = SCORE_ZERO);
258 void trace_row(const char* name, int idx);
266 /// evaluate() is the main evaluation function. It always computes two
267 /// values, an endgame score and a middle game score, and interpolates
268 /// between them based on the remaining material.
270 Value evaluate(const Position& pos, Value& margin) {
271 return do_evaluate<false>(pos, margin);
275 /// init() computes evaluation weights from the corresponding UCI parameters
276 /// and setup king tables.
280 Weights[Mobility] = weight_option("Mobility (Middle Game)", "Mobility (Endgame)", WeightsInternal[Mobility]);
281 Weights[PassedPawns] = weight_option("Passed Pawns (Middle Game)", "Passed Pawns (Endgame)", WeightsInternal[PassedPawns]);
282 Weights[Space] = weight_option("Space", "Space", WeightsInternal[Space]);
283 Weights[KingDangerUs] = weight_option("Cowardice", "Cowardice", WeightsInternal[KingDangerUs]);
284 Weights[KingDangerThem] = weight_option("Aggressiveness", "Aggressiveness", WeightsInternal[KingDangerThem]);
286 // King safety is asymmetrical. Our king danger level is weighted by
287 // "Cowardice" UCI parameter, instead the opponent one by "Aggressiveness".
288 // If running in analysis mode, make sure we use symmetrical king safety. We
289 // do this by replacing both Weights[kingDangerUs] and Weights[kingDangerThem]
291 if (Options["UCI_AnalyseMode"])
292 Weights[KingDangerUs] = Weights[KingDangerThem] = (Weights[KingDangerUs] + Weights[KingDangerThem]) / 2;
294 const int MaxSlope = 30;
295 const int Peak = 1280;
297 for (int t = 0, i = 1; i < 100; i++)
299 t = std::min(Peak, std::min(int(0.4 * i * i), t + MaxSlope));
301 KingDangerTable[1][i] = apply_weight(make_score(t, 0), Weights[KingDangerUs]);
302 KingDangerTable[0][i] = apply_weight(make_score(t, 0), Weights[KingDangerThem]);
307 /// trace() is like evaluate() but instead of a value returns a string suitable
308 /// to be print on stdout with the detailed descriptions and values of each
309 /// evaluation term. Used mainly for debugging.
311 std::string trace(const Position& pos) {
316 RootColor = pos.side_to_move();
319 TraceStream << std::showpoint << std::showpos << std::fixed << std::setprecision(2);
320 memset(TracedScores, 0, 2 * 16 * sizeof(Score));
322 do_evaluate<true>(pos, margin);
324 totals = TraceStream.str();
327 TraceStream << std::setw(21) << "Eval term " << "| White | Black | Total \n"
328 << " | MG EG | MG EG | MG EG \n"
329 << "---------------------+-------------+-------------+---------------\n";
331 trace_row("Material, PST, Tempo", PST);
332 trace_row("Material imbalance", IMBALANCE);
333 trace_row("Pawns", PAWN);
334 trace_row("Knights", KNIGHT);
335 trace_row("Bishops", BISHOP);
336 trace_row("Rooks", ROOK);
337 trace_row("Queens", QUEEN);
338 trace_row("Mobility", MOBILITY);
339 trace_row("King safety", KING);
340 trace_row("Threats", THREAT);
341 trace_row("Passed pawns", PASSED);
342 trace_row("Unstoppable pawns", UNSTOPPABLE);
343 trace_row("Space", SPACE);
345 TraceStream << "---------------------+-------------+-------------+---------------\n";
346 trace_row("Total", TOTAL);
347 TraceStream << totals;
349 return TraceStream.str();
358 Value do_evaluate(const Position& pos, Value& margin) {
362 Score score, mobilityWhite, mobilityBlack;
364 assert(pos.thread() >= 0 && pos.thread() < MAX_THREADS);
365 assert(!pos.in_check());
367 // Initialize score by reading the incrementally updated scores included
368 // in the position object (material + piece square tables).
371 // margins[] store the uncertainty estimation of position's evaluation
372 // that typically is used by the search for pruning decisions.
373 margins[WHITE] = margins[BLACK] = VALUE_ZERO;
375 // Probe the material hash table
376 ei.mi = Threads[pos.thread()].materialTable.material_info(pos);
377 score += ei.mi->material_value();
379 // If we have a specialized evaluation function for the current material
380 // configuration, call it and return.
381 if (ei.mi->specialized_eval_exists())
384 return ei.mi->evaluate(pos);
387 // Probe the pawn hash table
388 ei.pi = Threads[pos.thread()].pawnTable.pawn_info(pos);
389 score += ei.pi->pawns_value();
391 // Initialize attack and king safety bitboards
392 init_eval_info<WHITE>(pos, ei);
393 init_eval_info<BLACK>(pos, ei);
395 // Evaluate pieces and mobility
396 score += evaluate_pieces_of_color<WHITE, Trace>(pos, ei, mobilityWhite)
397 - evaluate_pieces_of_color<BLACK, Trace>(pos, ei, mobilityBlack);
399 score += apply_weight(mobilityWhite - mobilityBlack, Weights[Mobility]);
401 // Evaluate kings after all other pieces because we need complete attack
402 // information when computing the king safety evaluation.
