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 // The SpaceMask[Color] contains the area of the board which is considered
171 // by the space evaluation. In the middle game, each side is given a bonus
172 // based on how many squares inside this area are safe and available for
173 // friendly minor pieces.
174 const Bitboard SpaceMask[] = {
175 (1ULL << SQ_C2) | (1ULL << SQ_D2) | (1ULL << SQ_E2) | (1ULL << SQ_F2) |
176 (1ULL << SQ_C3) | (1ULL << SQ_D3) | (1ULL << SQ_E3) | (1ULL << SQ_F3) |
177 (1ULL << SQ_C4) | (1ULL << SQ_D4) | (1ULL << SQ_E4) | (1ULL << SQ_F4),
178 (1ULL << SQ_C7) | (1ULL << SQ_D7) | (1ULL << SQ_E7) | (1ULL << SQ_F7) |
179 (1ULL << SQ_C6) | (1ULL << SQ_D6) | (1ULL << SQ_E6) | (1ULL << SQ_F6) |
180 (1ULL << SQ_C5) | (1ULL << SQ_D5) | (1ULL << SQ_E5) | (1ULL << SQ_F5)
183 // King danger constants and variables. The king danger scores are taken
184 // from the KingDangerTable[]. Various little "meta-bonuses" measuring
185 // the strength of the enemy attack are added up into an integer, which
186 // is used as an index to KingDangerTable[].
188 // KingAttackWeights[PieceType] contains king attack weights by piece type
189 const int KingAttackWeights[] = { 0, 0, 2, 2, 3, 5 };
191 // Bonuses for enemy's safe checks
192 const int QueenContactCheckBonus = 6;
193 const int RookContactCheckBonus = 4;
194 const int QueenCheckBonus = 3;
195 const int RookCheckBonus = 2;
196 const int BishopCheckBonus = 1;
197 const int KnightCheckBonus = 1;
199 // InitKingDanger[Square] contains penalties based on the position of the
200 // defending king, indexed by king's square (from white's point of view).
201 const int InitKingDanger[] = {
202 2, 0, 2, 5, 5, 2, 0, 2,
203 2, 2, 4, 8, 8, 4, 2, 2,
204 7, 10, 12, 12, 12, 12, 10, 7,
205 15, 15, 15, 15, 15, 15, 15, 15,
206 15, 15, 15, 15, 15, 15, 15, 15,
207 15, 15, 15, 15, 15, 15, 15, 15,
208 15, 15, 15, 15, 15, 15, 15, 15,
209 15, 15, 15, 15, 15, 15, 15, 15
212 // KingDangerTable[Color][attackUnits] contains the actual king danger
213 // weighted scores, indexed by color and by a calculated integer number.
214 Score KingDangerTable[2][128];
216 // TracedTerms[Color][PieceType || TracedType] contains a breakdown of the
217 // evaluation terms, used when tracing.
218 Score TracedScores[2][16];
219 std::stringstream TraceStream;
222 PST = 8, IMBALANCE = 9, MOBILITY = 10, THREAT = 11,
223 PASSED = 12, UNSTOPPABLE = 13, SPACE = 14, TOTAL = 15
226 // Function prototypes
228 Value do_evaluate(const Position& pos, Value& margin);
231 void init_eval_info(const Position& pos, EvalInfo& ei);
233 template<Color Us, bool Trace>
234 Score evaluate_pieces_of_color(const Position& pos, EvalInfo& ei, Score& mobility);
236 template<Color Us, bool Trace>
237 Score evaluate_king(const Position& pos, EvalInfo& ei, Value margins[]);
240 Score evaluate_threats(const Position& pos, EvalInfo& ei);
243 int evaluate_space(const Position& pos, EvalInfo& ei);
246 Score evaluate_passed_pawns(const Position& pos, EvalInfo& ei);
248 Score evaluate_unstoppable_pawns(const Position& pos, EvalInfo& ei);
250 inline Score apply_weight(Score v, Score weight);
251 Value scale_by_game_phase(const Score& v, Phase ph, ScaleFactor sf);
252 Score weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight);
254 double to_cp(Value v);
255 void trace_add(int idx, Score term_w, Score term_b = SCORE_ZERO);
259 /// evaluate() is the main evaluation function. It always computes two
260 /// values, an endgame score and a middle game score, and interpolates
261 /// between them based on the remaining material.
262 Value evaluate(const Position& pos, Value& margin) { return do_evaluate<false>(pos, margin); }
267 Value do_evaluate(const Position& pos, Value& margin) {
271 Score score, mobilityWhite, mobilityBlack;
273 assert(pos.thread() >= 0 && pos.thread() < MAX_THREADS);
274 assert(!pos.in_check());
276 // Initialize score by reading the incrementally updated scores included
277 // in the position object (material + piece square tables).
280 // margins[] store the uncertainty estimation of position's evaluation
281 // that typically is used by the search for pruning decisions.
282 margins[WHITE] = margins[BLACK] = VALUE_ZERO;
284 // Probe the material hash table
285 ei.mi = Threads[pos.thread()].materialTable.material_info(pos);
286 score += ei.mi->material_value();
288 // If we have a specialized evaluation function for the current material
289 // configuration, call it and return.
