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 Marco Costalba
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/>.
33 #include "ucioption.h"
37 //// Local definitions
42 const int Sign[2] = {1, -1};
44 // Evaluation grain size, must be a power of 2.
45 const int GrainSize = 4;
48 int WeightMobilityMidgame = 0x100;
49 int WeightMobilityEndgame = 0x100;
50 int WeightPawnStructureMidgame = 0x100;
51 int WeightPawnStructureEndgame = 0x100;
52 int WeightPassedPawnsMidgame = 0x100;
53 int WeightPassedPawnsEndgame = 0x100;
54 int WeightKingSafety[2] = { 0x100, 0x100 };
57 // Internal evaluation weights. These are applied on top of the evaluation
58 // weights read from UCI parameters. The purpose is to be able to change
59 // the evaluation weights while keeping the default values of the UCI
60 // parameters at 100, which looks prettier.
61 const int WeightMobilityMidgameInternal = 0x100;
62 const int WeightMobilityEndgameInternal = 0x100;
63 const int WeightPawnStructureMidgameInternal = 0x100;
64 const int WeightPawnStructureEndgameInternal = 0x100;
65 const int WeightPassedPawnsMidgameInternal = 0x100;
66 const int WeightPassedPawnsEndgameInternal = 0x100;
67 const int WeightKingSafetyInternal = 0x110;
68 const int WeightKingOppSafetyInternal = 0x110;
69 const int WeightSpaceInternal = 0x30;
71 // Visually better to define tables constants
74 // Knight mobility bonus in middle game and endgame, indexed by the number
75 // of attacked squares not occupied by friendly piecess.
76 const Value MidgameKnightMobilityBonus[] = {
78 V(-30), V(-20),V(-10), V(0), V(10), V(20), V(25), V(30), V(30)
81 const Value EndgameKnightMobilityBonus[] = {
83 V(-30), V(-20),V(-10), V(0), V(10), V(20), V(25), V(30), V(30)
86 // Bishop mobility bonus in middle game and endgame, indexed by the number
87 // of attacked squares not occupied by friendly pieces. X-ray attacks through
88 // queens are also included.
89 const Value MidgameBishopMobilityBonus[] = {
91 V(-30), V(-15), V(0), V(15), V(30), V(45), V(58), V(66),
92 // 8 9 10 11 12 13 14 15
93 V( 72), V( 76), V(78), V(80), V(81), V(82), V(83), V(83)
96 const Value EndgameBishopMobilityBonus[] = {
98 V(-30), V(-15), V(0), V(15), V(30), V(45), V(58), V(66),
99 // 8 9 10 11 12 13 14 15
100 V( 72), V( 76), V(78), V(80), V(81), V(82), V(83), V(83)
103 // Rook mobility bonus in middle game and endgame, indexed by the number
104 // of attacked squares not occupied by friendly pieces. X-ray attacks through
105 // queens and rooks are also included.
106 const Value MidgameRookMobilityBonus[] = {
108 V(-18), V(-12), V(-6), V(0), V(6), V(12), V(16), V(21),
109 // 8 9 10 11 12 13 14 15
110 V( 24), V( 27), V(28), V(29), V(30), V(31), V(32), V(33)
113 const Value EndgameRookMobilityBonus[] = {
115 V(-30), V(-18), V(-6), V(6), V(18), V(30), V(42), V(54),
116 // 8 9 10 11 12 13 14 15
117 V( 66), V( 74), V(78), V(80), V(81), V(82), V(83), V(83)
120 // Queen mobility bonus in middle game and endgame, indexed by the number
121 // of attacked squares not occupied by friendly pieces.
122 const Value MidgameQueenMobilityBonus[] = {
124 V(-10), V(-8), V(-6), V(-4), V(-2), V( 0), V( 2), V( 4),
125 // 8 9 10 11 12 13 14 15
126 V( 6), V( 8), V(10), V(12), V(13), V(14), V(15), V(16),
127 // 16 17 18 19 20 21 22 23
128 V( 16), V(16), V(16), V(16), V(16), V(16), V(16), V(16),
129 // 24 25 26 27 28 29 30 31
130 V( 16), V(16), V(16), V(16), V(16), V(16), V(16), V(16)
133 const Value EndgameQueenMobilityBonus[] = {
135 V(-20),V(-15),V(-10), V(-5), V( 0), V( 5), V(10), V(15),
136 // 8 9 10 11 12 13 14 15
137 V( 19), V(23), V(27), V(29), V(30), V(30), V(30), V(30),
138 // 16 17 18 19 20 21 22 23
139 V( 30), V(30), V(30), V(30), V(30), V(30), V(30), V(30),
140 // 24 25 26 27 28 29 30 31
141 V( 30), V(30), V(30), V(30), V(30), V(30), V(30), V(30)
144 // Outpost bonuses for knights and bishops, indexed by square (from white's
146 const Value KnightOutpostBonus[64] = {
148 V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // 1
149 V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // 2
150 V(0), V(0), V(5),V(10),V(10), V(5), V(0), V(0), // 3
151 V(0), V(5),V(20),V(30),V(30),V(20), V(5), V(0), // 4
152 V(0),V(10),V(30),V(40),V(40),V(30),V(10), V(0), // 5
153 V(0), V(5),V(20),V(20),V(20),V(20), V(5), V(0), // 6
154 V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // 7
155 V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0) // 8
158 const Value BishopOutpostBonus[64] = {
160 V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // 1
161 V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // 2
162 V(0), V(0), V(5), V(5), V(5), V(5), V(0), V(0), // 3
163 V(0), V(5),V(10),V(10),V(10),V(10), V(5), V(0), // 4
164 V(0),V(10),V(20),V(20),V(20),V(20),V(10), V(0), // 5
165 V(0), V(5), V(8), V(8), V(8), V(8), V(5), V(0), // 6
166 V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // 7
167 V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0) // 8
170 // Bonus for unstoppable passed pawns:
171 const Value UnstoppablePawnValue = Value(0x500);
173 // Rooks and queens on the 7th rank:
174 const Value MidgameRookOn7thBonus = Value(50);
175 const Value EndgameRookOn7thBonus = Value(100);
176 const Value MidgameQueenOn7thBonus = Value(25);
177 const Value EndgameQueenOn7thBonus = Value(50);
179 // Rooks on open files:
180 const Value RookOpenFileBonus = Value(40);
181 const Value RookHalfOpenFileBonus = Value(20);
183 // Penalty for rooks trapped inside a friendly king which has lost the
185 const Value TrappedRookPenalty = Value(180);
187 // Penalty for a bishop on a7/h7 (a2/h2 for black) which is trapped by
189 const Value TrappedBishopA7H7Penalty = Value(300);
191 // Bitboard masks for detecting trapped bishops on a7/h7 (a2/h2 for black):
192 const Bitboard MaskA7H7[2] = {
193 ((1ULL << SQ_A7) | (1ULL << SQ_H7)),
194 ((1ULL << SQ_A2) | (1ULL << SQ_H2))
197 // Penalty for a bishop on a1/h1 (a8/h8 for black) which is trapped by
198 // a friendly pawn on b2/g2 (b7/g7 for black). This can obviously only
199 // happen in Chess960 games.
