2 Stockfish, a UCI chess playing engine derived from Glaurung 2.1
3 Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
4 Copyright (C) 2008-2010 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/>.
35 #include "ucioption.h"
39 //// Local definitions
44 // Struct EvalInfo contains various information computed and collected
45 // by the evaluation functions.
48 // Pointer to pawn hash table entry
51 // attackedBy[color][piece type] is a bitboard representing all squares
52 // attacked by a given color and piece type, attackedBy[color][0] contains
53 // all squares attacked by the given color.
54 Bitboard attackedBy[2][8];
56 // kingZone[color] is the zone around the enemy king which is considered
57 // by the king safety evaluation. This consists of the squares directly
58 // adjacent to the king, and the three (or two, for a king on an edge file)
59 // squares two ranks in front of the king. For instance, if black's king
60 // is on g8, kingZone[WHITE] is a bitboard containing the squares f8, h8,
61 // f7, g7, h7, f6, g6 and h6.
64 // kingAttackersCount[color] is the number of pieces of the given color
65 // which attack a square in the kingZone of the enemy king.
66 int kingAttackersCount[2];
68 // kingAttackersWeight[color] is the sum of the "weight" of the pieces of the
69 // given color which attack a square in the kingZone of the enemy king. The
70 // weights of the individual piece types are given by the variables
71 // QueenAttackWeight, RookAttackWeight, BishopAttackWeight and
72 // KnightAttackWeight in evaluate.cpp
73 int kingAttackersWeight[2];
75 // kingAdjacentZoneAttacksCount[color] is the number of attacks to squares
76 // directly adjacent to the king of the given color. Pieces which attack
77 // more than one square are counted multiple times. For instance, if black's
78 // king is on g8 and there's a white knight on g5, this knight adds
79 // 2 to kingAdjacentZoneAttacksCount[BLACK].
80 int kingAdjacentZoneAttacksCount[2];
83 // Evaluation grain size, must be a power of 2
84 const int GrainSize = 8;
86 // Evaluation weights, initialized from UCI options
87 enum { Mobility, PawnStructure, PassedPawns, Space, KingDangerUs, KingDangerThem };
91 #define S(mg, eg) make_score(mg, eg)
93 // Internal evaluation weights. These are applied on top of the evaluation
94 // weights read from UCI parameters. The purpose is to be able to change
95 // the evaluation weights while keeping the default values of the UCI
96 // parameters at 100, which looks prettier.
98 // Values modified by Joona Kiiski
99 const Score WeightsInternal[] = {
100 S(248, 271), S(233, 201), S(252, 259), S(46, 0), S(247, 0), S(259, 0)
103 // MobilityBonus[PieceType][attacked] contains mobility bonuses for middle and
104 // end game, indexed by piece type and number of attacked squares not occupied
105 // by friendly pieces.
106 const Score MobilityBonus[][32] = {
108 { S(-38,-33), S(-25,-23), S(-12,-13), S( 0, -3), S(12, 7), S(25, 17), // Knights
109 S( 31, 22), S( 38, 27), S( 38, 27) },
110 { S(-25,-30), S(-11,-16), S( 3, -2), S(17, 12), S(31, 26), S(45, 40), // Bishops
111 S( 57, 52), S( 65, 60), S( 71, 65), S(74, 69), S(76, 71), S(78, 73),
112 S( 79, 74), S( 80, 75), S( 81, 76), S(81, 76) },
113 { S(-20,-36), S(-14,-19), S( -8, -3), S(-2, 13), S( 4, 29), S(10, 46), // Rooks
114 S( 14, 62), S( 19, 79), S( 23, 95), S(26,106), S(27,111), S(28,114),
115 S( 29,116), S( 30,117), S( 31,118), S(32,118) },
116 { S(-10,-18), S( -8,-13), S( -6, -7), S(-3, -2), S(-1, 3), S( 1, 8), // Queens
117 S( 3, 13), S( 5, 19), S( 8, 23), S(10, 27), S(12, 32), S(15, 34),
118 S( 16, 35), S( 17, 35), S( 18, 35), S(20, 35), S(20, 35), S(20, 35),
119 S( 20, 35), S( 20, 35), S( 20, 35), S(20, 35), S(20, 35), S(20, 35),
120 S( 20, 35), S( 20, 35), S( 20, 35), S(20, 35), S(20, 35), S(20, 35),
121 S( 20, 35), S( 20, 35) }
124 // OutpostBonus[PieceType][Square] contains outpost bonuses of knights and
125 // bishops, indexed by piece type and square (from white's point of view).
126 const Value OutpostBonus[][64] = {
129 V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // Knights
130 V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0),
131 V(0), V(0), V(4), V(8), V(8), V(4), V(0), V(0),
132 V(0), V(4),V(17),V(26),V(26),V(17), V(4), V(0),
133 V(0), V(8),V(26),V(35),V(35),V(26), V(8), V(0),
134 V(0), V(4),V(17),V(17),V(17),V(17), V(4), V(0) },
136 V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // Bishops
137 V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0),
138 V(0), V(0), V(5), V(5), V(5), V(5), V(0), V(0),
139 V(0), V(5),V(10),V(10),V(10),V(10), V(5), V(0),
140 V(0),V(10),V(21),V(21),V(21),V(21),V(10), V(0),
141 V(0), V(5), V(8), V(8), V(8), V(8), V(5), V(0) }
144 // ThreatBonus[attacking][attacked] contains threat bonuses according to
145 // which piece type attacks which one.
146 const Score ThreatBonus[][8] = {
148 { S(0, 0), S( 7, 39), S( 0, 0), S(24, 49), S(41,100), S(41,100) }, // KNIGHT
149 { S(0, 0), S( 7, 39), S(24, 49), S( 0, 0), S(41,100), S(41,100) }, // BISHOP
150 { S(0, 0), S(-1, 29), S(15, 49), S(15, 49), S( 0, 0), S(24, 49) }, // ROOK
151 { S(0, 0), S(15, 39), S(15, 39), S(15, 39), S(15, 39), S( 0, 0) } // QUEEN
154 // ThreatedByPawnPenalty[PieceType] contains a penalty according to which
155 // piece type is attacked by an enemy pawn.