290 if (ei.mi->specialized_eval_exists())
293 return ei.mi->evaluate(pos);
296 // Probe the pawn hash table
297 ei.pi = Threads[pos.thread()].pawnTable.pawn_info(pos);
298 score += ei.pi->pawns_value();
300 // Initialize attack and king safety bitboards
301 init_eval_info<WHITE>(pos, ei);
302 init_eval_info<BLACK>(pos, ei);
304 // Evaluate pieces and mobility
305 score += evaluate_pieces_of_color<WHITE, Trace>(pos, ei, mobilityWhite)
306 - evaluate_pieces_of_color<BLACK, Trace>(pos, ei, mobilityBlack);
308 score += apply_weight(mobilityWhite - mobilityBlack, Weights[Mobility]);
310 // Evaluate kings after all other pieces because we need complete attack
311 // information when computing the king safety evaluation.
312 score += evaluate_king<WHITE, Trace>(pos, ei, margins)
313 - evaluate_king<BLACK, Trace>(pos, ei, margins);
315 // Evaluate tactical threats, we need full attack information including king
316 score += evaluate_threats<WHITE>(pos, ei)
317 - evaluate_threats<BLACK>(pos, ei);
319 // Evaluate passed pawns, we need full attack information including king
320 score += evaluate_passed_pawns<WHITE>(pos, ei)
321 - evaluate_passed_pawns<BLACK>(pos, ei);
323 // If one side has only a king, check whether exists any unstoppable passed pawn
324 if (!pos.non_pawn_material(WHITE) || !pos.non_pawn_material(BLACK))
325 score += evaluate_unstoppable_pawns(pos, ei);
327 // Evaluate space for both sides, only in middle-game.
328 if (ei.mi->space_weight())
330 int s = evaluate_space<WHITE>(pos, ei) - evaluate_space<BLACK>(pos, ei);
331 score += apply_weight(make_score(s * ei.mi->space_weight(), 0), Weights[Space]);
334 // Scale winning side if position is more drawish that what it appears
335 ScaleFactor sf = eg_value(score) > VALUE_DRAW ? ei.mi->scale_factor(pos, WHITE)
336 : ei.mi->scale_factor(pos, BLACK);
338 // If we don't already have an unusual scale factor, check for opposite
339 // colored bishop endgames, and use a lower scale for those.
340 if ( ei.mi->game_phase() < PHASE_MIDGAME
341 && pos.opposite_colored_bishops()
342 && sf == SCALE_FACTOR_NORMAL)
344 // Only the two bishops ?
345 if ( pos.non_pawn_material(WHITE) == BishopValueMidgame
346 && pos.non_pawn_material(BLACK) == BishopValueMidgame)
348 // Check for KBP vs KB with only a single pawn that is almost
349 // certainly a draw or at least two pawns.
350 bool one_pawn = (pos.piece_count(WHITE, PAWN) + pos.piece_count(BLACK, PAWN) == 1);
351 sf = one_pawn ? ScaleFactor(8) : ScaleFactor(32);
354 // Endgame with opposite-colored bishops, but also other pieces. Still
355 // a bit drawish, but not as drawish as with only the two bishops.
356 sf = ScaleFactor(50);
359 // Interpolate between the middle game and the endgame score
360 margin = margins[pos.side_to_move()];
361 Value v = scale_by_game_phase(score, ei.mi->game_phase(), sf);
363 // In case of tracing add all single evaluation contributions for both white and black
366 trace_add(PST, pos.value());
367 trace_add(IMBALANCE, ei.mi->material_value());
368 trace_add(PAWN, ei.pi->pawns_value());
369 trace_add(MOBILITY, apply_weight(mobilityWhite, Weights[Mobility]), apply_weight(mobilityBlack, Weights[Mobility]));
370 trace_add(THREAT, evaluate_threats<WHITE>(pos, ei), evaluate_threats<BLACK>(pos, ei));
371 trace_add(PASSED, evaluate_passed_pawns<WHITE>(pos, ei), evaluate_passed_pawns<BLACK>(pos, ei));
372 trace_add(UNSTOPPABLE, evaluate_unstoppable_pawns(pos, ei));
373 Score w = make_score(ei.mi->space_weight() * evaluate_space<WHITE>(pos, ei), 0);
374 Score b = make_score(ei.mi->space_weight() * evaluate_space<BLACK>(pos, ei), 0);
375 trace_add(SPACE, apply_weight(w, Weights[Space]), apply_weight(b, Weights[Space]));
376 trace_add(TOTAL, score);
377 TraceStream << "\nUncertainty margin: White: " << to_cp(margins[WHITE])
378 << ", Black: " << to_cp(margins[BLACK])
379 << "\nScaling: " << std::noshowpos
380 << std::setw(6) << 100.0 * ei.mi->game_phase() / 128.0 << "% MG, "
381 << std::setw(6) << 100.0 * (1.0 - ei.mi->game_phase() / 128.0) << "% * "
382 << std::setw(6) << (100.0 * sf) / SCALE_FACTOR_NORMAL << "% EG.\n"
383 << "Total evaluation: " << to_cp(v);
386 return pos.side_to_move() == WHITE ? v : -v;
392 /// read_weights() reads evaluation weights from the corresponding UCI parameters
394 void read_evaluation_uci_options(Color us) {
396 // King safety is asymmetrical. Our king danger level is weighted by
397 // "Cowardice" UCI parameter, instead the opponent one by "Aggressiveness".