403 score += evaluate_king<WHITE, Trace>(pos, ei, margins)
404 - evaluate_king<BLACK, Trace>(pos, ei, margins);
406 // Evaluate tactical threats, we need full attack information including king
407 score += evaluate_threats<WHITE>(pos, ei)
408 - evaluate_threats<BLACK>(pos, ei);
410 // Evaluate passed pawns, we need full attack information including king
411 score += evaluate_passed_pawns<WHITE>(pos, ei)
412 - evaluate_passed_pawns<BLACK>(pos, ei);
414 // If one side has only a king, check whether exists any unstoppable passed pawn
415 if (!pos.non_pawn_material(WHITE) || !pos.non_pawn_material(BLACK))
416 score += evaluate_unstoppable_pawns(pos, ei);
418 // Evaluate space for both sides, only in middle-game.
419 if (ei.mi->space_weight())
421 int s = evaluate_space<WHITE>(pos, ei) - evaluate_space<BLACK>(pos, ei);
422 score += apply_weight(make_score(s * ei.mi->space_weight(), 0), Weights[Space]);
425 // Scale winning side if position is more drawish that what it appears
426 ScaleFactor sf = eg_value(score) > VALUE_DRAW ? ei.mi->scale_factor(pos, WHITE)
427 : ei.mi->scale_factor(pos, BLACK);
429 // If we don't already have an unusual scale factor, check for opposite
430 // colored bishop endgames, and use a lower scale for those.
431 if ( ei.mi->game_phase() < PHASE_MIDGAME
432 && pos.opposite_colored_bishops()
433 && sf == SCALE_FACTOR_NORMAL)
435 // Only the two bishops ?
436 if ( pos.non_pawn_material(WHITE) == BishopValueMidgame
437 && pos.non_pawn_material(BLACK) == BishopValueMidgame)
439 // Check for KBP vs KB with only a single pawn that is almost
440 // certainly a draw or at least two pawns.
441 bool one_pawn = (pos.piece_count(WHITE, PAWN) + pos.piece_count(BLACK, PAWN) == 1);
442 sf = one_pawn ? ScaleFactor(8) : ScaleFactor(32);
445 // Endgame with opposite-colored bishops, but also other pieces. Still
446 // a bit drawish, but not as drawish as with only the two bishops.
447 sf = ScaleFactor(50);
450 // Interpolate between the middle game and the endgame score
451 margin = margins[pos.side_to_move()];
452 Value v = scale_by_game_phase(score, ei.mi->game_phase(), sf);
454 // In case of tracing add all single evaluation contributions for both white and black
457 trace_add(PST, pos.value());
458 trace_add(IMBALANCE, ei.mi->material_value());
459 trace_add(PAWN, ei.pi->pawns_value());
460 trace_add(MOBILITY, apply_weight(mobilityWhite, Weights[Mobility]), apply_weight(mobilityBlack, Weights[Mobility]));
461 trace_add(THREAT, evaluate_threats<WHITE>(pos, ei), evaluate_threats<BLACK>(pos, ei));
462 trace_add(PASSED, evaluate_passed_pawns<WHITE>(pos, ei), evaluate_passed_pawns<BLACK>(pos, ei));
463 trace_add(UNSTOPPABLE, evaluate_unstoppable_pawns(pos, ei));
464 Score w = make_score(ei.mi->space_weight() * evaluate_space<WHITE>(pos, ei), 0);
465 Score b = make_score(ei.mi->space_weight() * evaluate_space<BLACK>(pos, ei), 0);
466 trace_add(SPACE, apply_weight(w, Weights[Space]), apply_weight(b, Weights[Space]));
467 trace_add(TOTAL, score);
468 TraceStream << "\nUncertainty margin: White: " << to_cp(margins[WHITE])
469 << ", Black: " << to_cp(margins[BLACK])
470 << "\nScaling: " << std::noshowpos
471 << std::setw(6) << 100.0 * ei.mi->game_phase() / 128.0 << "% MG, "
472 << std::setw(6) << 100.0 * (1.0 - ei.mi->game_phase() / 128.0) << "% * "
473 << std::setw(6) << (100.0 * sf) / SCALE_FACTOR_NORMAL << "% EG.\n"
474 << "Total evaluation: " << to_cp(v);
477 return pos.side_to_move() == WHITE ? v : -v;
481 // init_eval_info() initializes king bitboards for given color adding
482 // pawn attacks. To be done at the beginning of the evaluation.