156 const Score ThreatedByPawnPenalty[] = {
157 S(0, 0), S(0, 0), S(56, 70), S(56, 70), S(76, 99), S(86, 118)
162 // Rooks and queens on the 7th rank (modified by Joona Kiiski)
163 const Score RookOn7thBonus = make_score(47, 98);
164 const Score QueenOn7thBonus = make_score(27, 54);
166 // Rooks on open files (modified by Joona Kiiski)
167 const Score RookOpenFileBonus = make_score(43, 43);
168 const Score RookHalfOpenFileBonus = make_score(19, 19);
170 // Penalty for rooks trapped inside a friendly king which has lost the
172 const Value TrappedRookPenalty = Value(180);
174 // Penalty for a bishop on a1/h1 (a8/h8 for black) which is trapped by
175 // a friendly pawn on b2/g2 (b7/g7 for black). This can obviously only
176 // happen in Chess960 games.
177 const Score TrappedBishopA1H1Penalty = make_score(100, 100);
179 // The SpaceMask[Color] contains the area of the board which is considered
180 // by the space evaluation. In the middle game, each side is given a bonus
181 // based on how many squares inside this area are safe and available for
182 // friendly minor pieces.
183 const Bitboard SpaceMask[] = {
184 (1ULL << SQ_C2) | (1ULL << SQ_D2) | (1ULL << SQ_E2) | (1ULL << SQ_F2) |
185 (1ULL << SQ_C3) | (1ULL << SQ_D3) | (1ULL << SQ_E3) | (1ULL << SQ_F3) |
186 (1ULL << SQ_C4) | (1ULL << SQ_D4) | (1ULL << SQ_E4) | (1ULL << SQ_F4),
187 (1ULL << SQ_C7) | (1ULL << SQ_D7) | (1ULL << SQ_E7) | (1ULL << SQ_F7) |
188 (1ULL << SQ_C6) | (1ULL << SQ_D6) | (1ULL << SQ_E6) | (1ULL << SQ_F6) |
189 (1ULL << SQ_C5) | (1ULL << SQ_D5) | (1ULL << SQ_E5) | (1ULL << SQ_F5)
192 // King danger constants and variables. The king danger scores are taken
193 // from the KingDangerTable[]. Various little "meta-bonuses" measuring
194 // the strength of the enemy attack are added up into an integer, which
195 // is used as an index to KingDangerTable[].
197 // KingAttackWeights[PieceType] contains king attack weights by piece type
198 const int KingAttackWeights[] = { 0, 0, 2, 2, 3, 5 };
200 // Bonuses for enemy's safe checks
201 const int QueenContactCheckBonus = 6;
202 const int RookContactCheckBonus = 4;
203 const int QueenCheckBonus = 3;
204 const int RookCheckBonus = 2;
205 const int BishopCheckBonus = 1;
206 const int KnightCheckBonus = 1;
208 // InitKingDanger[Square] contains penalties based on the position of the
209 // defending king, indexed by king's square (from white's point of view).
210 const int InitKingDanger[] = {
211 2, 0, 2, 5, 5, 2, 0, 2,
212 2, 2, 4, 8, 8, 4, 2, 2,
213 7, 10, 12, 12, 12, 12, 10, 7,
214 15, 15, 15, 15, 15, 15, 15, 15,
215 15, 15, 15, 15, 15, 15, 15, 15,
216 15, 15, 15, 15, 15, 15, 15, 15,
217 15, 15, 15, 15, 15, 15, 15, 15,
218 15, 15, 15, 15, 15, 15, 15, 15
221 // KingDangerTable[Color][attackUnits] contains the actual king danger
222 // weighted scores, indexed by color and by a calculated integer number.
223 Score KingDangerTable[2][128];
225 // TracedTerms[Color][PieceType || TracedType] contains a breakdown of the
226 // evaluation terms, used when tracing.
227 Score TracedTerms[2][16];
228 std::stringstream TraceStream;
231 PST = 8, IMBALANCE = 9, MOBILITY = 10, THREAT = 11,
232 PASSED = 12, UNSTOPPABLE = 13, SPACE = 14, TOTAL = 15
235 // Function prototypes
236 template<bool HasPopCnt, bool Trace>
237 Value do_evaluate(const Position& pos, Value& margin);
239 template<Color Us, bool HasPopCnt>
240 void init_eval_info(const Position& pos, EvalInfo& ei);
242 template<Color Us, bool HasPopCnt, bool Trace>
243 Score evaluate_pieces_of_color(const Position& pos, EvalInfo& ei, Score& mobility);
245 template<Color Us, bool HasPopCnt, bool Trace>
246 Score evaluate_king(const Position& pos, EvalInfo& ei, Value margins[]);
249 Score evaluate_threats(const Position& pos, EvalInfo& ei);
251 template<Color Us, bool HasPopCnt>
252 int evaluate_space(const Position& pos, EvalInfo& ei);
255 Score evaluate_passed_pawns(const Position& pos, EvalInfo& ei);
257 template<bool HasPopCnt>
258 Score evaluate_unstoppable_pawns(const Position& pos, EvalInfo& ei);
260 inline Score apply_weight(Score v, Score weight);
261 Value scale_by_game_phase(const Score& v, Phase ph, ScaleFactor sf);
262 Score weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight);
267 /// evaluate() is the main evaluation function. It always computes two
268 /// values, an endgame score and a middle game score, and interpolates
269 /// between them based on the remaining material.
270 Value evaluate(const Position& pos, Value& margin) {
272 return CpuHasPOPCNT ? do_evaluate<true, false>(pos, margin)
273 : do_evaluate<false, false>(pos, margin);
278 double to_cp(Value v) { return double(v) / double(PawnValueMidgame); }
280 void trace_add(int idx, Score term_w, Score term_b = Score(0)) {
282 TracedTerms[WHITE][idx] = term_w;
283 TracedTerms[BLACK][idx] = term_b;
286 template<bool HasPopCnt, bool Trace>
287 Value do_evaluate(const Position& pos, Value& margin) {
291 Score mobilityWhite, mobilityBlack;
294 assert(pos.thread() >= 0 && pos.thread() < MAX_THREADS);
295 assert(!pos.in_check());
297 // Initialize value by reading the incrementally updated scores included
298 // in the position object (material + piece square tables).
299 Score bonus = pos.value();
301 // margins[] store the uncertainty estimation of position's evaluation
302 // that typically is used by the search for pruning decisions.
303 margins[WHITE] = margins[BLACK] = VALUE_ZERO;
305 // Probe the material hash table
306 MaterialInfo* mi = Threads[pos.thread()].materialTable.get_material_info(pos);
307 bonus += mi->material_value();
309 // If we have a specialized evaluation function for the current material
310 // configuration, call it and return.