398 const int kingDangerUs = (us == WHITE ? KingDangerUs : KingDangerThem);
399 const int kingDangerThem = (us == WHITE ? KingDangerThem : KingDangerUs);
401 Weights[Mobility] = weight_option("Mobility (Middle Game)", "Mobility (Endgame)", WeightsInternal[Mobility]);
402 Weights[PassedPawns] = weight_option("Passed Pawns (Middle Game)", "Passed Pawns (Endgame)", WeightsInternal[PassedPawns]);
403 Weights[Space] = weight_option("Space", "Space", WeightsInternal[Space]);
404 Weights[kingDangerUs] = weight_option("Cowardice", "Cowardice", WeightsInternal[KingDangerUs]);
405 Weights[kingDangerThem] = weight_option("Aggressiveness", "Aggressiveness", WeightsInternal[KingDangerThem]);
407 // If running in analysis mode, make sure we use symmetrical king safety. We do this
408 // by replacing both Weights[kingDangerUs] and Weights[kingDangerThem] by their average.
409 if (Options["UCI_AnalyseMode"])
410 Weights[kingDangerUs] = Weights[kingDangerThem] = (Weights[kingDangerUs] + Weights[kingDangerThem]) / 2;
418 // init_eval_info() initializes king bitboards for given color adding
419 // pawn attacks. To be done at the beginning of the evaluation.
422 void init_eval_info(const Position& pos, EvalInfo& ei) {
424 const Color Them = (Us == WHITE ? BLACK : WHITE);
426 Bitboard b = ei.attackedBy[Them][KING] = pos.attacks_from<KING>(pos.king_square(Them));
427 ei.attackedBy[Us][PAWN] = ei.pi->pawn_attacks(Us);
429 // Init king safety tables only if we are going to use them
430 if ( pos.piece_count(Us, QUEEN)
431 && pos.non_pawn_material(Us) >= QueenValueMidgame + RookValueMidgame)
433 ei.kingRing[Them] = (b | (Us == WHITE ? b >> 8 : b << 8));
434 b &= ei.attackedBy[Us][PAWN];
435 ei.kingAttackersCount[Us] = b ? popcount<Max15>(b) / 2 : 0;
436 ei.kingAdjacentZoneAttacksCount[Us] = ei.kingAttackersWeight[Us] = 0;
438 ei.kingRing[Them] = ei.kingAttackersCount[Us] = 0;
442 // evaluate_outposts() evaluates bishop and knight outposts squares
444 template<PieceType Piece, Color Us>
445 Score evaluate_outposts(const Position& pos, EvalInfo& ei, Square s) {
447 const Color Them = (Us == WHITE ? BLACK : WHITE);
449 assert (Piece == BISHOP || Piece == KNIGHT);
451 // Initial bonus based on square
452 Value bonus = OutpostBonus[Piece == BISHOP][relative_square(Us, s)];
454 // Increase bonus if supported by pawn, especially if the opponent has
455 // no minor piece which can exchange the outpost piece.
456 if (bonus && (ei.attackedBy[Us][PAWN] & s))
458 if ( !pos.pieces(KNIGHT, Them)
459 && !(same_color_squares(s) & pos.pieces(BISHOP, Them)))
460 bonus += bonus + bonus / 2;
464 return make_score(bonus, bonus);
468 // evaluate_pieces<>() assigns bonuses and penalties to the pieces of a given color
470 template<PieceType Piece, Color Us, bool Trace>
471 Score evaluate_pieces(const Position& pos, EvalInfo& ei, Score& mobility, Bitboard mobilityArea) {
477 Score score = SCORE_ZERO;
479 const Color Them = (Us == WHITE ? BLACK : WHITE);
480 const Square* pl = pos.piece_list(Us, Piece);
482 ei.attackedBy[Us][Piece] = 0;
484 while ((s = *pl++) != SQ_NONE)
486 // Find attacked squares, including x-ray attacks for bishops and rooks
487 if (Piece == KNIGHT || Piece == QUEEN)
488 b = pos.attacks_from<Piece>(s);
489 else if (Piece == BISHOP)
490 b = attacks_bb<BISHOP>(s, pos.occupied_squares() & ~pos.pieces(QUEEN, Us));
491 else if (Piece == ROOK)
492 b = attacks_bb<ROOK>(s, pos.occupied_squares() & ~pos.pieces(ROOK, QUEEN, Us));
496 ei.attackedBy[Us][Piece] |= b;
498 if (b & ei.kingRing[Them])
500 ei.kingAttackersCount[Us]++;
501 ei.kingAttackersWeight[Us] += KingAttackWeights[Piece];
502 Bitboard bb = (b & ei.attackedBy[Them][KING]);
504 ei.kingAdjacentZoneAttacksCount[Us] += popcount<Max15>(bb);
507 mob = (Piece != QUEEN ? popcount<Max15>(b & mobilityArea)
508 : popcount<Full >(b & mobilityArea));
510 mobility += MobilityBonus[Piece][mob];
512 // Add a bonus if a slider is pinning an enemy piece
513 if ( (Piece == BISHOP || Piece == ROOK || Piece == QUEEN)
514 && (PseudoAttacks[Piece][pos.king_square(Them)] & s))
516 b = BetweenBB[s][pos.king_square(Them)] & pos.occupied_squares();
520 if (single_bit(b) && (b & pos.pieces(Them)))
521 score += ThreatBonus[Piece][type_of(pos.piece_on(first_1(b)))] / 2;
524 // Decrease score if we are attacked by an enemy pawn. Remaining part
525 // of threat evaluation must be done later when we have full attack info.