485 void init_eval_info(const Position& pos, EvalInfo& ei) {
487 const Color Them = (Us == WHITE ? BLACK : WHITE);
489 Bitboard b = ei.attackedBy[Them][KING] = pos.attacks_from<KING>(pos.king_square(Them));
490 ei.attackedBy[Us][PAWN] = ei.pi->pawn_attacks(Us);
492 // Init king safety tables only if we are going to use them
493 if ( pos.piece_count(Us, QUEEN)
494 && pos.non_pawn_material(Us) >= QueenValueMidgame + RookValueMidgame)
496 ei.kingRing[Them] = (b | (Us == WHITE ? b >> 8 : b << 8));
497 b &= ei.attackedBy[Us][PAWN];
498 ei.kingAttackersCount[Us] = b ? popcount<Max15>(b) / 2 : 0;
499 ei.kingAdjacentZoneAttacksCount[Us] = ei.kingAttackersWeight[Us] = 0;
501 ei.kingRing[Them] = ei.kingAttackersCount[Us] = 0;
505 // evaluate_outposts() evaluates bishop and knight outposts squares
507 template<PieceType Piece, Color Us>
508 Score evaluate_outposts(const Position& pos, EvalInfo& ei, Square s) {
510 const Color Them = (Us == WHITE ? BLACK : WHITE);
512 assert (Piece == BISHOP || Piece == KNIGHT);
514 // Initial bonus based on square
515 Value bonus = OutpostBonus[Piece == BISHOP][relative_square(Us, s)];
517 // Increase bonus if supported by pawn, especially if the opponent has
518 // no minor piece which can exchange the outpost piece.
519 if (bonus && (ei.attackedBy[Us][PAWN] & s))
521 if ( !pos.pieces(KNIGHT, Them)
522 && !(same_color_squares(s) & pos.pieces(BISHOP, Them)))
523 bonus += bonus + bonus / 2;
527 return make_score(bonus, bonus);
531 // evaluate_pieces<>() assigns bonuses and penalties to the pieces of a given color
533 template<PieceType Piece, Color Us, bool Trace>
534 Score evaluate_pieces(const Position& pos, EvalInfo& ei, Score& mobility, Bitboard mobilityArea) {
540 Score score = SCORE_ZERO;
542 const Color Them = (Us == WHITE ? BLACK : WHITE);
543 const Square* pl = pos.piece_list(Us, Piece);
545 ei.attackedBy[Us][Piece] = 0;
547 while ((s = *pl++) != SQ_NONE)
549 // Find attacked squares, including x-ray attacks for bishops and rooks
550 if (Piece == KNIGHT || Piece == QUEEN)
551 b = pos.attacks_from<Piece>(s);
552 else if (Piece == BISHOP)
553 b = attacks_bb<BISHOP>(s, pos.pieces() ^ pos.pieces(QUEEN, Us));
554 else if (Piece == ROOK)
555 b = attacks_bb<ROOK>(s, pos.pieces() ^ pos.pieces(ROOK, QUEEN, Us));
559 ei.attackedBy[Us][Piece] |= b;
561 if (b & ei.kingRing[Them])
563 ei.kingAttackersCount[Us]++;
564 ei.kingAttackersWeight[Us] += KingAttackWeights[Piece];
565 Bitboard bb = (b & ei.attackedBy[Them][KING]);
567 ei.kingAdjacentZoneAttacksCount[Us] += popcount<Max15>(bb);
570 mob = (Piece != QUEEN ? popcount<Max15>(b & mobilityArea)
571 : popcount<Full >(b & mobilityArea));
573 mobility += MobilityBonus[Piece][mob];
575 // Add a bonus if a slider is pinning an enemy piece
576 if ( (Piece == BISHOP || Piece == ROOK || Piece == QUEEN)
577 && (PseudoAttacks[Piece][pos.king_square(Them)] & s))
579 b = BetweenBB[s][pos.king_square(Them)] & pos.pieces();
583 if (single_bit(b) && (b & pos.pieces(Them)))
584 score += ThreatBonus[Piece][type_of(pos.piece_on(first_1(b)))];
587 // Decrease score if we are attacked by an enemy pawn. Remaining part
588 // of threat evaluation must be done later when we have full attack info.
589 if (ei.attackedBy[Them][PAWN] & s)
590 score -= ThreatenedByPawnPenalty[Piece];
592 // Bishop and knight outposts squares
593 if ( (Piece == BISHOP || Piece == KNIGHT)
594 && !(pos.pieces(PAWN, Them) & attack_span_mask(Us, s)))
595 score += evaluate_outposts<Piece, Us>(pos, ei, s);
597 // Queen or rook on 7th rank
598 if ( (Piece == ROOK || Piece == QUEEN)
599 && relative_rank(Us, s) == RANK_7
600 && relative_rank(Us, pos.king_square(Them)) == RANK_8)
602 score += (Piece == ROOK ? RookOn7thBonus : QueenOn7thBonus);
605 // Special extra evaluation for bishops
606 if (Piece == BISHOP && pos.is_chess960())
608 // An important Chess960 pattern: A cornered bishop blocked by
609 // a friendly pawn diagonally in front of it is a very serious
610 // problem, especially when that pawn is also blocked.