200 const Value TrappedBishopA1H1Penalty = Value(100);
202 // Bitboard masks for detecting trapped bishops on a1/h1 (a8/h8 for black):
203 const Bitboard MaskA1H1[2] = {
204 ((1ULL << SQ_A1) | (1ULL << SQ_H1)),
205 ((1ULL << SQ_A8) | (1ULL << SQ_H8))
208 // The SpaceMask[color] contains area of the board which is consdered by
209 // the space evaluation. In the middle game, each side is given a bonus
210 // based on how many squares inside this area are safe and available for
211 // friendly minor pieces.
212 const Bitboard SpaceMask[2] = {
213 (1ULL<<SQ_C2) | (1ULL<<SQ_D2) | (1ULL<<SQ_E2) | (1ULL<<SQ_F2) |
214 (1ULL<<SQ_C3) | (1ULL<<SQ_D3) | (1ULL<<SQ_E3) | (1ULL<<SQ_F3) |
215 (1ULL<<SQ_C4) | (1ULL<<SQ_D4) | (1ULL<<SQ_E4) | (1ULL<<SQ_F4),
216 (1ULL<<SQ_C7) | (1ULL<<SQ_D7) | (1ULL<<SQ_E7) | (1ULL<<SQ_F7) |
217 (1ULL<<SQ_C6) | (1ULL<<SQ_D6) | (1ULL<<SQ_E6) | (1ULL<<SQ_F6) |
218 (1ULL<<SQ_C5) | (1ULL<<SQ_D5) | (1ULL<<SQ_E5) | (1ULL<<SQ_F5)
221 /// King safety constants and variables. The king safety scores are taken
222 /// from the array SafetyTable[]. Various little "meta-bonuses" measuring
223 /// the strength of the attack are added up into an integer, which is used
224 /// as an index to SafetyTable[].
226 // Attack weights for each piece type.
227 const int QueenAttackWeight = 5;
228 const int RookAttackWeight = 3;
229 const int BishopAttackWeight = 2;
230 const int KnightAttackWeight = 2;
232 // Bonuses for safe checks for each piece type.
233 int QueenContactCheckBonus = 3;
234 int QueenCheckBonus = 2;
235 int RookCheckBonus = 1;
236 int BishopCheckBonus = 1;
237 int KnightCheckBonus = 1;
238 int DiscoveredCheckBonus = 3;
240 // Scan for queen contact mates?
241 const bool QueenContactMates = true;
243 // Bonus for having a mate threat.
244 int MateThreatBonus = 3;
246 // InitKingDanger[] contains bonuses based on the position of the defending
248 const int InitKingDanger[64] = {
249 2, 0, 2, 5, 5, 2, 0, 2,
250 2, 2, 4, 8, 8, 4, 2, 2,
251 7, 10, 12, 12, 12, 12, 10, 7,
252 15, 15, 15, 15, 15, 15, 15, 15,
253 15, 15, 15, 15, 15, 15, 15, 15,
254 15, 15, 15, 15, 15, 15, 15, 15,
255 15, 15, 15, 15, 15, 15, 15, 15,
256 15, 15, 15, 15, 15, 15, 15, 15
259 // SafetyTable[] contains the actual king safety scores. It is initialized
261 Value SafetyTable[100];
263 // Pawn and material hash tables, indexed by the current thread id
264 PawnInfoTable *PawnTable[8] = {0, 0, 0, 0, 0, 0, 0, 0};
265 MaterialInfoTable *MaterialTable[8] = {0, 0, 0, 0, 0, 0, 0, 0};
267 // Sizes of pawn and material hash tables
268 const int PawnTableSize = 16384;
269 const int MaterialTableSize = 1024;
271 // Array which gives the number of nonzero bits in an 8-bit integer:
272 uint8_t BitCount8Bit[256];
274 // Function prototypes
275 void evaluate_knight(const Position &p, Square s, Color us, EvalInfo &ei);
276 void evaluate_bishop(const Position &p, Square s, Color us, EvalInfo &ei);
277 void evaluate_rook(const Position &p, Square s, Color us, EvalInfo &ei);
278 void evaluate_queen(const Position &p, Square s, Color us, EvalInfo &ei);
279 void evaluate_king(const Position &p, Square s, Color us, EvalInfo &ei);
281 void evaluate_passed_pawns(const Position &pos, EvalInfo &ei);
282 void evaluate_trapped_bishop_a7h7(const Position &pos, Square s, Color us,
284 void evaluate_trapped_bishop_a1h1(const Position &pos, Square s, Color us,
287 void evaluate_space(const Position &p, Color us, EvalInfo &ei);
288 inline Value apply_weight(Value v, int w);
289 Value scale_by_game_phase(Value mv, Value ev, Phase ph, const ScaleFactor sf[]);
291 int count_1s_8bit(Bitboard b);
293 int compute_weight(int uciWeight, int internalWeight);
294 int weight_option(const std::string& opt, int weight);
304 /// evaluate() is the main evaluation function. It always computes two
305 /// values, an endgame score and a middle game score, and interpolates
306 /// between them based on the remaining material.