311 if (mi->specialized_eval_exists())
314 return mi->evaluate(pos);
317 // Probe the pawn hash table
318 ei.pi = Threads[pos.thread()].pawnTable.get_pawn_info(pos);
319 bonus += apply_weight(ei.pi->pawns_value(), Weights[PawnStructure]);
321 // Initialize attack and king safety bitboards
322 init_eval_info<WHITE, HasPopCnt>(pos, ei);
323 init_eval_info<BLACK, HasPopCnt>(pos, ei);
325 // Evaluate pieces and mobility
326 bonus += evaluate_pieces_of_color<WHITE, HasPopCnt, Trace>(pos, ei, mobilityWhite)
327 - evaluate_pieces_of_color<BLACK, HasPopCnt, Trace>(pos, ei, mobilityBlack);
329 bonus += apply_weight(mobilityWhite - mobilityBlack, Weights[Mobility]);
331 // Evaluate kings after all other pieces because we need complete attack
332 // information when computing the king safety evaluation.
333 bonus += evaluate_king<WHITE, HasPopCnt, Trace>(pos, ei, margins)
334 - evaluate_king<BLACK, HasPopCnt, Trace>(pos, ei, margins);
336 // Evaluate tactical threats, we need full attack information including king
337 bonus += evaluate_threats<WHITE>(pos, ei)
338 - evaluate_threats<BLACK>(pos, ei);
340 // Evaluate passed pawns, we need full attack information including king
341 bonus += evaluate_passed_pawns<WHITE>(pos, ei)
342 - evaluate_passed_pawns<BLACK>(pos, ei);
344 // If one side has only a king, check whether exists any unstoppable passed pawn
345 if (!pos.non_pawn_material(WHITE) || !pos.non_pawn_material(BLACK))
346 bonus += evaluate_unstoppable_pawns<HasPopCnt>(pos, ei);
348 // Evaluate space for both sides, only in middle-game.
349 if (mi->space_weight())
351 int s_w = evaluate_space<WHITE, HasPopCnt>(pos, ei);
352 int s_b = evaluate_space<BLACK, HasPopCnt>(pos, ei);
353 bonus += apply_weight(make_score((s_w - s_b) * mi->space_weight(), 0), Weights[Space]);
356 trace_add(SPACE, apply_weight(make_score(s_w * mi->space_weight(), make_score(0, 0)), Weights[Space]),
357 apply_weight(make_score(s_b * mi->space_weight(), make_score(0, 0)), Weights[Space]));
360 // Scale winning side if position is more drawish that what it appears
361 ScaleFactor sf = eg_value(bonus) > VALUE_DRAW ? mi->scale_factor(pos, WHITE)
362 : mi->scale_factor(pos, BLACK);
363 Phase phase = mi->game_phase();
365 // If we don't already have an unusual scale factor, check for opposite
366 // colored bishop endgames, and use a lower scale for those.
367 if ( phase < PHASE_MIDGAME
368 && pos.opposite_colored_bishops()
369 && sf == SCALE_FACTOR_NORMAL)
371 // Only the two bishops ?
372 if ( pos.non_pawn_material(WHITE) == BishopValueMidgame
373 && pos.non_pawn_material(BLACK) == BishopValueMidgame)
375 // Check for KBP vs KB with only a single pawn that is almost
376 // certainly a draw or at least two pawns.
377 bool one_pawn = (pos.piece_count(WHITE, PAWN) + pos.piece_count(BLACK, PAWN) == 1);
378 sf = one_pawn ? ScaleFactor(8) : ScaleFactor(32);
381 // Endgame with opposite-colored bishops, but also other pieces. Still
382 // a bit drawish, but not as drawish as with only the two bishops.
383 sf = ScaleFactor(50);
386 // Interpolate between the middle game and the endgame score
387 margin = margins[pos.side_to_move()];
388 Value v = scale_by_game_phase(bonus, phase, sf);
392 trace_add(PST, pos.value());
393 trace_add(IMBALANCE, mi->material_value());
394 trace_add(PAWN, apply_weight(ei.pi->pawns_value(), Weights[PawnStructure]));
395 trace_add(MOBILITY, apply_weight(mobilityWhite, Weights[Mobility]), apply_weight(mobilityBlack, Weights[Mobility]));
396 trace_add(THREAT, evaluate_threats<WHITE>(pos, ei), evaluate_threats<BLACK>(pos, ei));
397 trace_add(PASSED, evaluate_passed_pawns<WHITE>(pos, ei), evaluate_passed_pawns<BLACK>(pos, ei));
398 trace_add(UNSTOPPABLE, evaluate_unstoppable_pawns<HasPopCnt>(pos, ei));
399 trace_add(TOTAL, bonus);
400 TraceStream << "\nUncertainty margin: White: " << to_cp(margins[WHITE])
401 << ", Black: " << to_cp(margins[BLACK])
402 << "\nScaling: " << std::noshowpos
403 << std::setw(6) << 100.0 * phase/128.0 << "% MG, "
404 << std::setw(6) << 100.0 * (1.0 - phase/128.0) << "% * "
405 << std::setw(6) << (100.0 * sf) / SCALE_FACTOR_NORMAL << "% EG.\n"
406 << "Total evaluation: " << to_cp(v);
409 return pos.side_to_move() == WHITE ? v : -v;
415 /// read_weights() reads evaluation weights from the corresponding UCI parameters
417 void read_evaluation_uci_options(Color us) {
419 // King safety is asymmetrical. Our king danger level is weighted by
420 // "Cowardice" UCI parameter, instead the opponent one by "Aggressiveness".
421 const int kingDangerUs = (us == WHITE ? KingDangerUs : KingDangerThem);
422 const int kingDangerThem = (us == WHITE ? KingDangerThem : KingDangerUs);
424 Weights[Mobility] = weight_option("Mobility (Middle Game)", "Mobility (Endgame)", WeightsInternal[Mobility]);
425 Weights[PawnStructure] = weight_option("Pawn Structure (Middle Game)", "Pawn Structure (Endgame)", WeightsInternal[PawnStructure]);
426 Weights[PassedPawns] = weight_option("Passed Pawns (Middle Game)", "Passed Pawns (Endgame)", WeightsInternal[PassedPawns]);
427 Weights[Space] = weight_option("Space", "Space", WeightsInternal[Space]);
428 Weights[kingDangerUs] = weight_option("Cowardice", "Cowardice", WeightsInternal[KingDangerUs]);
429 Weights[kingDangerThem] = weight_option("Aggressiveness", "Aggressiveness", WeightsInternal[KingDangerThem]);
431 // If running in analysis mode, make sure we use symmetrical king safety. We do this
432 // by replacing both Weights[kingDangerUs] and Weights[kingDangerThem] by their average.