526 if (ei.attackedBy[Them][PAWN] & s)
527 score -= ThreatenedByPawnPenalty[Piece];
529 // Bishop and knight outposts squares
530 if ( (Piece == BISHOP || Piece == KNIGHT)
531 && !(pos.pieces(PAWN, Them) & attack_span_mask(Us, s)))
532 score += evaluate_outposts<Piece, Us>(pos, ei, s);
534 // Queen or rook on 7th rank
535 if ( (Piece == ROOK || Piece == QUEEN)
536 && relative_rank(Us, s) == RANK_7
537 && relative_rank(Us, pos.king_square(Them)) == RANK_8)
539 score += (Piece == ROOK ? RookOn7thBonus : QueenOn7thBonus);
542 // Special extra evaluation for bishops
543 if (Piece == BISHOP && pos.is_chess960())
545 // An important Chess960 pattern: A cornered bishop blocked by
546 // a friendly pawn diagonally in front of it is a very serious
547 // problem, especially when that pawn is also blocked.
548 if (s == relative_square(Us, SQ_A1) || s == relative_square(Us, SQ_H1))
550 Square d = pawn_push(Us) + (file_of(s) == FILE_A ? DELTA_E : DELTA_W);
551 if (pos.piece_on(s + d) == make_piece(Us, PAWN))
553 if (!pos.square_is_empty(s + d + pawn_push(Us)))
554 score -= 2*TrappedBishopA1H1Penalty;
555 else if (pos.piece_on(s + 2*d) == make_piece(Us, PAWN))
556 score -= TrappedBishopA1H1Penalty;
558 score -= TrappedBishopA1H1Penalty / 2;
563 // Special extra evaluation for rooks
566 // Open and half-open files
568 if (ei.pi->file_is_half_open(Us, f))
570 if (ei.pi->file_is_half_open(Them, f))
571 score += RookOpenFileBonus;
573 score += RookHalfOpenFileBonus;
576 // Penalize rooks which are trapped inside a king. Penalize more if
577 // king has lost right to castle.
578 if (mob > 6 || ei.pi->file_is_half_open(Us, f))
581 ksq = pos.king_square(Us);
583 if ( file_of(ksq) >= FILE_E
584 && file_of(s) > file_of(ksq)
585 && (relative_rank(Us, ksq) == RANK_1 || rank_of(ksq) == rank_of(s)))
587 // Is there a half-open file between the king and the edge of the board?
588 if (!ei.pi->has_open_file_to_right(Us, file_of(ksq)))
589 score -= make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2
590 : (TrappedRookPenalty - mob * 16), 0);
592 else if ( file_of(ksq) <= FILE_D
593 && file_of(s) < file_of(ksq)
594 && (relative_rank(Us, ksq) == RANK_1 || rank_of(ksq) == rank_of(s)))
596 // Is there a half-open file between the king and the edge of the board?
597 if (!ei.pi->has_open_file_to_left(Us, file_of(ksq)))
598 score -= make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2
599 : (TrappedRookPenalty - mob * 16), 0);
605 TracedScores[Us][Piece] = score;
611 // evaluate_threats<>() assigns bonuses according to the type of attacking piece
612 // and the type of attacked one.
615 Score evaluate_threats(const Position& pos, EvalInfo& ei) {
617 const Color Them = (Us == WHITE ? BLACK : WHITE);
620 Score score = SCORE_ZERO;
622 // Enemy pieces not defended by a pawn and under our attack
623 Bitboard weakEnemies = pos.pieces(Them)
624 & ~ei.attackedBy[Them][PAWN]
625 & ei.attackedBy[Us][0];
629 // Add bonus according to type of attacked enemy piece and to the
630 // type of attacking piece, from knights to queens. Kings are not
631 // considered because are already handled in king evaluation.
632 for (PieceType pt1 = KNIGHT; pt1 < KING; pt1++)
634 b = ei.attackedBy[Us][pt1] & weakEnemies;
636 for (PieceType pt2 = PAWN; pt2 < KING; pt2++)
637 if (b & pos.pieces(pt2))
638 score += ThreatBonus[pt1][pt2];
644 // evaluate_pieces_of_color<>() assigns bonuses and penalties to all the
645 // pieces of a given color.
647 template<Color Us, bool Trace>
648 Score evaluate_pieces_of_color(const Position& pos, EvalInfo& ei, Score& mobility) {
650 const Color Them = (Us == WHITE ? BLACK : WHITE);
652 Score score = mobility = SCORE_ZERO;
654 // Do not include in mobility squares protected by enemy pawns or occupied by our pieces
655 const Bitboard mobilityArea = ~(ei.attackedBy[Them][PAWN] | pos.pieces(Us));
657 score += evaluate_pieces<KNIGHT, Us, Trace>(pos, ei, mobility, mobilityArea);
658 score += evaluate_pieces<BISHOP, Us, Trace>(pos, ei, mobility, mobilityArea);
659 score += evaluate_pieces<ROOK, Us, Trace>(pos, ei, mobility, mobilityArea);
660 score += evaluate_pieces<QUEEN, Us, Trace>(pos, ei, mobility, mobilityArea);
662 // Sum up all attacked squares
663 ei.attackedBy[Us][0] = ei.attackedBy[Us][PAWN] | ei.attackedBy[Us][KNIGHT]
664 | ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK]
665 | ei.attackedBy[Us][QUEEN] | ei.attackedBy[Us][KING];
670 // evaluate_king<>() assigns bonuses and penalties to a king of a given color
672 template<Color Us, bool Trace>
673 Score evaluate_king(const Position& pos, EvalInfo& ei, Value margins[]) {
675 const Color Them = (Us == WHITE ? BLACK : WHITE);
677 Bitboard undefended, b, b1, b2, safe;
679 const Square ksq = pos.king_square(Us);
682 Score score = ei.pi->king_shelter<Us>(pos, ksq);
684 // King safety. This is quite complicated, and is almost certainly far
685 // from optimally tuned.