611 if (s == relative_square(Us, SQ_A1) || s == relative_square(Us, SQ_H1))
613 Square d = pawn_push(Us) + (file_of(s) == FILE_A ? DELTA_E : DELTA_W);
614 if (pos.piece_on(s + d) == make_piece(Us, PAWN))
616 if (!pos.square_is_empty(s + d + pawn_push(Us)))
617 score -= 2*TrappedBishopA1H1Penalty;
618 else if (pos.piece_on(s + 2*d) == make_piece(Us, PAWN))
619 score -= TrappedBishopA1H1Penalty;
621 score -= TrappedBishopA1H1Penalty / 2;
626 // Special extra evaluation for rooks
629 // Open and half-open files
631 if (ei.pi->file_is_half_open(Us, f))
633 if (ei.pi->file_is_half_open(Them, f))
634 score += RookOpenFileBonus;
636 score += RookHalfOpenFileBonus;
639 // Penalize rooks which are trapped inside a king. Penalize more if
640 // king has lost right to castle.
641 if (mob > 6 || ei.pi->file_is_half_open(Us, f))
644 ksq = pos.king_square(Us);
646 if ( file_of(ksq) >= FILE_E
647 && file_of(s) > file_of(ksq)
648 && (relative_rank(Us, ksq) == RANK_1 || rank_of(ksq) == rank_of(s)))
650 // Is there a half-open file between the king and the edge of the board?
651 if (!ei.pi->has_open_file_to_right(Us, file_of(ksq)))
652 score -= make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2
653 : (TrappedRookPenalty - mob * 16), 0);
655 else if ( file_of(ksq) <= FILE_D
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_left(Us, file_of(ksq)))
661 score -= make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2
662 : (TrappedRookPenalty - mob * 16), 0);
668 TracedScores[Us][Piece] = score;
674 // evaluate_threats<>() assigns bonuses according to the type of attacking piece
675 // and the type of attacked one.
678 Score evaluate_threats(const Position& pos, EvalInfo& ei) {
680 const Color Them = (Us == WHITE ? BLACK : WHITE);
683 Score score = SCORE_ZERO;
685 // Undefended pieces get penalized even if not under attack
686 Bitboard undefended = pos.pieces(Them) & ~ei.attackedBy[Them][0];
687 const Bitboard undefendedMinors = undefended & (pos.pieces(BISHOP) | pos.pieces(KNIGHT));
689 if (undefendedMinors)
690 score += single_bit(undefendedMinors) ? UndefendedPiecePenalty
691 : UndefendedPiecePenalty * 2;
692 if (undefended & pos.pieces(ROOK))
693 score += UndefendedPiecePenalty;
695 // Enemy pieces not defended by a pawn and under our attack
696 Bitboard weakEnemies = pos.pieces(Them)
697 & ~ei.attackedBy[Them][PAWN]
698 & ei.attackedBy[Us][0];
702 // Add bonus according to type of attacked enemy piece and to the
703 // type of attacking piece, from knights to queens. Kings are not
704 // considered because are already handled in king evaluation.
705 for (PieceType pt1 = KNIGHT; pt1 < KING; pt1++)
707 b = ei.attackedBy[Us][pt1] & weakEnemies;
709 for (PieceType pt2 = PAWN; pt2 < KING; pt2++)
710 if (b & pos.pieces(pt2))
711 score += ThreatBonus[pt1][pt2];
717 // evaluate_pieces_of_color<>() assigns bonuses and penalties to all the
718 // pieces of a given color.
720 template<Color Us, bool Trace>
721 Score evaluate_pieces_of_color(const Position& pos, EvalInfo& ei, Score& mobility) {
723 const Color Them = (Us == WHITE ? BLACK : WHITE);
725 Score score = mobility = SCORE_ZERO;
727 // Do not include in mobility squares protected by enemy pawns or occupied by our pieces
728 const Bitboard mobilityArea = ~(ei.attackedBy[Them][PAWN] | pos.pieces(Us));
730 score += evaluate_pieces<KNIGHT, Us, Trace>(pos, ei, mobility, mobilityArea);
731 score += evaluate_pieces<BISHOP, Us, Trace>(pos, ei, mobility, mobilityArea);
732 score += evaluate_pieces<ROOK, Us, Trace>(pos, ei, mobility, mobilityArea);
733 score += evaluate_pieces<QUEEN, Us, Trace>(pos, ei, mobility, mobilityArea);
735 // Sum up all attacked squares
736 ei.attackedBy[Us][0] = ei.attackedBy[Us][PAWN] | ei.attackedBy[Us][KNIGHT]
737 | ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK]
738 | ei.attackedBy[Us][QUEEN] | ei.attackedBy[Us][KING];
743 // evaluate_king<>() assigns bonuses and penalties to a king of a given color
745 template<Color Us, bool Trace>
746 Score evaluate_king(const Position& pos, EvalInfo& ei, Value margins[]) {
748 const Color Them = (Us == WHITE ? BLACK : WHITE);
750 Bitboard undefended, b, b1, b2, safe;
752 const Square ksq = pos.king_square(Us);
755 Score score = ei.pi->king_shelter<Us>(pos, ksq);
757 // King safety. This is quite complicated, and is almost certainly far
758 // from optimally tuned.