308 Value evaluate(const Position &pos, EvalInfo &ei, int threadID) {
311 assert(threadID >= 0 && threadID < THREAD_MAX);
313 memset(&ei, 0, sizeof(EvalInfo));
315 // Initialize by reading the incrementally updated scores included in the
316 // position object (material + piece square tables)
317 ei.mgValue = pos.mg_value();
318 ei.egValue = pos.eg_value();
320 // Probe the material hash table
321 ei.mi = MaterialTable[threadID]->get_material_info(pos);
322 ei.mgValue += ei.mi->mg_value();
323 ei.egValue += ei.mi->eg_value();
325 // If we have a specialized evaluation function for the current material
326 // configuration, call it and return
327 if (ei.mi->specialized_eval_exists())
328 return ei.mi->evaluate(pos);
330 // After get_material_info() call that modifies them
331 ScaleFactor factor[2];
332 factor[WHITE] = ei.mi->scale_factor(pos, WHITE);
333 factor[BLACK] = ei.mi->scale_factor(pos, BLACK);
335 // Probe the pawn hash table
336 ei.pi = PawnTable[threadID]->get_pawn_info(pos);
337 ei.mgValue += apply_weight(ei.pi->mg_value(), WeightPawnStructureMidgame);
338 ei.egValue += apply_weight(ei.pi->eg_value(), WeightPawnStructureEndgame);
340 // Initialize king attack bitboards and king attack zones for both sides
341 ei.attackedBy[WHITE][KING] = pos.piece_attacks<KING>(pos.king_square(WHITE));
342 ei.attackedBy[BLACK][KING] = pos.piece_attacks<KING>(pos.king_square(BLACK));
343 ei.kingZone[WHITE] = ei.attackedBy[BLACK][KING] | (ei.attackedBy[BLACK][KING] >> 8);
344 ei.kingZone[BLACK] = ei.attackedBy[WHITE][KING] | (ei.attackedBy[WHITE][KING] << 8);
346 // Initialize pawn attack bitboards for both sides
347 ei.attackedBy[WHITE][PAWN] = ((pos.pawns(WHITE) << 9) & ~FileABB) | ((pos.pawns(WHITE) << 7) & ~FileHBB);
348 ei.attackedBy[BLACK][PAWN] = ((pos.pawns(BLACK) >> 7) & ~FileABB) | ((pos.pawns(BLACK) >> 9) & ~FileHBB);
349 ei.kingAttackersCount[WHITE] = count_1s_max_15(ei.attackedBy[WHITE][PAWN] & ei.attackedBy[BLACK][KING])/2;
350 ei.kingAttackersCount[BLACK] = count_1s_max_15(ei.attackedBy[BLACK][PAWN] & ei.attackedBy[WHITE][KING])/2;
353 for (Color c = WHITE; c <= BLACK; c++)
356 for (int i = 0; i < pos.piece_count(c, KNIGHT); i++)
357 evaluate_knight(pos, pos.piece_list(c, KNIGHT, i), c, ei);
360 for (int i = 0; i < pos.piece_count(c, BISHOP); i++)
361 evaluate_bishop(pos, pos.piece_list(c, BISHOP, i), c, ei);
364 for (int i = 0; i < pos.piece_count(c, ROOK); i++)
365 evaluate_rook(pos, pos.piece_list(c, ROOK, i), c, ei);
368 for(int i = 0; i < pos.piece_count(c, QUEEN); i++)
369 evaluate_queen(pos, pos.piece_list(c, QUEEN, i), c, ei);
371 // Special pattern: trapped bishops on a7/h7/a2/h2
372 Bitboard b = pos.bishops(c) & MaskA7H7[c];
375 Square s = pop_1st_bit(&b);
376 evaluate_trapped_bishop_a7h7(pos, s, c, ei);
379 // Special pattern: trapped bishops on a1/h1/a8/h8 in Chess960:
382 b = pos.bishops(c) & MaskA1H1[c];
385 Square s = pop_1st_bit(&b);
386 evaluate_trapped_bishop_a1h1(pos, s, c, ei);
390 // Sum up all attacked squares
391 ei.attackedBy[c][0] = ei.attackedBy[c][PAWN] | ei.attackedBy[c][KNIGHT]
392 | ei.attackedBy[c][BISHOP] | ei.attackedBy[c][ROOK]
393 | ei.attackedBy[c][QUEEN] | ei.attackedBy[c][KING];
396 // Kings. Kings are evaluated after all other pieces for both sides,
397 // because we need complete attack information for all pieces when computing
398 // the king safety evaluation.
399 for (Color c = WHITE; c <= BLACK; c++)
400 evaluate_king(pos, pos.king_square(c), c, ei);
402 // Evaluate passed pawns. We evaluate passed pawns for both sides at once,
403 // because we need to know which side promotes first in positions where
404 // both sides have an unstoppable passed pawn.
405 if (ei.pi->passed_pawns())
406 evaluate_passed_pawns(pos, ei);
408 Phase phase = pos.game_phase();
410 // Middle-game specific evaluation terms
411 if (phase > PHASE_ENDGAME)
413 // Pawn storms in positions with opposite castling.
414 if ( square_file(pos.king_square(WHITE)) >= FILE_E
415 && square_file(pos.king_square(BLACK)) <= FILE_D)
417 ei.mgValue += ei.pi->queenside_storm_value(WHITE)
418 - ei.pi->kingside_storm_value(BLACK);
420 else if ( square_file(pos.king_square(WHITE)) <= FILE_D
421 && square_file(pos.king_square(BLACK)) >= FILE_E)
423 ei.mgValue += ei.pi->kingside_storm_value(WHITE)
424 - ei.pi->queenside_storm_value(BLACK);
426 // Evaluate space for both sides
427 if (ei.mi->space_weight() > 0)
429 evaluate_space(pos, WHITE, ei);
430 evaluate_space(pos, BLACK, ei);
435 ei.mgValue += apply_weight(ei.mgMobility, WeightMobilityMidgame);
436 ei.egValue += apply_weight(ei.egMobility, WeightMobilityEndgame);
438 // If we don't already have an unusual scale factor, check for opposite
439 // colored bishop endgames, and use a lower scale for those
440 if ( phase < PHASE_MIDGAME
441 && pos.opposite_colored_bishops()
442 && ( (factor[WHITE] == SCALE_FACTOR_NORMAL && ei.egValue > Value(0))
443 || (factor[BLACK] == SCALE_FACTOR_NORMAL && ei.egValue < Value(0))))
447 // Only the two bishops ?
