X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fevaluate.cpp;h=6f2dd69ba33d7a5986fe99be7d70493d29023c76;hp=2698c813dfab118e78a37d1d70d8d1584c4d1e59;hb=4006f2c9132db034a27a94be33070d6aaab75b24;hpb=d7a2d5a44588676abf9b49e35a5a567fd57ec3b0 diff --git a/src/evaluate.cpp b/src/evaluate.cpp index 2698c813..6f2dd69b 100644 --- a/src/evaluate.cpp +++ b/src/evaluate.cpp @@ -35,7 +35,7 @@ namespace Trace { enum Tracing { NO_TRACE, TRACE }; enum Term { // The first 8 entries are reserved for PieceType - MATERIAL = 8, IMBALANCE, MOBILITY, THREAT, PASSED, SPACE, INITIATIVE, TOTAL, TERM_NB + MATERIAL = 8, IMBALANCE, MOBILITY, THREAT, PASSED, SPACE, WINNABLE, TOTAL, TERM_NB }; Score scores[TERM_NB][COLOR_NB]; @@ -59,7 +59,7 @@ namespace Trace { std::ostream& operator<<(std::ostream& os, Term t) { - if (t == MATERIAL || t == IMBALANCE || t == INITIATIVE || t == TOTAL) + if (t == MATERIAL || t == IMBALANCE || t == WINNABLE || t == TOTAL) os << " ---- ----" << " | " << " ---- ----"; else os << scores[t][WHITE] << " | " << scores[t][BLACK]; @@ -80,35 +80,47 @@ namespace { // KingAttackWeights[PieceType] contains king attack weights by piece type constexpr int KingAttackWeights[PIECE_TYPE_NB] = { 0, 0, 81, 52, 44, 10 }; - // Penalties for enemy's safe checks - constexpr int QueenSafeCheck = 780; - constexpr int RookSafeCheck = 1080; - constexpr int BishopSafeCheck = 635; - constexpr int KnightSafeCheck = 790; + // SafeCheck[PieceType][single/multiple] contains safe check bonus by piece type, + // higher if multiple safe checks are possible for that piece type. + constexpr int SafeCheck[][2] = { + {}, {}, {792, 1283}, {645, 967}, {1084, 1897}, {772, 1119} + }; #define S(mg, eg) make_score(mg, eg) // MobilityBonus[PieceType-2][attacked] contains bonuses for middle and end game, // indexed by piece type and number of attacked squares in the mobility area. constexpr Score MobilityBonus[][32] = { - { S(-62,-81), S(-53,-56), S(-12,-30), S( -4,-14), S( 3, 8), S( 13, 15), // Knight - S( 22, 23), S( 28, 27), S( 33, 33) }, + { S(-62,-81), S(-53,-56), S(-12,-31), S( -4,-16), S( 3, 5), S( 13, 11), // Knight + S( 22, 17), S( 28, 20), S( 33, 25) }, { S(-48,-59), S(-20,-23), S( 16, -3), S( 26, 13), S( 38, 24), S( 51, 42), // Bishop S( 55, 54), S( 63, 57), S( 63, 65), S( 68, 73), S( 81, 78), S( 81, 86), S( 91, 88), S( 98, 97) }, - { S(-58,-76), S(-27,-18), S(-15, 28), S(-10, 55), S( -5, 69), S( -2, 82), // Rook - S( 9,112), S( 16,118), S( 30,132), S( 29,142), S( 32,155), S( 38,165), - S( 46,166), S( 48,169), S( 58,171) }, - { S(-39,-36), S(-21,-15), S( 3, 8), S( 3, 18), S( 14, 34), S( 22, 54), // Queen - S( 28, 61), S( 41, 73), S( 43, 79), S( 48, 92), S( 56, 94), S( 60,104), - S( 60,113), S( 66,120), S( 67,123), S( 70,126), S( 71,133), S( 73,136), - S( 79,140), S( 88,143), S( 88,148), S( 99,166), S(102,170), S(102,175), - S(106,184), S(109,191), S(113,206), S(116,212) } + { S(-60,-78), S(-20,-17), S( 2, 23), S( 3, 39), S( 3, 70), S( 11, 99), // Rook + S( 22,103), S( 31,121), S( 40,134), S( 40,139), S( 41,158), S( 48,164), + S( 57,168), S( 57,169), S( 62,172) }, + { S(-30,-48), S(-12,-30), S( -8, -7), S( -9, 19), S( 20, 