686 if ( ei.kingAttackersCount[Them] >= 2
687 && ei.kingAdjacentZoneAttacksCount[Them])
689 // Find the attacked squares around the king which has no defenders
690 // apart from the king itself
691 undefended = ei.attackedBy[Them][0] & ei.attackedBy[Us][KING];
692 undefended &= ~( ei.attackedBy[Us][PAWN] | ei.attackedBy[Us][KNIGHT]
693 | ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK]
694 | ei.attackedBy[Us][QUEEN]);
696 // Initialize the 'attackUnits' variable, which is used later on as an
697 // index to the KingDangerTable[] array. The initial value is based on
698 // the number and types of the enemy's attacking pieces, the number of
699 // attacked and undefended squares around our king, the square of the
700 // king, and the quality of the pawn shelter.
701 attackUnits = std::min(25, (ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) / 2)
702 + 3 * (ei.kingAdjacentZoneAttacksCount[Them] + popcount<Max15>(undefended))
703 + InitKingDanger[relative_square(Us, ksq)]
704 - mg_value(ei.pi->king_shelter<Us>(pos, ksq)) / 32;
706 // Analyse enemy's safe queen contact checks. First find undefended
707 // squares around the king attacked by enemy queen...
708 b = undefended & ei.attackedBy[Them][QUEEN] & ~pos.pieces(Them);
711 // ...then remove squares not supported by another enemy piece
712 b &= ( ei.attackedBy[Them][PAWN] | ei.attackedBy[Them][KNIGHT]
713 | ei.attackedBy[Them][BISHOP] | ei.attackedBy[Them][ROOK]);
715 attackUnits += QueenContactCheckBonus
717 * (Them == pos.side_to_move() ? 2 : 1);
720 // Analyse enemy's safe rook contact checks. First find undefended
721 // squares around the king attacked by enemy rooks...
722 b = undefended & ei.attackedBy[Them][ROOK] & ~pos.pieces(Them);
724 // Consider only squares where the enemy rook gives check
725 b &= PseudoAttacks[ROOK][ksq];
729 // ...then remove squares not supported by another enemy piece
730 b &= ( ei.attackedBy[Them][PAWN] | ei.attackedBy[Them][KNIGHT]
731 | ei.attackedBy[Them][BISHOP] | ei.attackedBy[Them][QUEEN]);
733 attackUnits += RookContactCheckBonus
735 * (Them == pos.side_to_move() ? 2 : 1);
738 // Analyse enemy's safe distance checks for sliders and knights
739 safe = ~(pos.pieces(Them) | ei.attackedBy[Us][0]);
741 b1 = pos.attacks_from<ROOK>(ksq) & safe;
742 b2 = pos.attacks_from<BISHOP>(ksq) & safe;
744 // Enemy queen safe checks
745 b = (b1 | b2) & ei.attackedBy[Them][QUEEN];
747 attackUnits += QueenCheckBonus * popcount<Max15>(b);
749 // Enemy rooks safe checks
750 b = b1 & ei.attackedBy[Them][ROOK];
752 attackUnits += RookCheckBonus * popcount<Max15>(b);
754 // Enemy bishops safe checks
755 b = b2 & ei.attackedBy[Them][BISHOP];
757 attackUnits += BishopCheckBonus * popcount<Max15>(b);
759 // Enemy knights safe checks
760 b = pos.attacks_from<KNIGHT>(ksq) & ei.attackedBy[Them][KNIGHT] & safe;
762 attackUnits += KnightCheckBonus * popcount<Max15>(b);
764 // To index KingDangerTable[] attackUnits must be in [0, 99] range
765 attackUnits = std::min(99, std::max(0, attackUnits));
767 // Finally, extract the king danger score from the KingDangerTable[]
768 // array and subtract the score from evaluation. Set also margins[]
769 // value that will be used for pruning because this value can sometimes
770 // be very big, and so capturing a single attacking piece can therefore
771 // result in a score change far bigger than the value of the captured piece.
772 score -= KingDangerTable[Us][attackUnits];
773 margins[Us] += mg_value(KingDangerTable[Us][attackUnits]);
777 TracedScores[Us][KING] = score;
783 // evaluate_passed_pawns<>() evaluates the passed pawns of the given color
786 Score evaluate_passed_pawns(const Position& pos, EvalInfo& ei) {
788 const Color Them = (Us == WHITE ? BLACK : WHITE);
790 Bitboard b, squaresToQueen, defendedSquares, unsafeSquares, supportingPawns;
791 Score score = SCORE_ZERO;
793 b = ei.pi->passed_pawns(Us);
799 Square s = pop_1st_bit(&b);
801 assert(pos.pawn_is_passed(Us, s));
803 int r = int(relative_rank(Us, s) - RANK_2);
804 int rr = r * (r - 1);
806 // Base bonus based on rank
807 Value mbonus = Value(20 * rr);
808 Value ebonus = Value(10 * (rr + r + 1));
812 Square blockSq = s + pawn_push(Us);
814 // Adjust bonus based on kings proximity
815 ebonus += Value(square_distance(pos.king_square(Them), blockSq) * 5 * rr);
816 ebonus -= Value(square_distance(pos.king_square(Us), blockSq) * 2 * rr);
818 // If blockSq is not the queening square then consider also a second push
819 if (rank_of(blockSq) != (Us == WHITE ? RANK_8 : RANK_1))
820 ebonus -= Value(square_distance(pos.king_square(Us), blockSq + pawn_push(Us)) * rr);
822 // If the pawn is free to advance, increase bonus
823 if (pos.square_is_empty(blockSq))
825 squaresToQueen = squares_in_front_of(Us, s);
826 defendedSquares = squaresToQueen & ei.attackedBy[Us][0];
828 // If there is an enemy rook or queen attacking the pawn from behind,
829 // add all X-ray attacks by the rook or queen. Otherwise consider only
830 // the squares in the pawn's path attacked or occupied by the enemy.