448 if ( pos.non_pawn_material(WHITE) == BishopValueMidgame
449 && pos.non_pawn_material(BLACK) == BishopValueMidgame)
451 // Check for KBP vs KB with only a single pawn that is almost
452 // certainly a draw or at least two pawns.
453 bool one_pawn = (pos.piece_count(WHITE, PAWN) + pos.piece_count(BLACK, PAWN) == 1);
454 sf = one_pawn ? ScaleFactor(8) : ScaleFactor(32);
457 // Endgame with opposite-colored bishops, but also other pieces. Still
458 // a bit drawish, but not as drawish as with only the two bishops.
459 sf = ScaleFactor(50);
461 if (factor[WHITE] == SCALE_FACTOR_NORMAL)
463 if (factor[BLACK] == SCALE_FACTOR_NORMAL)
467 // Interpolate between the middle game and the endgame score, and
469 Color stm = pos.side_to_move();
471 Value v = Sign[stm] * scale_by_game_phase(ei.mgValue, ei.egValue, phase, factor);
473 return (ei.mateThreat[stm] == MOVE_NONE ? v : 8 * QueenValueMidgame - v);
477 /// quick_evaluate() does a very approximate evaluation of the current position.
478 /// It currently considers only material and piece square table scores. Perhaps
479 /// we should add scores from the pawn and material hash tables?
481 Value quick_evaluate(const Position &pos) {
486 ScaleFactor sf[2] = {SCALE_FACTOR_NORMAL, SCALE_FACTOR_NORMAL};
488 Value mgv = pos.mg_value();
489 Value egv = pos.eg_value();
490 Phase ph = pos.game_phase();
491 Color stm = pos.side_to_move();
493 return Sign[stm] * scale_by_game_phase(mgv, egv, ph, sf);
497 /// init_eval() initializes various tables used by the evaluation function.
499 void init_eval(int threads) {
501 assert(threads <= THREAD_MAX);
503 for (int i = 0; i < THREAD_MAX; i++)
508 delete MaterialTable[i];
510 MaterialTable[i] = NULL;
514 PawnTable[i] = new PawnInfoTable(PawnTableSize);
515 if (!MaterialTable[i])
516 MaterialTable[i] = new MaterialInfoTable(MaterialTableSize);
519 for (Bitboard b = 0ULL; b < 256ULL; b++)
520 BitCount8Bit[b] = count_1s(b);
524 /// quit_eval() releases heap-allocated memory at program termination.
528 for (int i = 0; i < THREAD_MAX; i++)
531 delete MaterialTable[i];
536 /// read_weights() reads evaluation weights from the corresponding UCI
539 void read_weights(Color us) {
541 WeightMobilityMidgame = weight_option("Mobility (Middle Game)", WeightMobilityMidgameInternal);
542 WeightMobilityEndgame = weight_option("Mobility (Endgame)", WeightMobilityEndgameInternal);
543 WeightPawnStructureMidgame = weight_option("Pawn Structure (Middle Game)", WeightPawnStructureMidgameInternal);
544 WeightPawnStructureEndgame = weight_option("Pawn Structure (Endgame)", WeightPawnStructureEndgameInternal);
545 WeightPassedPawnsMidgame = weight_option("Passed Pawns (Middle Game)", WeightPassedPawnsMidgameInternal);
546 WeightPassedPawnsEndgame = weight_option("Passed Pawns (Endgame)", WeightPassedPawnsEndgameInternal);
548 Color them = opposite_color(us);
550 WeightKingSafety[us] = weight_option("Cowardice", WeightKingSafetyInternal);
551 WeightKingSafety[them] = weight_option("Aggressiveness", WeightKingOppSafetyInternal);
552 WeightSpace = weight_option("Space", WeightSpaceInternal);
560 // evaluate_common() computes terms common to all pieces attack
562 template<PieceType Piece>
563 int evaluate_common(const Position& p, const Bitboard& b, Color us, EvalInfo& ei, Square s = SQ_NONE) {
565 static const int AttackWeight[] = { 0, 0, KnightAttackWeight, BishopAttackWeight, RookAttackWeight, QueenAttackWeight };
566 static const Value* MgBonus[] = { 0, 0, MidgameKnightMobilityBonus, MidgameBishopMobilityBonus, MidgameRookMobilityBonus, MidgameQueenMobilityBonus };
567 static const Value* EgBonus[] = { 0, 0, EndgameKnightMobilityBonus, EndgameBishopMobilityBonus, EndgameRookMobilityBonus, EndgameQueenMobilityBonus };
568 static const Value* OutpostBonus[] = { 0, 0, KnightOutpostBonus, BishopOutpostBonus, 0, 0 };
570 Color them = opposite_color(us);
572 // Update attack info
573 ei.attackedBy[us][Piece] |= b;
576 if (b & ei.kingZone[us])
578 ei.kingAttackersCount[us]++;
579 ei.kingAttackersWeight[us] += AttackWeight[Piece];
580 Bitboard bb = (b & ei.attackedBy[them][KING]);
582 ei.kingAdjacentZoneAttacksCount[us] += count_1s_max_15(bb);
585 // Remove squares protected by enemy pawns
586 Bitboard bb = (b & ~ei.attackedBy[them][PAWN]);
589 int mob = count_1s_max_15(bb & ~p.pieces_of_color(us));
590 ei.mgMobility += Sign[us] * MgBonus[Piece][mob];
591 ei.egMobility += Sign[us] * EgBonus[Piece][mob];
593 // Bishop and Knight outposts
594 if ( (Piece != BISHOP && Piece != KNIGHT) // compile time condition
595 || !p.square_is_weak(s, them))
598 // Initial bonus based on square
600 v = bonus = OutpostBonus[Piece][relative_square(us, s)];
602 // Increase bonus if supported by pawn, especially if the opponent has
603 // no minor piece which can exchange the outpost piece
604 if (v && (p.pawn_attacks(them, s) & p.pawns(us)))
607 if ( p.piece_count(them, KNIGHT) == 0
608 && (SquaresByColorBB[square_color(s)] & p.bishops(them)) == EmptyBoardBB)
611 ei.mgValue += Sign[us] * bonus;
612 ei.egValue += Sign[us] * bonus;
617 // evaluate_knight() assigns bonuses and penalties to a knight of a given
618 // color on a given square.