40), S( 23, 55), // Queen + S( 23, 59), S( 35, 75), S( 38, 78), S( 53, 96), S( 64, 96), S( 65,100), + S( 65,121), S( 66,127), S( 67,131), S( 67,133), S( 72,136), S( 72,141), + S( 77,147), S( 79,150), S( 93,151), S(108,168), S(108,168), S(108,171), + S(110,182), S(114,182), S(114,192), S(116,219) } + }; + + // KingProtector[knight/bishop] contains penalty for each distance unit to own king + constexpr Score KingProtector[] = { S(8, 9), S(6, 9) }; + + // Outpost[knight/bishop] contains bonuses for each knight or bishop occupying a + // pawn protected square on rank 4 to 6 which is also safe from a pawn attack. + constexpr Score Outpost[] = { S(56, 36), S(30, 23) }; + + // PassedRank[Rank] contains a bonus according to the rank of a passed pawn + constexpr Score PassedRank[RANK_NB] = { + S(0, 0), S(10, 28), S(17, 33), S(15, 41), S(62, 72), S(168, 177), S(276, 260) }; // RookOnFile[semiopen/open] contains bonuses for each rook when there is // no (friendly) pawn on the rook file. - constexpr Score RookOnFile[] = { S(21, 4), S(47, 25) }; + constexpr Score RookOnFile[] = { S(19, 7), S(48, 29) }; // ThreatByMinor/ByRook[attacked PieceType] contains bonuses according to // which piece type attacks which one. Attacks on lesser pieces which are @@ -118,35 +130,34 @@ namespace { }; constexpr Score ThreatByRook[PIECE_TYPE_NB] = { - S(0, 0), S(2, 44), S(36, 71), S(36, 61), S(0, 38), S(51, 38) - }; - - // PassedRank[Rank] contains a bonus according to the rank of a passed pawn - constexpr Score PassedRank[RANK_NB] = { - S(0, 0), S(10, 28), S(17, 33), S(15, 41), S(62, 72), S(168, 177), S(276, 260) + S(0, 0), S(3, 46), S(37, 68), S(42, 60), S(0, 38), S(58, 41) }; // Assorted bonuses and penalties + constexpr Score BishopOnKingRing = S( 24, 0); constexpr Score BishopPawns = S( 3, 7); + constexpr Score BishopXRayPawns = S( 4, 5); constexpr Score CorneredBishop = S( 50, 50); constexpr Score FlankAttacks = S( 8, 0); constexpr Score Hanging = S( 69, 36); - constexpr Score KingProtector = S( 7, 8); - constexpr Score KnightOnQueen = S( 16, 12); + constexpr Score KnightOnQueen = S( 16, 11); constexpr Score LongDiagonalBishop = S( 45, 0); constexpr Score MinorBehindPawn = S( 18, 3); - constexpr Score Outpost = S( 30, 21); constexpr Score PassedFile = S( 11, 8); constexpr Score PawnlessFlank = S( 17, 95); + constexpr Score QueenInfiltration = S( -2, 14); + constexpr Score ReachableOutpost = S( 31, 22); constexpr Score RestrictedPiece = S( 7, 7); - constexpr Score RookOnQueenFile = S( 7, 6); - constexpr Score SliderOnQueen = S( 59, 18); + constexpr Score RookOnKingRing = S( 16, 0); + constexpr Score RookOnQueenFile = S( 6, 11); + constexpr Score SliderOnQueen = S( 60, 18); constexpr Score ThreatByKing = S( 24, 89); constexpr Score ThreatByPawnPush = S( 48, 39); constexpr Score ThreatBySafePawn = S(173, 94); - constexpr Score TrappedRook = S( 52, 10); - constexpr Score WeakQueen = S( 49, 15); + constexpr Score TrappedRook = S( 55, 13); constexpr Score WeakQueenProtection = S( 14, 0); + constexpr Score WeakQueen = S( 56, 15); + #undef S @@ -167,8 +178,7 @@ namespace { template Score threats() const; template Score