831 if ( (squares_in_front_of(Them, s) & pos.pieces(ROOK, QUEEN, Them))
832 && (squares_in_front_of(Them, s) & pos.pieces(ROOK, QUEEN, Them) & pos.attacks_from<ROOK>(s)))
833 unsafeSquares = squaresToQueen;
835 unsafeSquares = squaresToQueen & (ei.attackedBy[Them][0] | pos.pieces(Them));
837 // If there aren't enemy attacks or pieces along the path to queen give
838 // huge bonus. Even bigger if we protect the pawn's path.
840 ebonus += Value(rr * (squaresToQueen == defendedSquares ? 17 : 15));
842 // OK, there are enemy attacks or pieces (but not pawns). Are those
843 // squares which are attacked by the enemy also attacked by us ?
844 // If yes, big bonus (but smaller than when there are no enemy attacks),
845 // if no, somewhat smaller bonus.
846 ebonus += Value(rr * ((unsafeSquares & defendedSquares) == unsafeSquares ? 13 : 8));
850 // Increase the bonus if the passed pawn is supported by a friendly pawn
851 // on the same rank and a bit smaller if it's on the previous rank.
852 supportingPawns = pos.pieces(PAWN, Us) & adjacent_files_bb(file_of(s));
853 if (supportingPawns & rank_bb(s))
854 ebonus += Value(r * 20);
856 else if (supportingPawns & rank_bb(s - pawn_push(Us)))
857 ebonus += Value(r * 12);
859 // Rook pawns are a special case: They are sometimes worse, and
860 // sometimes better than other passed pawns. It is difficult to find
861 // good rules for determining whether they are good or bad. For now,
862 // we try the following: Increase the value for rook pawns if the
863 // other side has no pieces apart from a knight, and decrease the
864 // value if the other side has a rook or queen.
865 if (file_of(s) == FILE_A || file_of(s) == FILE_H)
867 if (pos.non_pawn_material(Them) <= KnightValueMidgame)
868 ebonus += ebonus / 4;
869 else if (pos.pieces(ROOK, QUEEN, Them))
870 ebonus -= ebonus / 4;
872 score += make_score(mbonus, ebonus);
876 // Add the scores to the middle game and endgame eval
877 return apply_weight(score, Weights[PassedPawns]);
881 // evaluate_unstoppable_pawns() evaluates the unstoppable passed pawns for both sides, this is quite
882 // conservative and returns a winning score only when we are very sure that the pawn is winning.
884 Score evaluate_unstoppable_pawns(const Position& pos, EvalInfo& ei) {
886 Bitboard b, b2, blockers, supporters, queeningPath, candidates;
887 Square s, blockSq, queeningSquare;
888 Color c, winnerSide, loserSide;
889 bool pathDefended, opposed;
890 int pliesToGo, movesToGo, oppMovesToGo, sacptg, blockersCount, minKingDist, kingptg, d;
891 int pliesToQueen[] = { 256, 256 };
893 // Step 1. Hunt for unstoppable passed pawns. If we find at least one,
894 // record how many plies are required for promotion.
895 for (c = WHITE; c <= BLACK; c++)
897 // Skip if other side has non-pawn pieces
898 if (pos.non_pawn_material(~c))
901 b = ei.pi->passed_pawns(c);
906 queeningSquare = relative_square(c, make_square(file_of(s), RANK_8));
907 queeningPath = squares_in_front_of(c, s);
909 // Compute plies to queening and check direct advancement
910 movesToGo = rank_distance(s, queeningSquare) - int(relative_rank(c, s) == RANK_2);
911 oppMovesToGo = square_distance(pos.king_square(~c), queeningSquare) - int(c != pos.side_to_move());
912 pathDefended = ((ei.attackedBy[c][0] & queeningPath) == queeningPath);
914 if (movesToGo >= oppMovesToGo && !pathDefended)
917 // Opponent king cannot block because path is defended and position
918 // is not in check. So only friendly pieces can be blockers.
919 assert(!pos.in_check());
920 assert((queeningPath & pos.occupied_squares()) == (queeningPath & pos.pieces(c)));
922 // Add moves needed to free the path from friendly pieces and retest condition
923 movesToGo += popcount<Max15>(queeningPath & pos.pieces(c));
925 if (movesToGo >= oppMovesToGo && !pathDefended)
928 pliesToGo = 2 * movesToGo - int(c == pos.side_to_move());
929 pliesToQueen[c] = std::min(pliesToQueen[c], pliesToGo);
933 // Step 2. If either side cannot promote at least three plies before the other side then situation
934 // becomes too complex and we give up. Otherwise we determine the possibly "winning side"
935 if (abs(pliesToQueen[WHITE] - pliesToQueen[BLACK]) < 3)
938 winnerSide = (pliesToQueen[WHITE] < pliesToQueen[BLACK] ? WHITE : BLACK);
939 loserSide = ~winnerSide;
941 // Step 3. Can the losing side possibly create a new passed pawn and thus prevent the loss?