759 if ( ei.kingAttackersCount[Them] >= 2
760 && ei.kingAdjacentZoneAttacksCount[Them])
762 // Find the attacked squares around the king which has no defenders
763 // apart from the king itself
764 undefended = ei.attackedBy[Them][0] & ei.attackedBy[Us][KING];
765 undefended &= ~( ei.attackedBy[Us][PAWN] | ei.attackedBy[Us][KNIGHT]
766 | ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK]
767 | ei.attackedBy[Us][QUEEN]);
769 // Initialize the 'attackUnits' variable, which is used later on as an
770 // index to the KingDangerTable[] array. The initial value is based on
771 // the number and types of the enemy's attacking pieces, the number of
772 // attacked and undefended squares around our king, the square of the
773 // king, and the quality of the pawn shelter.
774 attackUnits = std::min(25, (ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) / 2)
775 + 3 * (ei.kingAdjacentZoneAttacksCount[Them] + popcount<Max15>(undefended))
776 + InitKingDanger[relative_square(Us, ksq)]
777 - mg_value(ei.pi->king_shelter<Us>(pos, ksq)) / 32;
779 // Analyse enemy's safe queen contact checks. First find undefended
780 // squares around the king attacked by enemy queen...
781 b = undefended & ei.attackedBy[Them][QUEEN] & ~pos.pieces(Them);
784 // ...then remove squares not supported by another enemy piece
785 b &= ( ei.attackedBy[Them][PAWN] | ei.attackedBy[Them][KNIGHT]
786 | ei.attackedBy[Them][BISHOP] | ei.attackedBy[Them][ROOK]);
788 attackUnits += QueenContactCheckBonus
790 * (Them == pos.side_to_move() ? 2 : 1);
793 // Analyse enemy's safe rook contact checks. First find undefended
794 // squares around the king attacked by enemy rooks...
795 b = undefended & ei.attackedBy[Them][ROOK] & ~pos.pieces(Them);
797 // Consider only squares where the enemy rook gives check
798 b &= PseudoAttacks[ROOK][ksq];
802 // ...then remove squares not supported by another enemy piece
803 b &= ( ei.attackedBy[Them][PAWN] | ei.attackedBy[Them][KNIGHT]
804 | ei.attackedBy[Them][BISHOP] | ei.attackedBy[Them][QUEEN]);
806 attackUnits += RookContactCheckBonus
808 * (Them == pos.side_to_move() ? 2 : 1);
811 // Analyse enemy's safe distance checks for sliders and knights
812 safe = ~(pos.pieces(Them) | ei.attackedBy[Us][0]);
814 b1 = pos.attacks_from<ROOK>(ksq) & safe;
815 b2 = pos.attacks_from<BISHOP>(ksq) & safe;
817 // Enemy queen safe checks
818 b = (b1 | b2) & ei.attackedBy[Them][QUEEN];
820 attackUnits += QueenCheckBonus * popcount<Max15>(b);
822 // Enemy rooks safe checks
823 b = b1 & ei.attackedBy[Them][ROOK];
825 attackUnits += RookCheckBonus * popcount<Max15>(b);
827 // Enemy bishops safe checks
828 b = b2 & ei.attackedBy[Them][BISHOP];
830 attackUnits += BishopCheckBonus * popcount<Max15>(b);
832 // Enemy knights safe checks
833 b = pos.attacks_from<KNIGHT>(ksq) & ei.attackedBy[Them][KNIGHT] & safe;
835 attackUnits += KnightCheckBonus * popcount<Max15>(b);
837 // To index KingDangerTable[] attackUnits must be in [0, 99] range
838 attackUnits = std::min(99, std::max(0, attackUnits));
840 // Finally, extract the king danger score from the KingDangerTable[]
841 // array and subtract the score from evaluation. Set also margins[]
842 // value that will be used for pruning because this value can sometimes
843 // be very big, and so capturing a single attacking piece can therefore
844 // result in a score change far bigger than the value of the captured piece.
