X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fevaluate.cpp;h=bf90e08c0eeae5817ea427966f63fd74cb124d48;hp=5c9bc86addca4d870f26241fcaea0b99236fd568;hb=ed72a1e9ba37a9fa2674da8f46bb0597a1721c2d;hpb=600234f2e23d1244fd38a31ac08a77f00b85a087 diff --git a/src/evaluate.cpp b/src/evaluate.cpp index 5c9bc86a..bf90e08c 100644 --- a/src/evaluate.cpp +++ b/src/evaluate.cpp @@ -30,34 +30,50 @@ namespace { - namespace Tracing { + namespace Trace { enum Term { // First 8 entries are for PieceType MATERIAL = 8, IMBALANCE, MOBILITY, THREAT, PASSED, SPACE, TOTAL, TERM_NB }; - Score scores[COLOR_NB][TERM_NB]; + double scores[TERM_NB][COLOR_NB][PHASE_NB]; - std::ostream& operator<<(std::ostream& os, Term idx); + double to_cp(Value v) { return double(v) / PawnValueEg; } - double to_cp(Value v); - void write(int idx, Color c, Score s); - void write(int idx, Score w, Score b = SCORE_ZERO); - std::string do_trace(const Position& pos); + void add(int idx, Color c, Score s) { + scores[idx][c][MG] = to_cp(mg_value(s)); + scores[idx][c][EG] = to_cp(eg_value(s)); + } + + void add(int idx, Score w, Score b = SCORE_ZERO) { + add(idx, WHITE, w); add(idx, BLACK, b); + } + + std::ostream& operator<<(std::ostream& os, Term t) { + + if (t == MATERIAL || t == IMBALANCE || t == Term(PAWN) || t == TOTAL) + os << " --- --- | --- --- | "; + else + os << std::setw(5) << scores[t][WHITE][MG] << " " + << std::setw(5) << scores[t][WHITE][EG] << " | " + << std::setw(5) << scores[t][BLACK][MG] << " " + << std::setw(5) << scores[t][BLACK][EG] << " | "; + + os << std::setw(5) << scores[t][WHITE][MG] - scores[t][BLACK][MG] << " " + << std::setw(5) << scores[t][WHITE][EG] - scores[t][BLACK][EG] << " \n"; + + return os; + } } + using namespace Trace; // Struct EvalInfo contains various information computed and collected // by the evaluation functions. struct EvalInfo { - // Pointers to material and pawn hash table entries - Material::Entry* mi; - Pawns::Entry* pi; - // attackedBy[color][piece type] is a bitboard representing all squares - // attacked by a given color and piece type, attackedBy[color][ALL_PIECES] - // contains all squares attacked by the given color. + // attacked by a given color and piece type (can be also ALL_PIECES). Bitboard attackedBy[COLOR_NB][PIECE_TYPE_NB]; // kingRing[color] is the zone around the king which is considered @@ -86,6 +102,8 @@ namespace { int kingAdjacentZoneAttacksCount[COLOR_NB]; Bitboard pinnedPieces[COLOR_NB]; + Material::Entry* me; + Pawns::Entry* pi; }; @@ -93,7 +111,7 @@ namespace { enum { Mobility, PawnStructure, PassedPawns, Space, KingSafety }; const struct Weight { int mg, eg; } Weights[] = { - {289, 344}, {233, 201}, {221, 273}, {46, 0}, {322, 0} + {266, 334}, {214, 203}, {193, 262}, {47, 0}, {330, 0} }; Score operator*(Score s, const Weight& w) { @@ -109,55 +127,68 @@ namespace { // friendly pieces. const Score MobilityBonus[][32] = { {}, {}, - { S(-68,-49), S(-46,-33), S(-3,-12), S( 5, -4), S( 9, 11), S(15, 16), // Knights - S( 23, 27), S( 33, 28), S(37, 29) }, - { S(-49,-44), S(-23,-16), S(16, 1), S(29, 16), S(40, 25), S(51, 34), // Bishops - S( 55, 43), S( 61, 49), S(64, 51), S(68, 52), S(73, 55), S(75, 60), - S( 80, 65), S( 86, 66) }, - { S(-50,-57), S(-28,-22), S(-11, 7), S(-1, 29), S( 0, 39), S( 1, 46), // Rooks - S( 10, 66), S( 16, 79), S(22, 86), S(23,103), S(30,109), S(33,111), - S( 37,115), S( 38,119), S(48,124) }, - { S(-43,-30), S(-27,-15), S( 1, -5), S( 2, -3), S(14, 10), S(18, 24), // Queens - S( 20, 27), S( 33, 37), S(33, 38), S(34, 43), S(40, 