433 if (Options["UCI_AnalyseMode"].value<bool>())
434 Weights[kingDangerUs] = Weights[kingDangerThem] = (Weights[kingDangerUs] + Weights[kingDangerThem]) / 2;
442 // init_eval_info() initializes king bitboards for given color adding
443 // pawn attacks. To be done at the beginning of the evaluation.
445 template<Color Us, bool HasPopCnt>
446 void init_eval_info(const Position& pos, EvalInfo& ei) {
448 const BitCountType Max15 = HasPopCnt ? CNT_POPCNT : CpuIs64Bit ? CNT64_MAX15 : CNT32_MAX15;
449 const Color Them = (Us == WHITE ? BLACK : WHITE);
451 Bitboard b = ei.attackedBy[Them][KING] = pos.attacks_from<KING>(pos.king_square(Them));
452 ei.attackedBy[Us][PAWN] = ei.pi->pawn_attacks(Us);
454 // Init king safety tables only if we are going to use them
455 if ( pos.piece_count(Us, QUEEN)
456 && pos.non_pawn_material(Us) >= QueenValueMidgame + RookValueMidgame)
458 ei.kingZone[Us] = (b | (Us == WHITE ? b >> 8 : b << 8));
459 b &= ei.attackedBy[Us][PAWN];
460 ei.kingAttackersCount[Us] = b ? count_1s<Max15>(b) / 2 : 0;
461 ei.kingAdjacentZoneAttacksCount[Us] = ei.kingAttackersWeight[Us] = 0;
463 ei.kingZone[Us] = ei.kingAttackersCount[Us] = 0;
467 // evaluate_outposts() evaluates bishop and knight outposts squares
469 template<PieceType Piece, Color Us>
470 Score evaluate_outposts(const Position& pos, EvalInfo& ei, Square s) {
472 const Color Them = (Us == WHITE ? BLACK : WHITE);
474 assert (Piece == BISHOP || Piece == KNIGHT);
476 // Initial bonus based on square
477 Value bonus = OutpostBonus[Piece == BISHOP][relative_square(Us, s)];
479 // Increase bonus if supported by pawn, especially if the opponent has
480 // no minor piece which can exchange the outpost piece.
481 if (bonus && bit_is_set(ei.attackedBy[Us][PAWN], s))
483 if ( pos.pieces(KNIGHT, Them) == EmptyBoardBB
484 && (SquaresByColorBB[square_color(s)] & pos.pieces(BISHOP, Them)) == EmptyBoardBB)
485 bonus += bonus + bonus / 2;
489 return make_score(bonus, bonus);
493 // evaluate_pieces<>() assigns bonuses and penalties to the pieces of a given color
495 template<PieceType Piece, Color Us, bool HasPopCnt, bool Trace>
496 Score evaluate_pieces(const Position& pos, EvalInfo& ei, Score& mobility, Bitboard mobilityArea) {
502 Score bonus = SCORE_ZERO;
504 const BitCountType Full = HasPopCnt ? CNT_POPCNT : CpuIs64Bit ? CNT64 : CNT32;
505 const BitCountType Max15 = HasPopCnt ? CNT_POPCNT : CpuIs64Bit ? CNT64_MAX15 : CNT32_MAX15;
506 const Color Them = (Us == WHITE ? BLACK : WHITE);
507 const Square* ptr = pos.piece_list_begin(Us, Piece);
509 ei.attackedBy[Us][Piece] = EmptyBoardBB;
511 while ((s = *ptr++) != SQ_NONE)
513 // Find attacked squares, including x-ray attacks for bishops and rooks
514 if (Piece == KNIGHT || Piece == QUEEN)
515 b = pos.attacks_from<Piece>(s);
516 else if (Piece == BISHOP)
517 b = bishop_attacks_bb(s, pos.occupied_squares() & ~pos.pieces(QUEEN, Us));
518 else if (Piece == ROOK)
519 b = rook_attacks_bb(s, pos.occupied_squares() & ~pos.pieces(ROOK, QUEEN, Us));
523 // Update attack info
524 ei.attackedBy[Us][Piece] |= b;
527 if (b & ei.kingZone[Us])
529 ei.kingAttackersCount[Us]++;
530 ei.kingAttackersWeight[Us] += KingAttackWeights[Piece];
531 Bitboard bb = (b & ei.attackedBy[Them][KING]);
533 ei.kingAdjacentZoneAttacksCount[Us] += count_1s<Max15>(bb);
537 mob = (Piece != QUEEN ? count_1s<Max15>(b & mobilityArea)
538 : count_1s<Full >(b & mobilityArea));
540 mobility += MobilityBonus[Piece][mob];
542 // Decrease score if we are attacked by an enemy pawn. Remaining part
543 // of threat evaluation must be done later when we have full attack info.
544 if (bit_is_set(ei.attackedBy[Them][PAWN], s))
545 bonus -= ThreatedByPawnPenalty[Piece];
547 // Bishop and knight outposts squares
548 if ((Piece == BISHOP || Piece == KNIGHT) && pos.square_is_weak(s, Us))
549 bonus += evaluate_outposts<Piece, Us>(pos, ei, s);
551 // Queen or rook on 7th rank
552 if ( (Piece == ROOK || Piece == QUEEN)
553 && relative_rank(Us, s) == RANK_7
554 && relative_rank(Us, pos.king_square(Them)) == RANK_8)
556 bonus += (Piece == ROOK ? RookOn7thBonus : QueenOn7thBonus);
559 // Special extra evaluation for bishops
560 if (Piece == BISHOP && pos.is_chess960())
562 // An important Chess960 pattern: A cornered bishop blocked by
563 // a friendly pawn diagonally in front of it is a very serious
564 // problem, especially when that pawn is also blocked.
565 if (s == relative_square(Us, SQ_A1) || s == relative_square(Us, SQ_H1))
567 Square d = pawn_push(Us) + (square_file(s) == FILE_A ? DELTA_E : DELTA_W);
568 if (pos.piece_on(s + d) == make_piece(Us, PAWN))
570 if (!pos.square_is_empty(s + d + pawn_push(Us)))
571 bonus -= 2*TrappedBishopA1H1Penalty;
572 else if (pos.piece_on(s + 2*d) == make_piece(Us, PAWN))
573 bonus -= TrappedBishopA1H1Penalty;
575 bonus -= TrappedBishopA1H1Penalty / 2;
580 // Special extra evaluation for rooks
583 // Open and half-open files
585 if (ei.pi->file_is_half_open(Us, f))
587 if (ei.pi->file_is_half_open(Them, f))
588 bonus += RookOpenFileBonus;
590 bonus += RookHalfOpenFileBonus;
593 // Penalize rooks which are trapped inside a king. Penalize more if
594 // king has lost right to castle.