620 void evaluate_knight(const Position& p, Square s, Color us, EvalInfo& ei) {
622 // Attacks, mobility and outposts
623 evaluate_common<KNIGHT>(p, p.piece_attacks<KNIGHT>(s), us, ei, s);
627 // evaluate_bishop() assigns bonuses and penalties to a bishop of a given
628 // color on a given square.
630 void evaluate_bishop(const Position& p, Square s, Color us, EvalInfo& ei) {
632 Bitboard b = bishop_attacks_bb(s, p.occupied_squares() & ~p.queens(us));
634 // Attacks, mobility and outposts
635 evaluate_common<BISHOP>(p, b, us, ei, s);
639 // evaluate_rook() assigns bonuses and penalties to a rook of a given
640 // color on a given square.
642 void evaluate_rook(const Position& p, Square s, Color us, EvalInfo& ei) {
644 Bitboard b = rook_attacks_bb(s, p.occupied_squares() & ~p.rooks_and_queens(us));
646 // Attacks and mobility
647 int mob = evaluate_common<ROOK>(p, b, us, ei);
650 Color them = opposite_color(us);
652 if ( relative_rank(us, s) == RANK_7
653 && relative_rank(us, p.king_square(them)) == RANK_8)
655 ei.mgValue += Sign[us] * MidgameRookOn7thBonus;
656 ei.egValue += Sign[us] * EndgameRookOn7thBonus;
659 // Open and half-open files
660 File f = square_file(s);
661 if (ei.pi->file_is_half_open(us, f))
663 if (ei.pi->file_is_half_open(them, f))
665 ei.mgValue += Sign[us] * RookOpenFileBonus;
666 ei.egValue += Sign[us] * RookOpenFileBonus;
670 ei.mgValue += Sign[us] * RookHalfOpenFileBonus;
671 ei.egValue += Sign[us] * RookHalfOpenFileBonus;
675 // Penalize rooks which are trapped inside a king. Penalize more if
676 // king has lost right to castle
677 if (mob > 6 || ei.pi->file_is_half_open(us, f))
680 Square ksq = p.king_square(us);
682 if ( square_file(ksq) >= FILE_E
683 && square_file(s) > square_file(ksq)
684 && (relative_rank(us, ksq) == RANK_1 || square_rank(ksq) == square_rank(s)))
686 // Is there a half-open file between the king and the edge of the board?
687 if (!ei.pi->has_open_file_to_right(us, square_file(ksq)))
688 ei.mgValue -= p.can_castle(us)? Sign[us] * ((TrappedRookPenalty - mob * 16) / 2)
689 : Sign[us] * (TrappedRookPenalty - mob * 16);
691 else if ( square_file(ksq) <= FILE_D
692 && square_file(s) < square_file(ksq)
693 && (relative_rank(us, ksq) == RANK_1 || square_rank(ksq) == square_rank(s)))
695 // Is there a half-open file between the king and the edge of the board?
696 if (!ei.pi->has_open_file_to_left(us, square_file(ksq)))
697 ei.mgValue -= p.can_castle(us)? Sign[us] * ((TrappedRookPenalty - mob * 16) / 2)
698 : Sign[us] * (TrappedRookPenalty - mob * 16);
703 // evaluate_queen() assigns bonuses and penalties to a queen of a given
704 // color on a given square.
706 void evaluate_queen(const Position& p, Square s, Color us, EvalInfo& ei) {
708 // Attacks and mobility
709 evaluate_common<QUEEN>(p, p.piece_attacks<QUEEN>(s), us, ei);
712 Color them = opposite_color(us);
714 if ( relative_rank(us, s) == RANK_7
715 && relative_rank(us, p.king_square(them)) == RANK_8)
717 ei.mgValue += Sign[us] * MidgameQueenOn7thBonus;
718 ei.egValue += Sign[us] * EndgameQueenOn7thBonus;
722 inline Bitboard shiftRowsDown(const Bitboard& b, int num) {
724 return b >> (num << 3);
727 // evaluate_king() assigns bonuses and penalties to a king of a given
728 // color on a given square.
730 void evaluate_king(const Position& p, Square s, Color us, EvalInfo& ei) {
732 int shelter = 0, sign = Sign[us];
735 if (relative_rank(us, s) <= RANK_4)
737 Bitboard pawns = p.pawns(us) & this_and_neighboring_files_bb(s);
738 Rank r = square_rank(s);
739 for (int i = 1; i < 4; i++)
740 shelter += count_1s_8bit(shiftRowsDown(pawns, r+i*sign)) * (128>>i);
742 ei.mgValue += sign * Value(shelter);
745 // King safety. This is quite complicated, and is almost certainly far
746 // from optimally tuned.
747 Color them = opposite_color(us);
749 if ( p.piece_count(them, QUEEN) >= 1
750 && ei.kingAttackersCount[them] >= 2
751 && p.non_pawn_material(them) >= QueenValueMidgame + RookValueMidgame
752 && ei.kingAdjacentZoneAttacksCount[them])
754 // Is it the attackers turn to move?
755 bool sente = (them == p.side_to_move());
757 // Find the attacked squares around the king which has no defenders
758 // apart from the king itself
759 Bitboard undefended =
760 ei.attacked_by(them) & ~ei.attacked_by(us, PAWN)
761 & ~ei.attacked_by(us, KNIGHT) & ~ei.attacked_by(us, BISHOP)
762 & ~ei.attacked_by(us, ROOK) & ~ei.attacked_by(us, QUEEN)
763 & ei.attacked_by(us, KING);
765 Bitboard occ = p.occupied_squares(), b, b2;
767 // Initialize the 'attackUnits' variable, which is used later on as an
768 // index to the SafetyTable[] array. The initial value is based on the
769 // number and types of the attacking pieces, the number of attacked and
770 // undefended squares around the king, the square of the king, and the
771 // quality of the pawn shelter.