845 score -= KingDangerTable[Us == Eval::RootColor][attackUnits];
846 margins[Us] += mg_value(KingDangerTable[Us == Eval::RootColor][attackUnits]);
850 TracedScores[Us][KING] = score;
856 // evaluate_passed_pawns<>() evaluates the passed pawns of the given color
859 Score evaluate_passed_pawns(const Position& pos, EvalInfo& ei) {
861 const Color Them = (Us == WHITE ? BLACK : WHITE);
863 Bitboard b, squaresToQueen, defendedSquares, unsafeSquares, supportingPawns;
864 Score score = SCORE_ZERO;
866 b = ei.pi->passed_pawns(Us);
872 Square s = pop_1st_bit(&b);
874 assert(pos.pawn_is_passed(Us, s));
876 int r = int(relative_rank(Us, s) - RANK_2);
877 int rr = r * (r - 1);
879 // Base bonus based on rank
880 Value mbonus = Value(20 * rr);
881 Value ebonus = Value(10 * (rr + r + 1));
885 Square blockSq = s + pawn_push(Us);
887 // Adjust bonus based on kings proximity
888 ebonus += Value(square_distance(pos.king_square(Them), blockSq) * 5 * rr);
889 ebonus -= Value(square_distance(pos.king_square(Us), blockSq) * 2 * rr);
891 // If blockSq is not the queening square then consider also a second push
892 if (rank_of(blockSq) != (Us == WHITE ? RANK_8 : RANK_1))
893 ebonus -= Value(square_distance(pos.king_square(Us), blockSq + pawn_push(Us)) * rr);
895 // If the pawn is free to advance, increase bonus
896 if (pos.square_is_empty(blockSq))
898 squaresToQueen = squares_in_front_of(Us, s);
899 defendedSquares = squaresToQueen & ei.attackedBy[Us][0];
901 // If there is an enemy rook or queen attacking the pawn from behind,
902 // add all X-ray attacks by the rook or queen. Otherwise consider only
903 // the squares in the pawn's path attacked or occupied by the enemy.
904 if ( (squares_in_front_of(Them, s) & pos.pieces(ROOK, QUEEN, Them))
905 && (squares_in_front_of(Them, s) & pos.pieces(ROOK, QUEEN, Them) & pos.attacks_from<ROOK>(s)))
906 unsafeSquares = squaresToQueen;
908 unsafeSquares = squaresToQueen & (ei.attackedBy[Them][0] | pos.pieces(Them));
910 // If there aren't enemy attacks or pieces along the path to queen give
911 // huge bonus. Even bigger if we protect the pawn's path.
913 ebonus += Value(rr * (squaresToQueen == defendedSquares ? 17 : 15));
915 // OK, there are enemy attacks or pieces (but not pawns). Are those
916 // squares which are attacked by the enemy also attacked by us ?
917 // If yes, big bonus (but smaller than when there are no enemy attacks),
918 // if no, somewhat smaller bonus.
919 ebonus += Value(rr * ((unsafeSquares & defendedSquares) == unsafeSquares ? 13 : 8));
923 // Increase the bonus if the passed pawn is supported by a friendly pawn
924 // on the same rank and a bit smaller if it's on the previous rank.
925 supportingPawns = pos.pieces(PAWN, Us) & adjacent_files_bb(file_of(s));
926 if (supportingPawns & rank_bb(s))
927 ebonus += Value(r * 20);
929 else if (supportingPawns & rank_bb(s - pawn_push(Us)))
930 ebonus += Value(r * 12);
932 // Rook pawns are a special case: They are sometimes worse, and
933 // sometimes better than other passed pawns. It is difficult to find
934 // good rules for determining whether they are good or bad. For now,
935 // we try the following: Increase the value for rook pawns if the
936 // other side has no pieces apart from a knight, and decrease the
937 // value if the other side has a rook or queen.
938 if (file_of(s) == FILE_A || file_of(s) == FILE_H)
940 if (pos.non_pawn_material(Them) <= KnightValueMidgame)
941 ebonus += ebonus / 4;
942 else if (pos.pieces(ROOK, QUEEN, Them))
943 ebonus -= ebonus / 4;
945 score += make_score(mbonus, ebonus);
949 // Add the scores to the middle game and endgame eval
950 return apply_weight(score, Weights[PassedPawns]);
954 // evaluate_unstoppable_pawns() evaluates the unstoppable passed pawns for both sides, this is quite
955 // conservative and returns a winning score only when we are very sure that the pawn is winning.
957 Score evaluate_unstoppable_pawns(const Position& pos, EvalInfo& ei) {
959 Bitboard b, b2, blockers, supporters, queeningPath, candidates;
960 Square s, blockSq, queeningSquare;
961 Color c, winnerSide, loserSide;
962 bool pathDefended, opposed;
963 int pliesToGo, movesToGo, oppMovesToGo, sacptg, blockersCount, minKingDist, kingptg, d;
964 int pliesToQueen[] = { 256, 256 };
966 // Step 1. Hunt for unstoppable passed pawns. If we find at least one,
967 // record how many plies are required for promotion.
968 for (c = WHITE; c <= BLACK; c++)
970 // Skip if other side has non-pawn pieces
971 if (pos.non_pawn_material(~c))
974 b = ei.pi->passed_pawns(c);
979 queeningSquare = relative_square(c, make_square(file_of(s), RANK_8));
980 queeningPath = squares_in_front_of(c, s);
982 // Compute plies to queening and check direct advancement
983 movesToGo = rank_distance(s, queeningSquare) - int(relative_rank(c, s) == RANK_2);
984 oppMovesToGo = square_distance(pos.king_square(~c), queeningSquare) - int(c != pos.side_to_move());
985 pathDefended = ((ei.attackedBy[c][0] & queeningPath) == queeningPath);
987 if (movesToGo >= oppMovesToGo && !pathDefended)
990 // Opponent king cannot block because path is defended and position
991 // is not in check. So only friendly pieces can be blockers.