595 if (mob > 6 || ei.pi->file_is_half_open(Us, f))
598 ksq = pos.king_square(Us);
600 if ( square_file(ksq) >= FILE_E
601 && square_file(s) > square_file(ksq)
602 && (relative_rank(Us, ksq) == RANK_1 || square_rank(ksq) == square_rank(s)))
604 // Is there a half-open file between the king and the edge of the board?
605 if (!ei.pi->has_open_file_to_right(Us, square_file(ksq)))
606 bonus -= make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2
607 : (TrappedRookPenalty - mob * 16), 0);
609 else if ( square_file(ksq) <= FILE_D
610 && square_file(s) < square_file(ksq)
611 && (relative_rank(Us, ksq) == RANK_1 || square_rank(ksq) == square_rank(s)))
613 // Is there a half-open file between the king and the edge of the board?
614 if (!ei.pi->has_open_file_to_left(Us, square_file(ksq)))
615 bonus -= make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2
616 : (TrappedRookPenalty - mob * 16), 0);
622 TracedTerms[Us][Piece] = bonus;
628 // evaluate_threats<>() assigns bonuses according to the type of attacking piece
629 // and the type of attacked one.
632 Score evaluate_threats(const Position& pos, EvalInfo& ei) {
634 const Color Them = (Us == WHITE ? BLACK : WHITE);
637 Score bonus = SCORE_ZERO;
639 // Enemy pieces not defended by a pawn and under our attack
640 Bitboard weakEnemies = pos.pieces_of_color(Them)
641 & ~ei.attackedBy[Them][PAWN]
642 & ei.attackedBy[Us][0];
646 // Add bonus according to type of attacked enemy piece and to the
647 // type of attacking piece, from knights to queens. Kings are not
648 // considered because are already handled in king evaluation.
649 for (PieceType pt1 = KNIGHT; pt1 < KING; pt1++)
651 b = ei.attackedBy[Us][pt1] & weakEnemies;
653 for (PieceType pt2 = PAWN; pt2 < KING; pt2++)
654 if (b & pos.pieces(pt2))
655 bonus += ThreatBonus[pt1][pt2];
661 // evaluate_pieces_of_color<>() assigns bonuses and penalties to all the
662 // pieces of a given color.
664 template<Color Us, bool HasPopCnt, bool Trace>
665 Score evaluate_pieces_of_color(const Position& pos, EvalInfo& ei, Score& mobility) {
667 const Color Them = (Us == WHITE ? BLACK : WHITE);
669 Score bonus = mobility = SCORE_ZERO;
671 // Do not include in mobility squares protected by enemy pawns or occupied by our pieces
672 const Bitboard mobilityArea = ~(ei.attackedBy[Them][PAWN] | pos.pieces_of_color(Us));
674 bonus += evaluate_pieces<KNIGHT, Us, HasPopCnt, Trace>(pos, ei, mobility, mobilityArea);
675 bonus += evaluate_pieces<BISHOP, Us, HasPopCnt, Trace>(pos, ei, mobility, mobilityArea);
676 bonus += evaluate_pieces<ROOK, Us, HasPopCnt, Trace>(pos, ei, mobility, mobilityArea);
677 bonus += evaluate_pieces<QUEEN, Us, HasPopCnt, Trace>(pos, ei, mobility, mobilityArea);
679 // Sum up all attacked squares
680 ei.attackedBy[Us][0] = ei.attackedBy[Us][PAWN] | ei.attackedBy[Us][KNIGHT]
681 | ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK]
682 | ei.attackedBy[Us][QUEEN] | ei.attackedBy[Us][KING];
687 // evaluate_king<>() assigns bonuses and penalties to a king of a given color
689 template<Color Us, bool HasPopCnt, bool Trace>
690 Score evaluate_king(const Position& pos, EvalInfo& ei, Value margins[]) {
692 const BitCountType Max15 = HasPopCnt ? CNT_POPCNT : CpuIs64Bit ? CNT64_MAX15 : CNT32_MAX15;
693 const Color Them = (Us == WHITE ? BLACK : WHITE);
695 Bitboard undefended, b, b1, b2, safe;
697 const Square ksq = pos.king_square(Us);
700 Score bonus = ei.pi->king_shelter<Us>(pos, ksq);
702 // King safety. This is quite complicated, and is almost certainly far
703 // from optimally tuned.
704 if ( ei.kingAttackersCount[Them] >= 2
705 && ei.kingAdjacentZoneAttacksCount[Them])
707 // Find the attacked squares around the king which has no defenders
708 // apart from the king itself
709 undefended = ei.attackedBy[Them][0] & ei.attackedBy[Us][KING];
710 undefended &= ~( ei.attackedBy[Us][PAWN] | ei.attackedBy[Us][KNIGHT]
711 | ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK]
712 | ei.attackedBy[Us][QUEEN]);
714 // Initialize the 'attackUnits' variable, which is used later on as an
715 // index to the KingDangerTable[] array. The initial value is based on
716 // the number and types of the enemy's attacking pieces, the number of
717 // attacked and undefended squares around our king, the square of the
718 // king, and the quality of the pawn shelter.
719 attackUnits = Min(25, (ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) / 2)
720 + 3 * (ei.kingAdjacentZoneAttacksCount[Them] + count_1s<Max15>(undefended))
721 + InitKingDanger[relative_square(Us, ksq)]
722 - mg_value(ei.pi->king_shelter<Us>(pos, ksq)) / 32;
724 // Analyse enemy's safe queen contact checks. First find undefended
725 // squares around the king attacked by enemy queen...
726 b = undefended & ei.attackedBy[Them][QUEEN] & ~pos.pieces_of_color(Them);
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][ROOK]);
733 attackUnits += QueenContactCheckBonus
735 * (Them == pos.side_to_move() ? 2 : 1);
738 // Analyse enemy's safe rook contact checks. First find undefended
739 // squares around the king attacked by enemy rooks...