46), S(43, 56), - S( 46, 61), S( 52, 63), S(52, 63), S(57, 65), S(60, 70), S(61, 74), - S( 67, 80), S( 76, 82), S(77, 88), S(82, 94), S(86, 95), S(90, 96), - S( 94, 99), S( 96,100), S(99,111), S(99,112) } + { S(-70,-52), S(-52,-37), S( -7,-17), S( 0, -6), S( 8, 5), S( 16, 9), // Knights + S( 23, 20), S( 31, 21), S( 36, 22) }, + { S(-49,-44), S(-22,-13), S( 16, 0), S( 27, 11), S( 38, 19), S( 52, 34), // Bishops + S( 56, 44), S( 65, 47), S( 67, 51), S( 73, 56), S( 81, 59), S( 83, 69), + S( 95, 72), S(100, 75) }, + { S(-49,-57), S(-22,-14), S(-10, 18), S( -5, 39), S( -4, 50), S( -2, 58), // Rooks + S( 6, 78), S( 11, 86), S( 17, 92), S( 19,103), S( 26,111), S( 27,115), + S( 36,119), S( 41,121), S( 50,122) }, + { S(-41,-24), S(-26, -8), S( 0, 6), S( 2, 14), S( 12, 27), S( 21, 40), // Queens + S( 22, 45), S( 37, 55), S( 40, 57), S( 43, 63), S( 50, 68), S( 52, 74), + S( 56, 80), S( 66, 84), S( 68, 85), S( 69, 88), S( 71, 92), S( 72, 94), + S( 80, 96), S( 89, 98), S( 94,101), S(102,113), S(106,114), S(107,116), + S(112,125), S(113,127), S(117,137), S(122,143) } }; // Outpost[knight/bishop][supported by pawn] contains bonuses for knights and // bishops outposts, bigger if outpost piece is supported by a pawn. const Score Outpost[][2] = { - { S(28, 7), S(42,11) }, // Knights - { S(12, 3), S(18, 5) } // Bishops + { S(42,11), S(63,17) }, // Knights + { S(18, 5), S(27, 8) } // Bishops }; - // Threat[defended/weak][minor/major attacking][attacked PieceType] contains + // ReachableOutpost[knight/bishop][supported by pawn] contains bonuses for + // knights and bishops which can reach an outpost square in one move, bigger + // if outpost square is supported by a pawn. + const Score ReachableOutpost[][2] = { + { S(21, 5), S(31, 8) }, // Knights + { S( 8, 2), S(13, 4) } // Bishops + }; + + // Threat[minor/rook][attacked PieceType] contains // bonuses according to which piece type attacks which one. - const Score Threat[][2][PIECE_TYPE_NB] = { - { { S(0, 0), S( 0, 0), S(19, 37), S(24, 37), S(44, 97), S(35,106) }, // Defended Minor - { S(0, 0), S( 0, 0), S( 9, 14), S( 9, 14), S( 7, 14), S(24, 48) } }, // Defended Major - { { S(0, 0), S( 0,32), S(33, 41), S(31, 50), S(41,100), S(35,104) }, // Weak Minor - { S(0, 0), S( 0,27), S(26, 57), S(26, 57), S(0 , 43), S(23, 51) } } // Weak Major + // Attacks on lesser pieces which are pawn defended are not considered. + const Score Threat[2][PIECE_TYPE_NB] = { + { S(0, 0), S(0, 33), S(45, 43), S(46, 47), S(72, 107), S(48,118) }, // Minor attacks + { S(0, 0), S(0, 25), S(40, 62), S(40, 59), S( 0, 34), S(35, 48) } // Rook attacks }; // ThreatenedByPawn[PieceType] contains a penalty according to which piece - // type is attacked by an enemy pawn. + // type is attacked by a pawn. const Score ThreatenedByPawn[PIECE_TYPE_NB] = { - S(0, 0), S(0, 0), S(107, 138), S(84, 122), S(114, 203), S(121, 217) + S(0, 0), S(0, 0), S(176, 139), S(131, 127), S(217, 218), S(203, 215) }; - // Passed[mg/eg][rank] contains midgame and endgame bonuses for passed pawns. + // Passed[mg/eg][Rank] contains midgame and endgame bonuses for passed pawns. // We don't use a Score because we process the two components independently. const Value Passed[][RANK_NB] = { { V(0), V( 1), V(34), V(90), V(214), V(328) }, { V(7), V(14), V(37), V(63), V(134), V(189) } }; - const Score ThreatenedByHangingPawn = S(40, 60); + // PassedFile[File] contains a bonus according to the file of a passed pawn. + const Score PassedFile[] = { + S( 12, 10), S( 3, 10), S( 1, -8), S(-27, -12), + S(-27, -12), S( 