passed() const; template Score space() const; - ScaleFactor scale_factor(Value eg) const; - Score initiative(Score score) const; + Value winnable(Score score) const; const Position& pos; Material::Entry* me; @@ -210,6 +220,7 @@ namespace { // Evaluation::initialize() computes king and pawn attacks, and the king ring // bitboard for a given color. This is done at the beginning of the evaluation. + template template void Evaluation::initialize() { @@ -230,7 +241,7 @@ namespace { mobilityArea[Us] = ~(b | pos.pieces(Us, KING, QUEEN) | pos.blockers_for_king(Us) | pe->pawn_attacks(Them)); // Initialize attackedBy[] for king and pawns - attackedBy[Us][KING] = pos.attacks_from(ksq); + attackedBy[Us][KING] = attacks_bb(ksq); attackedBy[Us][PAWN] = pe->pawn_attacks(Us); attackedBy[Us][ALL_PIECES] = attackedBy[Us][KING] | attackedBy[Us][PAWN]; attackedBy2[Us] = dblAttackByPawn | (attackedBy[Us][KING] & attackedBy[Us][PAWN]); @@ -238,7 +249,7 @@ namespace { // Init our king safety tables Square s = make_square(Utility::clamp(file_of(ksq), FILE_B, FILE_G), Utility::clamp(rank_of(ksq), RANK_2, RANK_7)); - kingRing[Us] = PseudoAttacks[KING][s] | s; + kingRing[Us] = attacks_bb(s) | s; kingAttackersCount[Them] = popcount(kingRing[Us] & pe->pawn_attacks(Them)); kingAttacksCount[Them] = kingAttackersWeight[Them] = 0; @@ -249,6 +260,7 @@ namespace { // Evaluation::pieces() scores pieces of a given color and type + template template Score Evaluation::pieces() { @@ -268,10 +280,10 @@ namespace { // Find attacked squares, including x-ray attacks for bishops and rooks b = Pt == BISHOP ? attacks_bb(s, pos.pieces() ^ pos.pieces(QUEEN)) : Pt == ROOK ? attacks_bb< ROOK>(s, pos.pieces() ^ pos.pieces(QUEEN) ^ pos.pieces(Us, ROOK)) - : pos.attacks_from(s); + : attacks_bb(s, pos.pieces()); if (pos.blockers_for_king(Us) & s) - b &= LineBB[pos.square(Us)][s]; + b &= line_bb(pos.square(Us), s); attackedBy2[Us] |= attackedBy[Us][ALL_PIECES] & b; attackedBy[Us][Pt] |= b; @@ -284,6 +296,12 @@ namespace { kingAttacksCount[Us] += popcount(b & attackedBy[Them][KING]); } + else if (Pt == ROOK && (file_bb(s) & kingRing[Them])) + score += RookOnKingRing; + + else if (Pt == BISHOP && (attacks_bb(s, pos.pieces(PAWN)) & kingRing[Them])) + score += BishopOnKingRing; + int mob = popcount(b & mobilityArea[Us]); mobility[Us] += MobilityBonus[Pt - 2][mob]; @@ -293,21 +311,20 @@ namespace { // Bonus if piece is on an outpost square or can reach one bb = OutpostRanks & attackedBy[Us][PAWN] & ~pe->pawn_attacks_span(Them); if (bb & s) - score += Outpost * (Pt == KNIGHT ? 2 : 1); - + score += Outpost[Pt == BISHOP]; else if (Pt == KNIGHT && bb & b & ~pos.pieces(Us)) - score += Outpost; + score += ReachableOutpost; // Bonus for a knight or bishop shielded by pawn if (shift(pos.pieces(PAWN)) & s) score += MinorBehindPawn; // Penalty if the piece is far from the king - score -= KingProtector * distance(pos.square(Us), s); + score -= KingProtector[Pt == BISHOP] * distance(pos.square(Us), s); if (Pt == BISHOP) { - // Penalty according to number of pawns on the same color square as the + // Penalty according to the number of our pawns on the same color square as the // bishop, bigger when the center files are blocked with pawns and smaller // when the bishop is outside the pawn chain. Bitboard blocked = pos.pieces(Us, PAWN) & shift(pos.pieces()); @@ -315,6 +332,9 @@ namespace { score -= BishopPawns * pos.pawns_on_same_color_squares(Us, s) * (!