740 b = undefended & ei.attackedBy[Them][ROOK] & ~pos.pieces_of_color(Them);
742 // Consider only squares where the enemy rook gives check
743 b &= RookPseudoAttacks[ksq];
747 // ...then remove squares not supported by another enemy piece
748 b &= ( ei.attackedBy[Them][PAWN] | ei.attackedBy[Them][KNIGHT]
749 | ei.attackedBy[Them][BISHOP] | ei.attackedBy[Them][QUEEN]);
751 attackUnits += RookContactCheckBonus
753 * (Them == pos.side_to_move() ? 2 : 1);
756 // Analyse enemy's safe distance checks for sliders and knights
757 safe = ~(pos.pieces_of_color(Them) | ei.attackedBy[Us][0]);
759 b1 = pos.attacks_from<ROOK>(ksq) & safe;
760 b2 = pos.attacks_from<BISHOP>(ksq) & safe;
762 // Enemy queen safe checks
763 b = (b1 | b2) & ei.attackedBy[Them][QUEEN];
765 attackUnits += QueenCheckBonus * count_1s<Max15>(b);
767 // Enemy rooks safe checks
768 b = b1 & ei.attackedBy[Them][ROOK];
770 attackUnits += RookCheckBonus * count_1s<Max15>(b);
772 // Enemy bishops safe checks
773 b = b2 & ei.attackedBy[Them][BISHOP];
775 attackUnits += BishopCheckBonus * count_1s<Max15>(b);
777 // Enemy knights safe checks
778 b = pos.attacks_from<KNIGHT>(ksq) & ei.attackedBy[Them][KNIGHT] & safe;
780 attackUnits += KnightCheckBonus * count_1s<Max15>(b);
782 // To index KingDangerTable[] attackUnits must be in [0, 99] range
783 attackUnits = Min(99, Max(0, attackUnits));
785 // Finally, extract the king danger score from the KingDangerTable[]
786 // array and subtract the score from evaluation. Set also margins[]
787 // value that will be used for pruning because this value can sometimes
788 // be very big, and so capturing a single attacking piece can therefore
789 // result in a score change far bigger than the value of the captured piece.
790 bonus -= KingDangerTable[Us][attackUnits];
791 margins[Us] += mg_value(KingDangerTable[Us][attackUnits]);
795 TracedTerms[Us][KING] = bonus;
801 // evaluate_passed_pawns<>() evaluates the passed pawns of the given color
804 Score evaluate_passed_pawns(const Position& pos, EvalInfo& ei) {
806 const Color Them = (Us == WHITE ? BLACK : WHITE);
808 Score bonus = SCORE_ZERO;
809 Bitboard squaresToQueen, defendedSquares, unsafeSquares, supportingPawns;
810 Bitboard b = ei.pi->passed_pawns(Us);
816 Square s = pop_1st_bit(&b);
818 assert(pos.pawn_is_passed(Us, s));
820 int r = int(relative_rank(Us, s) - RANK_2);
821 int rr = r * (r - 1);
823 // Base bonus based on rank
824 Value mbonus = Value(20 * rr);
825 Value ebonus = Value(10 * (rr + r + 1));
829 Square blockSq = s + pawn_push(Us);
831 // Adjust bonus based on kings proximity
832 ebonus -= Value(square_distance(pos.king_square(Us), blockSq) * 3 * rr);
833 ebonus -= Value(square_distance(pos.king_square(Us), blockSq + pawn_push(Us)) * rr);
834 ebonus += Value(square_distance(pos.king_square(Them), blockSq) * 6 * rr);
836 // If the pawn is free to advance, increase bonus
837 if (pos.square_is_empty(blockSq))
839 squaresToQueen = squares_in_front_of(Us, s);
840 defendedSquares = squaresToQueen & ei.attackedBy[Us][0];
842 // If there is an enemy rook or queen attacking the pawn from behind,
843 // add all X-ray attacks by the rook or queen. Otherwise consider only
844 // the squares in the pawn's path attacked or occupied by the enemy.
845 if ( (squares_in_front_of(Them, s) & pos.pieces(ROOK, QUEEN, Them))
846 && (squares_in_front_of(Them, s) & pos.pieces(ROOK, QUEEN, Them) & pos.attacks_from<ROOK>(s)))
847 unsafeSquares = squaresToQueen;
849 unsafeSquares = squaresToQueen & (ei.attackedBy[Them][0] | pos.pieces_of_color(Them));
851 // If there aren't enemy attacks or pieces along the path to queen give
852 // huge bonus. Even bigger if we protect the pawn's path.
854 ebonus += Value(rr * (squaresToQueen == defendedSquares ? 17 : 15));
856 // OK, there are enemy attacks or pieces (but not pawns). Are those
857 // squares which are attacked by the enemy also attacked by us ?
858 // If yes, big bonus (but smaller than when there are no enemy attacks),
859 // if no, somewhat smaller bonus.
860 ebonus += Value(rr * ((unsafeSquares & defendedSquares) == unsafeSquares ? 13 : 8));
862 // At last, add a small bonus when there are no *friendly* pieces
863 // in the pawn's path.
864 if (!(squaresToQueen & pos.pieces_of_color(Us)))
869 // Increase the bonus if the passed pawn is supported by a friendly pawn
870 // on the same rank and a bit smaller if it's on the previous rank.
871 supportingPawns = pos.pieces(PAWN, Us) & neighboring_files_bb(s);
872 if (supportingPawns & rank_bb(s))
873 ebonus += Value(r * 20);
874 else if (supportingPawns & rank_bb(s - pawn_push(Us)))
875 ebonus += Value(r * 12);
877 // Rook pawns are a special case: They are sometimes worse, and
878 // sometimes better than other passed pawns. It is difficult to find
879 // good rules for determining whether they are good or bad. For now,
880 // we try the following: Increase the value for rook pawns if the
881 // other side has no pieces apart from a knight, and decrease the
882 // value if the other side has a rook or queen.