992 assert(!pos.in_check());
993 assert((queeningPath & pos.pieces()) == (queeningPath & pos.pieces(c)));
995 // Add moves needed to free the path from friendly pieces and retest condition
996 movesToGo += popcount<Max15>(queeningPath & pos.pieces(c));
998 if (movesToGo >= oppMovesToGo && !pathDefended)
1001 pliesToGo = 2 * movesToGo - int(c == pos.side_to_move());
1002 pliesToQueen[c] = std::min(pliesToQueen[c], pliesToGo);
1006 // Step 2. If either side cannot promote at least three plies before the other side then situation
1007 // becomes too complex and we give up. Otherwise we determine the possibly "winning side"
1008 if (abs(pliesToQueen[WHITE] - pliesToQueen[BLACK]) < 3)
1011 winnerSide = (pliesToQueen[WHITE] < pliesToQueen[BLACK] ? WHITE : BLACK);
1012 loserSide = ~winnerSide;
1014 // Step 3. Can the losing side possibly create a new passed pawn and thus prevent the loss?
1015 b = candidates = pos.pieces(PAWN, loserSide);
1019 s = pop_1st_bit(&b);
1021 // Compute plies from queening
1022 queeningSquare = relative_square(loserSide, make_square(file_of(s), RANK_8));
1023 movesToGo = rank_distance(s, queeningSquare) - int(relative_rank(loserSide, s) == RANK_2);
1024 pliesToGo = 2 * movesToGo - int(loserSide == pos.side_to_move());
1026 // Check if (without even considering any obstacles) we're too far away or doubled
1027 if ( pliesToQueen[winnerSide] + 3 <= pliesToGo
1028 || (squares_in_front_of(loserSide, s) & pos.pieces(PAWN, loserSide)))
1032 // If any candidate is already a passed pawn it _may_ promote in time. We give up.
1033 if (candidates & ei.pi->passed_pawns(loserSide))
1036 // Step 4. Check new passed pawn creation through king capturing and pawn sacrifices
1041 s = pop_1st_bit(&b);
1042 sacptg = blockersCount = 0;
1043 minKingDist = kingptg = 256;
1045 // Compute plies from queening
1046 queeningSquare = relative_square(loserSide, make_square(file_of(s), RANK_8));
1047 movesToGo = rank_distance(s, queeningSquare) - int(relative_rank(loserSide, s) == RANK_2);
1048 pliesToGo = 2 * movesToGo - int(loserSide == pos.side_to_move());
1050 // Generate list of blocking pawns and supporters
1051 supporters = adjacent_files_bb(file_of(s)) & candidates;
1052 opposed = squares_in_front_of(loserSide, s) & pos.pieces(PAWN, winnerSide);
1053 blockers = passed_pawn_mask(loserSide, s) & pos.pieces(PAWN, winnerSide);
1057 // How many plies does it take to remove all the blocking pawns?
1060 blockSq = pop_1st_bit(&blockers);
1063 // Check pawns that can give support to overcome obstacle, for instance
1064 // black pawns: a4, b4 white: b2 then pawn in b4 is giving support.
1067 b2 = supporters & in_front_bb(winnerSide, blockSq + pawn_push(winnerSide));
1069 while (b2) // This while-loop could be replaced with LSB/MSB (depending on color)
1071 d = square_distance(blockSq, pop_1st_bit(&b2)) - 2;
1072 movesToGo = std::min(movesToGo, d);
1076 // Check pawns that can be sacrificed against the blocking pawn
1077 b2 = attack_span_mask(winnerSide, blockSq) & candidates & ~(1ULL << s);
1079 while (b2) // This while-loop could be replaced with LSB/MSB (depending on color)
1081 d = square_distance(blockSq, pop_1st_bit(&b2)) - 2;
1082 movesToGo = std::min(movesToGo, d);
1085 // If obstacle can be destroyed with an immediate pawn exchange / sacrifice,
1086 // it's not a real obstacle and we have nothing to add to pliesToGo.