773 Min((ei.kingAttackersCount[them] * ei.kingAttackersWeight[them]) / 2, 25)
774 + (ei.kingAdjacentZoneAttacksCount[them] + count_1s_max_15(undefended)) * 3
775 + InitKingDanger[relative_square(us, s)] - (shelter >> 5);
777 // Analyse safe queen contact checks
778 b = undefended & ei.attacked_by(them, QUEEN) & ~p.pieces_of_color(them);
781 Bitboard attackedByOthers =
782 ei.attacked_by(them, PAWN) | ei.attacked_by(them, KNIGHT)
783 | ei.attacked_by(them, BISHOP) | ei.attacked_by(them, ROOK);
785 b &= attackedByOthers;
788 // The bitboard b now contains the squares available for safe queen
790 int count = count_1s_max_15(b);
791 attackUnits += QueenContactCheckBonus * count * (sente ? 2 : 1);
793 // Is there a mate threat?
794 if (QueenContactMates && !p.is_check())
796 Bitboard escapeSquares =
797 p.piece_attacks<KING>(s) & ~p.pieces_of_color(us) & ~attackedByOthers;
801 Square from, to = pop_1st_bit(&b);
802 if (!(escapeSquares & ~queen_attacks_bb(to, occ & ClearMaskBB[s])))
804 // We have a mate, unless the queen is pinned or there
805 // is an X-ray attack through the queen.
806 for (int i = 0; i < p.piece_count(them, QUEEN); i++)
808 from = p.piece_list(them, QUEEN, i);
809 if ( bit_is_set(p.piece_attacks<QUEEN>(from), to)
810 && !bit_is_set(p.pinned_pieces(them), from)
811 && !(rook_attacks_bb(to, occ & ClearMaskBB[from]) & p.rooks_and_queens(us))
812 && !(rook_attacks_bb(to, occ & ClearMaskBB[from]) & p.rooks_and_queens(us)))
814 ei.mateThreat[them] = make_move(from, to);
822 // Analyse safe distance checks
823 if (QueenCheckBonus > 0 || RookCheckBonus > 0)
825 b = p.piece_attacks<ROOK>(s) & ~p.pieces_of_color(them) & ~ei.attacked_by(us);
828 b2 = b & ei.attacked_by(them, QUEEN);
830 attackUnits += QueenCheckBonus * count_1s_max_15(b2);
833 b2 = b & ei.attacked_by(them, ROOK);
835 attackUnits += RookCheckBonus * count_1s_max_15(b2);
837 if (QueenCheckBonus > 0 || BishopCheckBonus > 0)
839 b = p.piece_attacks<BISHOP>(s) & ~p.pieces_of_color(them) & ~ei.attacked_by(us);
842 b2 = b & ei.attacked_by(them, QUEEN);
844 attackUnits += QueenCheckBonus * count_1s_max_15(b2);
847 b2 = b & ei.attacked_by(them, BISHOP);
849 attackUnits += BishopCheckBonus * count_1s_max_15(b2);
851 if (KnightCheckBonus > 0)
853 b = p.piece_attacks<KNIGHT>(s) & ~p.pieces_of_color(them) & ~ei.attacked_by(us);
856 b2 = b & ei.attacked_by(them, KNIGHT);
858 attackUnits += KnightCheckBonus * count_1s_max_15(b2);
861 // Analyse discovered checks (only for non-pawns right now, consider
862 // adding pawns later).
863 if (DiscoveredCheckBonus)
865 b = p.discovered_check_candidates(them) & ~p.pawns();
867 attackUnits += DiscoveredCheckBonus * count_1s_max_15(b) * (sente? 2 : 1);
870 // Has a mate threat been found? We don't do anything here if the
871 // side with the mating move is the side to move, because in that
872 // case the mating side will get a huge bonus at the end of the main
873 // evaluation function instead.
874 if (ei.mateThreat[them] != MOVE_NONE)
875 attackUnits += MateThreatBonus;
877 // Ensure that attackUnits is between 0 and 99, in order to avoid array
878 // out of bounds errors:
882 if (attackUnits >= 100)
885 // Finally, extract the king safety score from the SafetyTable[] array.
886 // Add the score to the evaluation, and also to ei.futilityMargin. The
887 // reason for adding the king safety score to the futility margin is
888 // that the king safety scores can sometimes be very big, and that
889 // capturing a single attacking piece can therefore result in a score
890 // change far bigger than the value of the captured piece.
891 Value v = apply_weight(SafetyTable[attackUnits], WeightKingSafety[us]);
893 ei.mgValue -= sign * v;
895 if (us == p.side_to_move())
896 ei.futilityMargin += v;
901 // evaluate_passed_pawns() evaluates the passed pawns for both sides.
903 void evaluate_passed_pawns(const Position &pos, EvalInfo &ei) {
905 bool hasUnstoppable[2] = {false, false};
906 int movesToGo[2] = {100, 100};
908 for (Color us = WHITE; us <= BLACK; us++)
910 Color them = opposite_color(us);
911 Square ourKingSq = pos.king_square(us);
912 Square theirKingSq = pos.king_square(them);
913 Bitboard b = ei.pi->passed_pawns() & pos.pawns(us), b2, b3, b4;
917 Square s = pop_1st_bit(&b);
919 assert(pos.piece_on(s) == pawn_of_color(us));
920 assert(pos.pawn_is_passed(us, s));
922 int r = int(relative_rank(us, s) - RANK_2);
923 int tr = Max(0, r * (r - 1));
924 Square blockSq = s + pawn_push(us);
926 // Base bonus based on rank
927 Value mbonus = Value(20 * tr);
928 Value ebonus = Value(10 + r * r * 10);
930 // Adjust bonus based on king proximity
933 ebonus -= Value(square_distance(ourKingSq, blockSq) * 3 * tr);
934 ebonus -= Value(square_distance(ourKingSq, blockSq + pawn_push(us)) * 1 * tr);
935 ebonus += Value(square_distance(theirKingSq, blockSq) * 6 * tr);
937 // If the pawn is free to advance, increase bonus
938 if (pos.square_is_empty(blockSq))
940 b2 = squares_in_front_of(us, s);
941 b3 = b2 & ei.attacked_by(them);
942 b4 = b2 & ei.attacked_by(us);
944 // If there is an enemy rook or queen attacking the pawn from behind,
945 // add all X-ray attacks by the rook or queen.