883 if (square_file(s) == FILE_A || square_file(s) == FILE_H)
885 if (pos.non_pawn_material(Them) <= KnightValueMidgame)
886 ebonus += ebonus / 4;
887 else if (pos.pieces(ROOK, QUEEN, Them))
888 ebonus -= ebonus / 4;
890 bonus += make_score(mbonus, ebonus);
894 // Add the scores to the middle game and endgame eval
895 return apply_weight(bonus, Weights[PassedPawns]);
899 // evaluate_unstoppable_pawns() evaluates the unstoppable passed pawns for both sides
901 template<bool HasPopCnt>
902 Score evaluate_unstoppable_pawns(const Position& pos, EvalInfo& ei) {
904 const BitCountType Max15 = HasPopCnt ? CNT_POPCNT : CpuIs64Bit ? CNT64_MAX15 : CNT32_MAX15;
906 Bitboard b1, b2, queeningPath, candidates, supBB, sacBB;
907 Square s1, s2, queeningSquare, supSq, sacSq;
908 Color c, winnerSide, loserSide;
909 bool pathDefended, opposed;
910 int pliesToGo, movesToGo, oppMovesToGo;
911 int pliesToQueen[] = { 256, 256 };
913 // Step 1. Hunt for unstoppable pawns. If we find at least one, record how many plies
914 // are required for promotion
915 for (c = WHITE; c <= BLACK; c++)
917 // Skip if other side has non-pawn pieces
918 if (pos.non_pawn_material(opposite_color(c)))
921 b1 = ei.pi->passed_pawns(c);
925 s1 = pop_1st_bit(&b1);
926 queeningSquare = relative_square(c, make_square(square_file(s1), RANK_8));
927 queeningPath = squares_in_front_of(c, s1);
929 // Compute plies from queening and check direct advancement
930 movesToGo = rank_distance(s1, queeningSquare) - int(relative_rank(c, s1) == RANK_2);
931 oppMovesToGo = square_distance(pos.king_square(opposite_color(c)), queeningSquare) - int(c != pos.side_to_move());
932 pathDefended = ((ei.attackedBy[c][0] & queeningPath) == queeningPath);
934 if (movesToGo >= oppMovesToGo && !pathDefended)
937 // Opponent king cannot block because path is defended and position
938 // is not in check. So only friendly pieces can be blockers.
939 assert(!pos.in_check());
940 assert(queeningPath & pos.occupied_squares() == queeningPath & pos.pieces_of_color(c));
942 // Add moves needed to free the path from friendly pieces and retest condition
943 movesToGo += count_1s<Max15>(queeningPath & pos.pieces_of_color(c));
945 if (movesToGo >= oppMovesToGo && !pathDefended)
948 pliesToGo = 2 * movesToGo - int(c == pos.side_to_move());
950 if (pliesToGo < pliesToQueen[c])
951 pliesToQueen[c] = pliesToGo;
955 // Step 2. If either side cannot promote at least three plies before the other side then situation
956 // becomes too complex and we give up. Otherwise we determine the possibly "winning side"
957 if (abs(pliesToQueen[WHITE] - pliesToQueen[BLACK]) < 3)
960 winnerSide = (pliesToQueen[WHITE] < pliesToQueen[BLACK] ? WHITE : BLACK);
961 loserSide = opposite_color(winnerSide);
963 // Step 3. Can the losing side possibly create a new passed pawn and thus prevent the loss?
964 // We collect the potential candidates in potentialBB.
965 b1 = candidates = pos.pieces(PAWN, loserSide);
969 s1 = pop_1st_bit(&b1);
971 // Compute plies from queening
972 queeningSquare = relative_square(loserSide, make_square(square_file(s1), RANK_8));
973 movesToGo = rank_distance(s1, queeningSquare) - int(relative_rank(loserSide, s1) == RANK_2);
974 pliesToGo = 2 * movesToGo - int(loserSide == pos.side_to_move());
976 // Check if (without even considering any obstacles) we're too far away or doubled
977 if ( pliesToQueen[winnerSide] + 3 <= pliesToGo
978 || (squares_in_front_of(loserSide, s1) & pos.pieces(PAWN, loserSide)))
979 clear_bit(&candidates, s1);
982 // If any candidate is already a passed pawn it _may_ promote in time. We give up.
983 if (candidates & ei.pi->passed_pawns(loserSide))
986 // Step 4. Check new passed pawn creation through king capturing and sacrifices
991 s1 = pop_1st_bit(&b1);
993 // Compute plies from queening
994 queeningSquare = relative_square(loserSide, make_square(square_file(s1), RANK_8));
995 movesToGo = rank_distance(s1, queeningSquare) - int(relative_rank(loserSide, s1) == RANK_2);
996 pliesToGo = 2 * movesToGo - int(loserSide == pos.side_to_move());
998 // Generate list of obstacles
999 opposed = squares_in_front_of(loserSide, s1) & pos.pieces(PAWN, winnerSide);
1000 b2 = passed_pawn_mask(loserSide, s1) & pos.pieces(PAWN, winnerSide);
1004 // How many plies does it take to remove all the obstacles?
1006 int realObsCount = 0;
1007 int minKingDist = 256;
1012 s2 = pop_1st_bit(&b2);
1015 // Check pawns that can give support to overcome obstacle, for instance
1016 // black pawns: a4, b4 white: b2 then pawn in b4 is giving support.
1017 if (!opposed && square_file(s1) != square_file(s2))
1019 supBB = in_front_bb(winnerSide, s2 + pawn_push(winnerSide)) & neighboring_files_bb(s1) & candidates;
1021 while (supBB) // This while-loop could be replaced with supSq = LSB/MSB(supBB) (depending on color)
1023 supSq = pop_1st_bit(&supBB);
1024 movesToGo = Min(movesToGo, square_distance(s2, supSq) - 2);
1028 // Check pawns that can be sacrificed
1029 sacBB = passed_pawn_mask(winnerSide, s2) & neighboring_files_bb(s2) & candidates & ~(1ULL << s1);
1031 while (sacBB) // This while-loop could be replaced with sacSq = LSB/MSB(sacBB) (depending on color)
1033 sacSq = pop_1st_bit(&sacBB);
1034 movesToGo = Min(movesToGo, square_distance(s2, sacSq) - 2);
1037 // Good, obstacle can be destroyed with an immediate pawn sacrifice,
1038 // it's not a real obstacle and we have nothing to add to pliesToGo.
1042 // Plies needed to sacrifice the pawn
1043 sacptg += movesToGo * 2;
1046 // Plies needed for the king to capture opposing pawn
1047 minKingDist = Min(minKingDist, square_distance(pos.king_square(loserSide), s2));
1048 kingptg = (minKingDist + realObsCount) * 2;
1051 // Check if pawn sacrifice plan _may_ save the day
1052 if (pliesToQueen[winnerSide] + 3 > pliesToGo + sacptg)
1055 // Check if king capture plan _may_ save the day (contains some false positives)
1056 if (pliesToQueen[winnerSide] + 3 > pliesToGo + kingptg)
1060 // Winning pawn is unstoppable and will promote as first, return big score
1061 Score score = make_score(0, (Value) 0x500 - 0x20 * pliesToQueen[winnerSide]);
1062 return winnerSide == WHITE ? score : -score;
1066 // evaluate_space() computes the space evaluation for a given side. The
1067 // space evaluation is a simple bonus based on the number of safe squares
1068 // available for minor pieces on the central four files on ranks 2--4. Safe
1069 // squares one, two or three squares behind a friendly pawn are counted
1070 // twice. Finally, the space bonus is scaled by a weight taken from the
1071 // material hash table. The aim is to improve play on game opening.