1090 // Plies needed to sacrifice against all the blocking pawns
1091 sacptg += movesToGo * 2;
1094 // Plies needed for the king to capture all the blocking pawns
1095 d = square_distance(pos.king_square(loserSide), blockSq);
1096 minKingDist = std::min(minKingDist, d);
1097 kingptg = (minKingDist + blockersCount) * 2;
1100 // Check if pawn sacrifice plan _may_ save the day
1101 if (pliesToQueen[winnerSide] + 3 > pliesToGo + sacptg)
1104 // Check if king capture plan _may_ save the day (contains some false positives)
1105 if (pliesToQueen[winnerSide] + 3 > pliesToGo + kingptg)
1109 // Winning pawn is unstoppable and will promote as first, return big score
1110 Score score = make_score(0, (Value) 0x500 - 0x20 * pliesToQueen[winnerSide]);
1111 return winnerSide == WHITE ? score : -score;
1115 // evaluate_space() computes the space evaluation for a given side. The
1116 // space evaluation is a simple bonus based on the number of safe squares
1117 // available for minor pieces on the central four files on ranks 2--4. Safe
1118 // squares one, two or three squares behind a friendly pawn are counted
1119 // twice. Finally, the space bonus is scaled by a weight taken from the
1120 // material hash table. The aim is to improve play on game opening.
1122 int evaluate_space(const Position& pos, EvalInfo& ei) {
1124 const Color Them = (Us == WHITE ? BLACK : WHITE);
1126 // Find the safe squares for our pieces inside the area defined by
1127 // SpaceMask[]. A square is unsafe if it is attacked by an enemy
1128 // pawn, or if it is undefended and attacked by an enemy piece.
1129 Bitboard safe = SpaceMask[Us]
1130 & ~pos.pieces(PAWN, Us)
1131 & ~ei.attackedBy[Them][PAWN]
1132 & (ei.attackedBy[Us][0] | ~ei.attackedBy[Them][0]);
1134 // Find all squares which are at most three squares behind some friendly pawn
1135 Bitboard behind = pos.pieces(PAWN, Us);
1136 behind |= (Us == WHITE ? behind >> 8 : behind << 8);
1137 behind |= (Us == WHITE ? behind >> 16 : behind << 16);
1139 return popcount<Max15>(safe) + popcount<Max15>(behind & safe);
1143 // apply_weight() applies an evaluation weight to a value trying to prevent overflow
1145 inline Score apply_weight(Score v, Score w) {
1146 return make_score((int(mg_value(v)) * mg_value(w)) / 0x100,
1147 (int(eg_value(v)) * eg_value(w)) / 0x100);
1151 // scale_by_game_phase() interpolates between a middle game and an endgame score,
1152 // based on game phase. It also scales the return value by a ScaleFactor array.
1154 Value scale_by_game_phase(const Score& v, Phase ph, ScaleFactor sf) {
1156 assert(mg_value(v) > -VALUE_INFINITE && mg_value(v) < VALUE_INFINITE);
1157 assert(eg_value(v) > -VALUE_INFINITE && eg_value(v) < VALUE_INFINITE);
1158 assert(ph >= PHASE_ENDGAME && ph <= PHASE_MIDGAME);
1160 int ev = (eg_value(v) * int(sf)) / SCALE_FACTOR_NORMAL;
1161 int result = (mg_value(v) * int(ph) + ev * int(128 - ph)) / 128;
1162 return Value((result + GrainSize / 2) & ~(GrainSize - 1));
1166 // weight_option() computes the value of an evaluation weight, by combining
1167 // two UCI-configurable weights (midgame and endgame) with an internal weight.
1169 Score weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight) {
1171 // Scale option value from 100 to 256
1172 int mg = Options[mgOpt] * 256 / 100;
1173 int eg = Options[egOpt] * 256 / 100;
1175 return apply_weight(make_score(mg, eg), internalWeight);
1179 // A couple of little helpers used by tracing code, to_cp() converts a value to
1180 // a double in centipawns scale, trace_add() stores white and black scores.
1182 double to_cp(Value v) { return double(v) / double(PawnValueMidgame); }
1184 void trace_add(int idx, Score wScore, Score bScore) {
1186 TracedScores[WHITE][idx] = wScore;
1187 TracedScores[BLACK][idx] = bScore;
1191 // trace_row() is an helper function used by tracing code to register the
1192 // values of a single evaluation term.
1194 void trace_row(const char* name, int idx) {
1196 Score wScore = TracedScores[WHITE][idx];
1197 Score bScore = TracedScores[BLACK][idx];
1200 case PST: case IMBALANCE: case PAWN: case UNSTOPPABLE: case TOTAL:
1201 TraceStream << std::setw(20) << name << " | --- --- | --- --- | "
1202 << std::setw(6) << to_cp(mg_value(wScore)) << " "
1203 << std::setw(6) << to_cp(eg_value(wScore)) << " \n";
1206 TraceStream << std::setw(20) << name << " | " << std::noshowpos
1207 << std::setw(5) << to_cp(mg_value(wScore)) << " "
1208 << std::setw(5) << to_cp(eg_value(wScore)) << " | "
1209 << std::setw(5) << to_cp(mg_value(bScore)) << " "
1210 << std::setw(5) << to_cp(eg_value(bScore)) << " | "
1212 << std::setw(6) << to_cp(mg_value(wScore - bScore)) << " "
1213 << std::setw(6) << to_cp(eg_value(wScore - bScore)) << " \n";