942 b = candidates = pos.pieces(PAWN, loserSide);
948 // Compute plies from queening
949 queeningSquare = relative_square(loserSide, make_square(file_of(s), RANK_8));
950 movesToGo = rank_distance(s, queeningSquare) - int(relative_rank(loserSide, s) == RANK_2);
951 pliesToGo = 2 * movesToGo - int(loserSide == pos.side_to_move());
953 // Check if (without even considering any obstacles) we're too far away or doubled
954 if ( pliesToQueen[winnerSide] + 3 <= pliesToGo
955 || (squares_in_front_of(loserSide, s) & pos.pieces(PAWN, loserSide)))
959 // If any candidate is already a passed pawn it _may_ promote in time. We give up.
960 if (candidates & ei.pi->passed_pawns(loserSide))
963 // Step 4. Check new passed pawn creation through king capturing and pawn sacrifices
969 sacptg = blockersCount = 0;
970 minKingDist = kingptg = 256;
972 // Compute plies from queening
973 queeningSquare = relative_square(loserSide, make_square(file_of(s), RANK_8));
974 movesToGo = rank_distance(s, queeningSquare) - int(relative_rank(loserSide, s) == RANK_2);
975 pliesToGo = 2 * movesToGo - int(loserSide == pos.side_to_move());
977 // Generate list of blocking pawns and supporters
978 supporters = adjacent_files_bb(file_of(s)) & candidates;
979 opposed = squares_in_front_of(loserSide, s) & pos.pieces(PAWN, winnerSide);
980 blockers = passed_pawn_mask(loserSide, s) & pos.pieces(PAWN, winnerSide);
984 // How many plies does it take to remove all the blocking pawns?
987 blockSq = pop_1st_bit(&blockers);
990 // Check pawns that can give support to overcome obstacle, for instance
991 // black pawns: a4, b4 white: b2 then pawn in b4 is giving support.
994 b2 = supporters & in_front_bb(winnerSide, blockSq + pawn_push(winnerSide));
996 while (b2) // This while-loop could be replaced with LSB/MSB (depending on color)
998 d = square_distance(blockSq, pop_1st_bit(&b2)) - 2;
999 movesToGo = std::min(movesToGo, d);
1003 // Check pawns that can be sacrificed against the blocking pawn
1004 b2 = attack_span_mask(winnerSide, blockSq) & candidates & ~(1ULL << s);
1006 while (b2) // This while-loop could be replaced with LSB/MSB (depending on color)
1008 d = square_distance(blockSq, pop_1st_bit(&b2)) - 2;
1009 movesToGo = std::min(movesToGo, d);
1012 // If obstacle can be destroyed with an immediate pawn exchange / sacrifice,
1013 // it's not a real obstacle and we have nothing to add to pliesToGo.
1017 // Plies needed to sacrifice against all the blocking pawns
1018 sacptg += movesToGo * 2;
1021 // Plies needed for the king to capture all the blocking pawns
1022 d = square_distance(pos.king_square(loserSide), blockSq);
1023 minKingDist = std::min(minKingDist, d);
1024 kingptg = (minKingDist + blockersCount) * 2;
1027 // Check if pawn sacrifice plan _may_ save the day
1028 if (pliesToQueen[winnerSide] + 3 > pliesToGo + sacptg)
1031 // Check if king capture plan _may_ save the day (contains some false positives)
1032 if (pliesToQueen[winnerSide] + 3 > pliesToGo + kingptg)
1036 // Winning pawn is unstoppable and will promote as first, return big score
1037 Score score = make_score(0, (Value) 0x500 - 0x20 * pliesToQueen[winnerSide]);
1038 return winnerSide == WHITE ? score : -score;
1042 // evaluate_space() computes the space evaluation for a given side. The
1043 // space evaluation is a simple bonus based on the number of safe squares
1044 // available for minor pieces on the central four files on ranks 2--4. Safe
1045 // squares one, two or three squares behind a friendly pawn are counted
1046 // twice. Finally, the space bonus is scaled by a weight taken from the
1047 // material hash table. The aim is to improve play on game opening.
1049 int evaluate_space(const Position& pos, EvalInfo& ei) {
1051 const Color Them = (Us == WHITE ? BLACK : WHITE);
1053 // Find the safe squares for our pieces inside the area defined by
1054 // SpaceMask[]. A square is unsafe if it is attacked by an enemy
1055 // pawn, or if it is undefended and attacked by an enemy piece.
1056 Bitboard safe = SpaceMask[Us]
1057 & ~pos.pieces(PAWN, Us)
1058 & ~ei.attackedBy[Them][PAWN]
1059 & (ei.attackedBy[Us][0] | ~ei.attackedBy[Them][0]);
1061 // Find all squares which are at most three squares behind some friendly pawn
1062 Bitboard behind = pos.pieces(PAWN, Us);
1063 behind |= (Us == WHITE ? behind >> 8 : behind << 8);
1064 behind |= (Us == WHITE ? behind >> 16 : behind << 16);
1066 return popcount<Max15>(safe) + popcount<Max15>(behind & safe);
1070 // apply_weight() applies an evaluation weight to a value trying to prevent overflow
1072 inline Score apply_weight(Score v, Score w) {
1073 return make_score((int(mg_value(v)) * mg_value(w)) / 0x100,
1074 (int(eg_value(v)) * eg_value(w)) / 0x100);
1078 // scale_by_game_phase() interpolates between a middle game and an endgame score,
1079 // based on game phase. It also scales the return value by a ScaleFactor array.