946 if ( bit_is_set(ei.attacked_by(them,ROOK) | ei.attacked_by(them,QUEEN),s)
947 && (squares_behind(us, s) & pos.rooks_and_queens(them)))
950 if ((b2 & pos.pieces_of_color(them)) == EmptyBoardBB)
952 // There are no enemy pieces in the pawn's path! Are any of the
953 // squares in the pawn's path attacked by the enemy?
954 if (b3 == EmptyBoardBB)
955 // No enemy attacks, huge bonus!
956 ebonus += Value(tr * (b2 == b4 ? 17 : 15));
958 // OK, there are enemy attacks. Are those squares which are
959 // attacked by the enemy also attacked by us? If yes, big bonus
960 // (but smaller than when there are no enemy attacks), if no,
961 // somewhat smaller bonus.
962 ebonus += Value(tr * ((b3 & b4) == b3 ? 13 : 8));
966 // There are some enemy pieces in the pawn's path. While this is
967 // sad, we still assign a moderate bonus if all squares in the path
968 // which are either occupied by or attacked by enemy pieces are
969 // also attacked by us.
970 if (((b3 | (b2 & pos.pieces_of_color(them))) & ~b4) == EmptyBoardBB)
971 ebonus += Value(tr * 6);
973 // At last, add a small bonus when there are no *friendly* pieces
974 // in the pawn's path.
975 if ((b2 & pos.pieces_of_color(us)) == EmptyBoardBB)
980 // If the pawn is supported by a friendly pawn, increase bonus
981 b2 = pos.pawns(us) & neighboring_files_bb(s);
983 ebonus += Value(r * 20);
984 else if (pos.pawn_attacks(them, s) & b2)
985 ebonus += Value(r * 12);
987 // If the other side has only a king, check whether the pawn is
989 if (pos.non_pawn_material(them) == Value(0))
994 qsq = relative_square(us, make_square(square_file(s), RANK_8));
995 d = square_distance(s, qsq)
996 - square_distance(theirKingSq, qsq)
997 + (us != pos.side_to_move());
1001 int mtg = RANK_8 - relative_rank(us, s);
1002 int blockerCount = count_1s_max_15(squares_in_front_of(us,s) & pos.occupied_squares());
1003 mtg += blockerCount;
1007 hasUnstoppable[us] = true;
1008 movesToGo[us] = Min(movesToGo[us], mtg);
1012 // Rook pawns are a special case: They are sometimes worse, and
1013 // sometimes better than other passed pawns. It is difficult to find
1014 // good rules for determining whether they are good or bad. For now,
1015 // we try the following: Increase the value for rook pawns if the
1016 // other side has no pieces apart from a knight, and decrease the
1017 // value if the other side has a rook or queen.
1018 if (square_file(s) == FILE_A || square_file(s) == FILE_H)
1020 if( pos.non_pawn_material(them) <= KnightValueMidgame
1021 && pos.piece_count(them, KNIGHT) <= 1)
1022 ebonus += ebonus / 4;
1023 else if(pos.rooks_and_queens(them))
1024 ebonus -= ebonus / 4;
1027 // Add the scores for this pawn to the middle game and endgame eval.
1028 ei.mgValue += apply_weight(Sign[us] * mbonus, WeightPassedPawnsMidgame);
1029 ei.egValue += apply_weight(Sign[us] * ebonus, WeightPassedPawnsEndgame);
1033 // Does either side have an unstoppable passed pawn?
1034 if (hasUnstoppable[WHITE] && !hasUnstoppable[BLACK])
1035 ei.egValue += UnstoppablePawnValue - Value(0x40 * movesToGo[WHITE]);
1036 else if (hasUnstoppable[BLACK] && !hasUnstoppable[WHITE])
1037 ei.egValue -= UnstoppablePawnValue - Value(0x40 * movesToGo[BLACK]);
1038 else if (hasUnstoppable[BLACK] && hasUnstoppable[WHITE])
1040 // Both sides have unstoppable pawns! Try to find out who queens
1041 // first. We begin by transforming 'movesToGo' to the number of
1042 // plies until the pawn queens for both sides.
1043 movesToGo[WHITE] *= 2;
1044 movesToGo[BLACK] *= 2;
1045 movesToGo[pos.side_to_move()]--;
1047 // If one side queens at least three plies before the other, that
1049 if (movesToGo[WHITE] <= movesToGo[BLACK] - 3)
1050 ei.egValue += UnstoppablePawnValue - Value(0x40 * (movesToGo[WHITE]/2));
1051 else if(movesToGo[BLACK] <= movesToGo[WHITE] - 3)
1052 ei.egValue -= UnstoppablePawnValue - Value(0x40 * (movesToGo[BLACK]/2));
1054 // We could also add some rules about the situation when one side
1055 // queens exactly one ply before the other: Does the first queen
1056 // check the opponent's king, or attack the opponent's queening square?
1057 // This is slightly tricky to get right, because it is possible that
1058 // the opponent's king has moved somewhere before the first pawn queens.
1063 // evaluate_trapped_bishop_a7h7() determines whether a bishop on a7/h7
1064 // (a2/h2 for black) is trapped by enemy pawns, and assigns a penalty
1067 void evaluate_trapped_bishop_a7h7(const Position &pos, Square s, Color us,
1069 assert(square_is_ok(s));
1070 assert(pos.piece_on(s) == bishop_of_color(us));
1072 Square b6 = relative_square(us, (square_file(s) == FILE_A) ? SQ_B6 : SQ_G6);
1073 Square b8 = relative_square(us, (square_file(s) == FILE_A) ? SQ_B8 : SQ_G8);
1075 if ( pos.piece_on(b6) == pawn_of_color(opposite_color(us))
1076 && pos.see(s, b6) < 0
1077 && pos.see(s, b8) < 0)
1079 ei.mgValue -= Sign[us] * TrappedBishopA7H7Penalty;
1080 ei.egValue -= Sign[us] * TrappedBishopA7H7Penalty;
1085 // evaluate_trapped_bishop_a1h1() determines whether a bishop on a1/h1
1086 // (a8/h8 for black) is trapped by a friendly pawn on b2/g2 (b7/g7 for
1087 // black), and assigns a penalty if it is. This pattern can obviously
1088 // only occur in Chess960 games.