(attackedBy[Us][PAWN] & s) + popcount(blocked & CenterFiles)); + // Penalty for all enemy pawns x-rayed + score -= BishopXRayPawns * popcount(attacks_bb(s) & pos.pieces(Them, PAWN)); + // Bonus for bishop on a long diagonal which can "see" both center squares if (more_than_one(attacks_bb(s, pos.pieces(PAWN)) & Center)) score += LongDiagonalBishop; @@ -359,6 +379,10 @@ namespace { Bitboard queenPinners; if (pos.slider_blockers(pos.pieces(Them, ROOK, BISHOP), s, queenPinners)) score -= WeakQueen; + + // Bonus for queen on weak square in enemy camp + if (relative_rank(Us, s) > RANK_4 && (~pe->pawn_attacks_span(Them) & s)) + score += QueenInfiltration; } } if (T) @@ -369,6 +393,7 @@ namespace { // Evaluation::king() assigns bonuses and penalties to a king of a given color + template template Score Evaluation::king() const { @@ -397,41 +422,33 @@ namespace { b2 = attacks_bb(ksq, pos.pieces() ^ pos.pieces(Us, QUEEN)); // Enemy rooks checks - rookChecks = b1 & safe & attackedBy[Them][ROOK]; - + rookChecks = b1 & attackedBy[Them][ROOK] & safe; if (rookChecks) - kingDanger += RookSafeCheck; + kingDanger += SafeCheck[ROOK][more_than_one(rookChecks)]; else unsafeChecks |= b1 & attackedBy[Them][ROOK]; - // Enemy queen safe checks: we count them only if they are from squares from - // which we can't give a rook check, because rook checks are more valuable. - queenChecks = (b1 | b2) - & attackedBy[Them][QUEEN] - & safe - & ~attackedBy[Us][QUEEN] - & ~rookChecks; - + // Enemy queen safe checks: count them only if the checks are from squares from + // which opponent cannot give a rook check, because rook checks are more valuable. + queenChecks = (b1 | b2) & attackedBy[Them][QUEEN] & safe + & ~(attackedBy[Us][QUEEN] | rookChecks); if (queenChecks) - kingDanger += QueenSafeCheck; + kingDanger += SafeCheck[QUEEN][more_than_one(queenChecks)]; - // Enemy bishops checks: we count them only if they are from squares from - // which we can't give a queen check, because queen checks are more valuable. - bishopChecks = b2 - & attackedBy[Them][BISHOP] - & safe + // Enemy bishops checks: count them only if they are from squares from which + // opponent cannot give a queen check, because queen checks are more valuable. + bishopChecks = b2 & attackedBy[Them][BISHOP] & safe & ~queenChecks; - if (bishopChecks) - kingDanger += BishopSafeCheck; + kingDanger += SafeCheck[BISHOP][more_than_one(bishopChecks)]; + else unsafeChecks |= b2 & attackedBy[Them][BISHOP]; // Enemy knights checks - knightChecks = pos.attacks_from(ksq) & attackedBy[Them][KNIGHT]; - + knightChecks = attacks_bb(ksq) & attackedBy[Them][KNIGHT]; if (knightChecks & safe) - kingDanger += KnightSafeCheck; + kingDanger += SafeCheck[KNIGHT][more_than_one(knightChecks & safe)]; else unsafeChecks |= knightChecks; @@ -441,7 +458,7 @@ namespace { b2 = b1 & attackedBy2[Them]; b3 = attackedBy[Us][ALL_PIECES] & KingFlank[file_of(ksq)] & Camp; - int kingFlankAttack = popcount(b1) + popcount(b2); + int kingFlankAttack = popcount(b1) + popcount(b2); int kingFlankDefense = popcount(b3); kingDanger += kingAttackersCount[Them] * kingAttackersWeight[Them] @@ -477,6 +494,7 @@ namespace { // Evaluation::threats() assigns bonuses according to the types of the // attacking and the attacked pieces. + template template Score Evaluation::threats() const { @@ -554,12 +572,12 @@ namespace { Square s = pos.square(Them); safe = mobilityArea[Us] & ~stronglyProtected; - b = attackedBy[Us][KNIGHT] & pos.attacks_from(s); + b = attackedBy[Us][KNIGHT] & attacks_bb(s); score += KnightOnQueen * popcount(b & safe); - b = (attackedBy[Us][BISHOP] & pos.attacks_from(s)) - | (attackedBy[Us][ROOK ] & pos.attacks_from(s)); + b = (attackedBy[Us][BISHOP] & attacks_bb(s, pos.pieces())) + | (attackedBy[Us][ROOK ] & attacks_bb(s, pos.pieces())); score += SliderOnQueen * popcount(b & safe & attackedBy2[Us]); } @@ -584,25 +602,22 @@ namespace { return std::min(distance(pos.square(c), s), 5); }; - Bitboard b, bb, squaresToQueen, unsafeSquares, candidatePassers, leverable; + Bitboard b, bb, squaresToQueen, unsafeSquares, blockedPassers, helpers; Score score = SCORE_ZERO; b = pe->passed_pawns(Us); - candidatePassers = b & shift(pos.pieces(Them, PAWN)); - if (candidatePassers) + blockedPassers = b & shift(pos.pieces(Them, PAWN)); + if (blockedPassers) { - // Can we lever the blocker of a candidate passer? - leverable = shift(pos.pieces(Us, PAWN)) - & ~pos.pieces(Them) - & (~attackedBy2[Them] | attackedBy[Us][ALL_PIECES]) - & (~(attackedBy[Them][KNIGHT] | attackedBy[Them][BISHOP]) - | (attackedBy[Us ][KNIGHT] | attackedBy[Us ][BISHOP])); - - // Remove candidate otherwise - b &= ~candidatePassers - | shift(leverable) - | shift(leverable); + helpers = shift(pos.pieces(Us, PAWN)) + & ~pos.pieces(Them) + & (~attackedBy2[Them] | attackedBy[Us][ALL_PIECES]); + + // Remove blocked candidate passers that don't have help to pass + b &= ~blockedPassers + | shift(helpers) + | shift(helpers); } while (b) @@ -665,16 +680,15 @@ namespace { } - // Evaluation::space() computes the space evaluation for a given side. The - // space evaluation is a simple bonus based on the number of safe squares - // available for minor pieces on the central four files on ranks 2--4. Safe - // squares one, two or three squares behind a friendly pawn are counted - // twice. Finally, the space bonus is multiplied by a weight. The aim is to - // improve play on game opening. + // Evaluation::space() computes a space evaluation for a given side, aiming to improve game + // play in the opening. It is based on the number of safe squares on the 4 central files + // on ranks 2 to 4. Completely safe squares behind a friendly pawn are counted twice. + // Finally, the space bonus is multiplied by a weight which decreases according to occupancy. template template Score Evaluation::space() const { + // Early exit if, for example, both queens or 6 minor pieces have been exchanged if (pos.non_pawn_material() < SpaceThreshold) return SCORE_ZERO; @@ -695,7 +709,7 @@ namespace { behind |= shift(behind); int bonus = popcount(safe) + popcount(behind & safe & ~attackedBy[Them][ALL_PIECES]); - int weight = pos.count(Us) - 1; + int weight = pos.count(Us) - 3 + std::min(pe->blocked_count(), 9); Score score = make_score(bonus * weight * weight / 16, 0); if (T) @@ -705,12 +719,12 @@ namespace { } - // Evaluation::initiative() computes the initiative correction value - // for the position. It is a second order bonus/malus based on the - // known attacking/defending status of the players. + // Evaluation::winnable() adjusts the midgame and endgame score components, based on + // the known attacking/defending status of the players. The final value is derived + // by interpolation from the midgame and endgame values. template - Score Evaluation::initiative(Score score) const { + Value Evaluation::winnable(Score score) const { int outflanking = distance(pos.square(WHITE), pos.square(BLACK)) - distance(pos.square(WHITE), pos.square(BLACK)); @@ -721,12 +735,12 @@ namespace { bool almostUnwinnable = outflanking < 0 && !pawnsOnBothFlanks; - bool infiltration = rank_of(pos.square(WHITE)) > RANK_4 - || rank_of(pos.square(BLACK)) < RANK_5; + bool infiltration = rank_of(pos.square(WHITE)) > RANK_4 + || rank_of(pos.square(BLACK)) < RANK_5; // Compute the initiative bonus for the attacking side int complexity = 9 * pe->passed_count() - + 11 * pos.count() + + 12 * pos.count() + 9 * outflanking + 21 * pawnsOnBothFlanks + 24 * infiltration @@ -740,37 +754,52 @@ namespace { // Now apply the bonus: note that we find the attacking side by extracting the // sign of the midgame or endgame values, and that we carefully cap the bonus // so that the midgame and endgame scores do not change sign after the bonus. - int u = ((mg > 0) - (mg < 0)) * std::max(std::min(complexity + 50, 0), -abs(mg)); + int u = ((mg > 0) - (mg < 0)) * Utility::clamp(complexity + 50, -abs(mg), 0); int v = ((eg > 0) - (eg < 0)) * std::max(complexity, -abs(eg)); - if (T) - Trace::add(INITIATIVE, make_score(u, v)); - - return make_score(u, v); - } - - - // Evaluation::scale_factor() computes the scale factor for the winning side - - template - ScaleFactor Evaluation::scale_factor(Value eg) const { + mg += u; + eg += v; + // Compute the scale factor for the winning side Color strongSide = eg > VALUE_DRAW ? WHITE : BLACK; int sf = me->scale_factor(pos, strongSide); - // If scale is not already specific, scale down the endgame via general heuristics + // If scale factor is not already specific, scale down via general heuristics if (sf == SCALE_FACTOR_NORMAL) { - if ( pos.opposite_bishops() - && pos.non_pawn_material() == 2 * BishopValueMg) - sf = 22; + if (pos.opposite_bishops()) + { + if ( pos.non_pawn_material(WHITE) == BishopValueMg + && pos.non_pawn_material(BLACK) == BishopValueMg) + sf = 18 + 4 * popcount(pe->passed_pawns(strongSide)); + else + sf = 22 + 3 * pos.count(strongSide); + } + else if ( pos.non_pawn_material(WHITE) == RookValueMg + && pos.non_pawn_material(BLACK) == RookValueMg + && pos.count(strongSide) - pos.count(~strongSide) <= 1 + && bool(KingSide & pos.pieces(strongSide, PAWN)) != bool(QueenSide & pos.pieces(strongSide, PAWN)) + && (attackedBy[~strongSide][KING] & pos.pieces(~strongSide, PAWN))) + sf = 36; + else if (pos.count() == 1) + sf = 37 + 3 * (pos.count(WHITE) == 1 ? pos.count(BLACK) + pos.count(BLACK) + : pos.count(WHITE) + pos.count(WHITE)); else - sf = std::min(sf, 36 + (pos.opposite_bishops() ? 