1081 Value scale_by_game_phase(const Score& v, Phase ph, ScaleFactor sf) {
1083 assert(mg_value(v) > -VALUE_INFINITE && mg_value(v) < VALUE_INFINITE);
1084 assert(eg_value(v) > -VALUE_INFINITE && eg_value(v) < VALUE_INFINITE);
1085 assert(ph >= PHASE_ENDGAME && ph <= PHASE_MIDGAME);
1087 int ev = (eg_value(v) * int(sf)) / SCALE_FACTOR_NORMAL;
1088 int result = (mg_value(v) * int(ph) + ev * int(128 - ph)) / 128;
1089 return Value((result + GrainSize / 2) & ~(GrainSize - 1));
1093 // weight_option() computes the value of an evaluation weight, by combining
1094 // two UCI-configurable weights (midgame and endgame) with an internal weight.
1096 Score weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight) {
1098 // Scale option value from 100 to 256
1099 int mg = Options[mgOpt] * 256 / 100;
1100 int eg = Options[egOpt] * 256 / 100;
1102 return apply_weight(make_score(mg, eg), internalWeight);
1106 // init_safety() initizes the king safety evaluation, based on UCI
1107 // parameters. It is called from read_weights().
1109 void init_safety() {
1111 const Value MaxSlope = Value(30);
1112 const Value Peak = Value(1280);
1115 // First setup the base table
1116 for (int i = 0; i < 100; i++)
1118 t[i] = Value(int(0.4 * i * i));
1121 t[i] = std::min(t[i], t[i - 1] + MaxSlope);
1123 t[i] = std::min(t[i], Peak);
1126 // Then apply the weights and get the final KingDangerTable[] array
1127 for (Color c = WHITE; c <= BLACK; c++)
1128 for (int i = 0; i < 100; i++)
1129 KingDangerTable[c][i] = apply_weight(make_score(t[i], 0), Weights[KingDangerUs + c]);
1133 // A couple of little helpers used by tracing code, to_cp() converts a value to
1134 // a double in centipawns scale, trace_add() stores white and black scores.
1136 double to_cp(Value v) { return double(v) / double(PawnValueMidgame); }
1138 void trace_add(int idx, Score wScore, Score bScore) {
1140 TracedScores[WHITE][idx] = wScore;
1141 TracedScores[BLACK][idx] = bScore;
1144 // trace_row() is an helper function used by tracing code to register the
1145 // values of a single evaluation term.
1147 void trace_row(const char *name, int idx) {
1149 Score wScore = TracedScores[WHITE][idx];
1150 Score bScore = TracedScores[BLACK][idx];
1153 case PST: case IMBALANCE: case PAWN: case UNSTOPPABLE: case TOTAL:
1154 TraceStream << std::setw(20) << name << " | --- --- | --- --- | "
1155 << std::setw(6) << to_cp(mg_value(wScore)) << " "
1156 << std::setw(6) << to_cp(eg_value(wScore)) << " \n";
1159 TraceStream << std::setw(20) << name << " | " << std::noshowpos
1160 << std::setw(5) << to_cp(mg_value(wScore)) << " "
1161 << std::setw(5) << to_cp(eg_value(wScore)) << " | "
1162 << std::setw(5) << to_cp(mg_value(bScore)) << " "
1163 << std::setw(5) << to_cp(eg_value(bScore)) << " | "
1165 << std::setw(6) << to_cp(mg_value(wScore - bScore)) << " "
1166 << std::setw(6) << to_cp(eg_value(wScore - bScore)) << " \n";
1172 /// trace_evaluate() is like evaluate() but instead of a value returns a string
1173 /// suitable to be print on stdout with the detailed descriptions and values of
1174 /// each evaluation term. Used mainly for debugging.
1176 std::string trace_evaluate(const Position& pos) {
1181 TraceStream.str("");
1182 TraceStream << std::showpoint << std::showpos << std::fixed << std::setprecision(2);
1183 memset(TracedScores, 0, 2 * 16 * sizeof(Score));
1185 do_evaluate<true>(pos, margin);
1187 totals = TraceStream.str();
1188 TraceStream.str("");
1190 TraceStream << std::setw(21) << "Eval term " << "| White | Black | Total \n"
1191 << " | MG EG | MG EG | MG EG \n"
1192 << "---------------------+-------------+-------------+---------------\n";
1194 trace_row("Material, PST, Tempo", PST);
1195 trace_row("Material imbalance", IMBALANCE);
1196 trace_row("Pawns", PAWN);
1197 trace_row("Knights", KNIGHT);
1198 trace_row("Bishops", BISHOP);
1199 trace_row("Rooks", ROOK);
1200 trace_row("Queens", QUEEN);
1201 trace_row("Mobility", MOBILITY);
1202 trace_row("King safety", KING);
1203 trace_row("Threats", THREAT);
1204 trace_row("Passed pawns", PASSED);
1205 trace_row("Unstoppable pawns", UNSTOPPABLE);
1206 trace_row("Space", SPACE);
1208 TraceStream << "---------------------+-------------+-------------+---------------\n";
1209 trace_row("Total", TOTAL);
1210 TraceStream << totals;
1212 return TraceStream.str();