1090 void evaluate_trapped_bishop_a1h1(const Position &pos, Square s, Color us,
1092 Piece pawn = pawn_of_color(us);
1096 assert(square_is_ok(s));
1097 assert(pos.piece_on(s) == bishop_of_color(us));
1099 if (square_file(s) == FILE_A)
1101 b2 = relative_square(us, SQ_B2);
1102 b3 = relative_square(us, SQ_B3);
1103 c3 = relative_square(us, SQ_C3);
1107 b2 = relative_square(us, SQ_G2);
1108 b3 = relative_square(us, SQ_G3);
1109 c3 = relative_square(us, SQ_F3);
1112 if (pos.piece_on(b2) == pawn)
1116 if (!pos.square_is_empty(b3))
1117 penalty = 2*TrappedBishopA1H1Penalty;
1118 else if (pos.piece_on(c3) == pawn)
1119 penalty = TrappedBishopA1H1Penalty;
1121 penalty = TrappedBishopA1H1Penalty / 2;
1123 ei.mgValue -= Sign[us] * penalty;
1124 ei.egValue -= Sign[us] * penalty;
1129 // evaluate_space() computes the space evaluation for a given side. The
1130 // space evaluation is a simple bonus based on the number of safe squares
1131 // available for minor pieces on the central four files on ranks 2--4. Safe
1132 // squares one, two or three squares behind a friendly pawn are counted
1133 // twice. Finally, the space bonus is scaled by a weight taken from the
1134 // material hash table.
1136 void evaluate_space(const Position &pos, Color us, EvalInfo &ei) {
1138 Color them = opposite_color(us);
1140 // Find the safe squares for our pieces inside the area defined by
1141 // SpaceMask[us]. A square is unsafe it is attacked by an enemy
1142 // pawn, or if it is undefended and attacked by an enemy piece.
1144 Bitboard safeSquares = SpaceMask[us]
1146 & ~ei.attacked_by(them, PAWN)
1147 & ~(~ei.attacked_by(us) & ei.attacked_by(them));
1149 // Find all squares which are at most three squares behind some friendly
1151 Bitboard behindFriendlyPawns = pos.pawns(us);
1154 behindFriendlyPawns |= (behindFriendlyPawns >> 8);
1155 behindFriendlyPawns |= (behindFriendlyPawns >> 16);
1159 behindFriendlyPawns |= (behindFriendlyPawns << 8);
1160 behindFriendlyPawns |= (behindFriendlyPawns << 16);
1163 int space = count_1s_max_15(safeSquares)
1164 + count_1s_max_15(behindFriendlyPawns & safeSquares);
1166 ei.mgValue += Sign[us] * apply_weight(Value(space * ei.mi->space_weight()), WeightSpace);
1170 // apply_weight() applies an evaluation weight to a value
1172 inline Value apply_weight(Value v, int w) {
1173 return (v*w) / 0x100;
1177 // scale_by_game_phase() interpolates between a middle game and an endgame
1178 // score, based on game phase. It also scales the return value by a
1179 // ScaleFactor array.
1181 Value scale_by_game_phase(Value mv, Value ev, Phase ph, const ScaleFactor sf[]) {
1183 assert(mv > -VALUE_INFINITE && mv < VALUE_INFINITE);
1184 assert(ev > -VALUE_INFINITE && ev < VALUE_INFINITE);
1185 assert(ph >= PHASE_ENDGAME && ph <= PHASE_MIDGAME);
1187 ev = apply_scale_factor(ev, sf[(ev > Value(0) ? WHITE : BLACK)]);
1189 Value result = Value(int((mv * ph + ev * (128 - ph)) / 128));
1190 return Value(int(result) & ~(GrainSize - 1));
1194 // count_1s_8bit() counts the number of nonzero bits in the 8 least
1195 // significant bits of a Bitboard. This function is used by the king
1196 // shield evaluation.
1198 int count_1s_8bit(Bitboard b) {
1199 return int(BitCount8Bit[b & 0xFF]);
1203 // compute_weight() computes the value of an evaluation weight, by combining
1204 // an UCI-configurable weight with an internal weight.
1206 int compute_weight(int uciWeight, int internalWeight) {
1208 uciWeight = (uciWeight * 0x100) / 100;
1209 return (uciWeight * internalWeight) / 0x100;
1213 // helper used in read_weights()
1214 int weight_option(const std::string& opt, int weight) {
1216 return compute_weight(get_option_value_int(opt), weight);
1220 // init_safety() initizes the king safety evaluation, based on UCI
1221 // parameters. It is called from read_weights().
1223 void init_safety() {
1225 QueenContactCheckBonus = get_option_value_int("Queen Contact Check Bonus");
1226 QueenCheckBonus = get_option_value_int("Queen Check Bonus");
1227 RookCheckBonus = get_option_value_int("Rook Check Bonus");
1228 BishopCheckBonus = get_option_value_int("Bishop Check Bonus");
1229 KnightCheckBonus = get_option_value_int("Knight Check Bonus");
1230 DiscoveredCheckBonus = get_option_value_int("Discovered Check Bonus");
1231 MateThreatBonus = get_option_value_int("Mate Threat Bonus");
1233 int maxSlope = get_option_value_int("King Safety Max Slope");
1234 int peak = get_option_value_int("King Safety Max Value") * 256 / 100;
1235 double a = get_option_value_int("King Safety Coefficient") / 100.0;
1236 double b = get_option_value_int("King Safety X Intercept");
1237 bool quad = (get_option_value_string("King Safety Curve") == "Quadratic");
1238 bool linear = (get_option_value_string("King Safety Curve") == "Linear");
1240 for (int i = 0; i < 100; i++)
1243 SafetyTable[i] = Value(0);
1245 SafetyTable[i] = Value((int)(a * (i - b) * (i - b)));
1247 SafetyTable[i] = Value((int)(100 * a * (i - b)));
1250 for (int i = 0; i < 100; i++)
1252 if (SafetyTable[i+1] - SafetyTable[i] > maxSlope)
1253 for (int j = i + 1; j < 100; j++)
1254 SafetyTable[j] = SafetyTable[j-1] + Value(maxSlope);
1256 if (SafetyTable[i] > Value(peak))
1257 SafetyTable[i] = Value(peak);