2 : 7) * pos.count(strongSide)); + sf = std::min(sf, 36 + 7 * pos.count(strongSide)); + } + + // Interpolate between the middlegame and (scaled by 'sf') endgame score + v = mg * int(me->game_phase()) + + eg * int(PHASE_MIDGAME - me->game_phase()) * ScaleFactor(sf) / SCALE_FACTOR_NORMAL; + v /= PHASE_MIDGAME; - sf = std::max(0, sf - (pos.rule50_count() - 12) / 4); + if (T) + { + Trace::add(WINNABLE, make_score(u, eg * ScaleFactor(sf) / SCALE_FACTOR_NORMAL - eg_value(score))); + Trace::add(TOTAL, make_score(mg, eg * ScaleFactor(sf) / SCALE_FACTOR_NORMAL)); } - return ScaleFactor(sf); + return Value(v); } @@ -806,11 +835,11 @@ namespace { return pos.side_to_move() == WHITE ? v : -v; // Main evaluation begins here - initialize(); initialize(); - // Pieces should be evaluated first (populate attack tables) + // Pieces evaluated first (also populates attackedBy, attackedBy2). + // Note that the order of evaluation of the terms is left unspecified. score += pieces() - pieces() + pieces() - pieces() + pieces() - pieces() @@ -818,19 +847,14 @@ namespace { score += mobility[WHITE] - mobility[BLACK]; + // More complex interactions that require fully populated attack bitboards score += king< WHITE>() - king< BLACK>() + threats() - threats() + passed< WHITE>() - passed< BLACK>() + space< WHITE>() - space< BLACK>(); - score += initiative(score); - - // Interpolate between a middlegame and a (scaled by 'sf') endgame score - ScaleFactor sf = scale_factor(eg_value(score)); - v = mg_value(score) * int(me->game_phase()) - + eg_value(score) * int(PHASE_MIDGAME - me->game_phase()) * sf / SCALE_FACTOR_NORMAL; - - v /= PHASE_MIDGAME; + // Derive single value from mg and eg parts of score + v = winnable(score); // In case of tracing add all remaining individual evaluation terms if (T) @@ -839,10 +863,18 @@ namespace { Trace::add(IMBALANCE, me->imbalance()); Trace::add(PAWN, pe->pawn_score(WHITE), pe->pawn_score(BLACK)); Trace::add(MOBILITY, mobility[WHITE], mobility[BLACK]); - Trace::add(TOTAL, score); } - return (pos.side_to_move() == WHITE ? v : -v) + Tempo; // Side to move point of view + // Evaluation grain + v = (v / 16) * 16; + + // Side to move point of view + v = (pos.side_to_move() == WHITE ? v : -v) + Tempo; + + // Damp down the evaluation linearly when shuffling + v = v * (100 - pos.rule50_count()) / 100; + + return v; } } // namespace @@ -890,11 +922,11 @@ std::string Eval::trace(const Position& pos) { << " Threats | " << Term(THREAT) << " Passed | " << Term(PASSED) << " Space | " << Term(SPACE) - << " Initiative | " << Term(INITIATIVE) + << " Winnable | " << Term(WINNABLE) << " ------------+-------------+-------------+------------\n" << " Total | " << Term(TOTAL); - ss << "\nTotal evaluation: " << to_cp(v) << " (white side)\n"; + ss << "\nFinal evaluation: " << to_cp(v) << " (white side)\n"; return ss.str(); }