1072 template<Color Us, bool HasPopCnt>
1073 int evaluate_space(const Position& pos, EvalInfo& ei) {
1075 const BitCountType Max15 = HasPopCnt ? CNT_POPCNT : CpuIs64Bit ? CNT64_MAX15 : CNT32_MAX15;
1076 const Color Them = (Us == WHITE ? BLACK : WHITE);
1078 // Find the safe squares for our pieces inside the area defined by
1079 // SpaceMask[]. A square is unsafe if it is attacked by an enemy
1080 // pawn, or if it is undefended and attacked by an enemy piece.
1081 Bitboard safe = SpaceMask[Us]
1082 & ~pos.pieces(PAWN, Us)
1083 & ~ei.attackedBy[Them][PAWN]
1084 & (ei.attackedBy[Us][0] | ~ei.attackedBy[Them][0]);
1086 // Find all squares which are at most three squares behind some friendly pawn
1087 Bitboard behind = pos.pieces(PAWN, Us);
1088 behind |= (Us == WHITE ? behind >> 8 : behind << 8);
1089 behind |= (Us == WHITE ? behind >> 16 : behind << 16);
1091 return count_1s<Max15>(safe) + count_1s<Max15>(behind & safe);
1095 // apply_weight() applies an evaluation weight to a value trying to prevent overflow
1097 inline Score apply_weight(Score v, Score w) {
1098 return make_score((int(mg_value(v)) * mg_value(w)) / 0x100,
1099 (int(eg_value(v)) * eg_value(w)) / 0x100);
1103 // scale_by_game_phase() interpolates between a middle game and an endgame score,
1104 // based on game phase. It also scales the return value by a ScaleFactor array.
1106 Value scale_by_game_phase(const Score& v, Phase ph, ScaleFactor sf) {
1108 assert(mg_value(v) > -VALUE_INFINITE && mg_value(v) < VALUE_INFINITE);
1109 assert(eg_value(v) > -VALUE_INFINITE && eg_value(v) < VALUE_INFINITE);
1110 assert(ph >= PHASE_ENDGAME && ph <= PHASE_MIDGAME);
1112 int ev = (eg_value(v) * int(sf)) / SCALE_FACTOR_NORMAL;
1113 int result = (mg_value(v) * int(ph) + ev * int(128 - ph)) / 128;
1114 return Value((result + GrainSize / 2) & ~(GrainSize - 1));
1118 // weight_option() computes the value of an evaluation weight, by combining
1119 // two UCI-configurable weights (midgame and endgame) with an internal weight.
1121 Score weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight) {
1123 // Scale option value from 100 to 256
1124 int mg = Options[mgOpt].value<int>() * 256 / 100;
1125 int eg = Options[egOpt].value<int>() * 256 / 100;
1127 return apply_weight(make_score(mg, eg), internalWeight);
1131 // init_safety() initizes the king safety evaluation, based on UCI
1132 // parameters. It is called from read_weights().
1134 void init_safety() {
1136 const Value MaxSlope = Value(30);
1137 const Value Peak = Value(1280);
1140 // First setup the base table
1141 for (int i = 0; i < 100; i++)
1143 t[i] = Value(int(0.4 * i * i));
1146 t[i] = Min(t[i], t[i - 1] + MaxSlope);
1148 t[i] = Min(t[i], Peak);
1151 // Then apply the weights and get the final KingDangerTable[] array
1152 for (Color c = WHITE; c <= BLACK; c++)
1153 for (int i = 0; i < 100; i++)
1154 KingDangerTable[c][i] = apply_weight(make_score(t[i], 0), Weights[KingDangerUs + c]);
1158 // trace_row() is an helper function used by tracing code to register the
1159 // values of a single evaluation term.
1161 void trace_row(const char *name, int idx) {
1163 Score term_w = TracedTerms[WHITE][idx];
1164 Score term_b = TracedTerms[BLACK][idx];
1167 case PST: case IMBALANCE: case PAWN: case UNSTOPPABLE: case TOTAL:
1168 TraceStream << std::setw(20) << name << " | --- --- | --- --- | "
1169 << std::setw(6) << to_cp(mg_value(term_w)) << " "
1170 << std::setw(6) << to_cp(eg_value(term_w)) << " \n";
1173 TraceStream << std::setw(20) << name << " | " << std::noshowpos
1174 << std::setw(5) << to_cp(mg_value(term_w)) << " "
1175 << std::setw(5) << to_cp(eg_value(term_w)) << " | "
1176 << std::setw(5) << to_cp(mg_value(term_b)) << " "
1177 << std::setw(5) << to_cp(eg_value(term_b)) << " | "
1179 << std::setw(6) << to_cp(mg_value(term_w - term_b)) << " "
1180 << std::setw(6) << to_cp(eg_value(term_w - term_b)) << " \n";
1186 /// trace_evaluate() is like evaluate() but instead of a value returns a string
1187 /// suitable to be print on stdout with the detailed descriptions and values of
1188 /// each evaluation term. Used mainly for debugging.
1190 std::string trace_evaluate(const Position& pos) {
1195 TraceStream.str("");
1196 TraceStream << std::showpoint << std::showpos << std::fixed << std::setprecision(2);
1197 memset(TracedTerms, 0, 2 * 16 * sizeof(Score));
1199 do_evaluate<false, true>(pos, margin);
1201 totals = TraceStream.str();
1202 TraceStream.str("");
1204 TraceStream << std::setw(21) << "Eval term " << "| White | Black | Total \n"
1205 << " | MG EG | MG EG | MG EG \n"
1206 << "---------------------+-------------+-------------+---------------\n";
1208 trace_row("Material, PST, Tempo", PST);
1209 trace_row("Material imbalance", IMBALANCE);
1210 trace_row("Pawns", PAWN);
1211 trace_row("Knights", KNIGHT);
1212 trace_row("Bishops", BISHOP);
1213 trace_row("Rooks", ROOK);
1214 trace_row("Queens", QUEEN);
1215 trace_row("Mobility", MOBILITY);
1216 trace_row("King safety", KING);
1217 trace_row("Threats", THREAT);
1218 trace_row("Passed pawns", PASSED);
1219 trace_row("Unstoppable pawns", UNSTOPPABLE);
1220 trace_row("Space", SPACE);
1222 TraceStream << "---------------------+-------------+-------------+---------------\n";
1223 trace_row("Total", TOTAL);
1224 TraceStream << totals;
1226 return TraceStream.str();