1, -8), S( 3, 10), S( 12, 10) + }; + + const Score ThreatenedByHangingPawn = S(70, 63); // Assorted bonuses and penalties used by evaluation - const Score KingOnOne = S( 2, 58); - const Score KingOnMany = S( 6,125); + const Score KingOnOne = S( 3, 62); + const Score KingOnMany = S( 9,138); const Score RookOnPawn = S( 7, 27); const Score RookOnOpenFile = S(43, 21); const Score RookOnSemiOpenFile = S(19, 10); @@ -165,9 +196,9 @@ namespace { const Score MinorBehindPawn = S(16, 0); const Score TrappedRook = S(92, 0); const Score Unstoppable = S( 0, 20); - const Score Hanging = S(31, 26); - const Score PawnAttackThreat = S(20, 20); - const Score PawnSafePush = S( 5, 5); + const Score Hanging = S(48, 28); + const Score PawnAttackThreat = S(31, 19); + const Score Checked = S(20, 20); // Penalty for a bishop on a1/h1 (a8/h8 for black) which is trapped by // a friendly pawn on b2/g2 (b7/g7 for black). This can obviously only @@ -177,15 +208,6 @@ namespace { #undef S #undef V - // SpaceMask[Color] contains the area of the board which is considered - // by the space evaluation. In the middlegame, each side is given a bonus - // based on how many squares inside this area are safe and available for - // friendly minor pieces. - const Bitboard SpaceMask[COLOR_NB] = { - (FileCBB | FileDBB | FileEBB | FileFBB) & (Rank2BB | Rank3BB | Rank4BB), - (FileCBB | FileDBB | FileEBB | FileFBB) & (Rank7BB | Rank6BB | Rank5BB) - }; - // King danger constants and variables. The king danger scores are looked-up // in KingDanger[]. Various little "meta-bonuses" measuring the strength // of the enemy attack are added up into an integer, which is used as an @@ -197,25 +219,25 @@ namespace { // Penalties for enemy's safe checks const int QueenContactCheck = 89; - const int RookContactCheck = 71; const int QueenCheck = 50; - const int RookCheck = 37; + const int RookCheck = 45; const int BishopCheck = 6; const int KnightCheck = 14; - // init_eval_info() initializes king bitboards for given color adding - // pawn attacks. To be done at the beginning of the evaluation. + // eval_init() initializes king and attack bitboards for given color + // adding pawn attacks. To be done at the beginning of the evaluation. template - void init_eval_info(const Position& pos, EvalInfo& ei) { + void eval_init(const Position& pos, EvalInfo& ei) { const Color Them = (Us == WHITE ? BLACK : WHITE); const Square Down = (Us == WHITE ? DELTA_S : DELTA_N); ei.pinnedPieces[Us] = pos.pinned_pieces(Us); - ei.attackedBy[Us][ALL_PIECES] = ei.attackedBy[Us][PAWN] = ei.pi->pawn_attacks(Us); Bitboard b = ei.attackedBy[Them][KING] = pos.attacks_from(pos.square(Them)); + ei.attackedBy[Them][ALL_PIECES] |= b; + ei.attackedBy[Us][ALL_PIECES] |= ei.attackedBy[Us][PAWN] = ei.pi->pawn_attacks(Us); // Init king safety tables only if we are going to use them if (pos.non_pawn_material(Us) >= QueenValueMg) @@ -230,17 +252,20 @@ namespace { } - // evaluate_pieces() assigns bonuses and penalties to the pieces of a given color - - template - Score evaluate_pieces(const Position& pos, EvalInfo& ei, Score* mobility, Bitboard* mobilityArea) { + // evaluate_pieces() assigns bonuses and penalties to the pieces of a given + // color and type. - Bitboard b; + template + Score evaluate_pieces(const Position& pos, EvalInfo& ei, Score* mobility, + const Bitboard* mobilityArea) { + Bitboard b, bb; Square s; Score score = SCORE_ZERO; const PieceType NextPt = (Us == WHITE ? Pt : PieceType(Pt + 1)); const Color Them = (Us == WHITE ? BLACK : WHITE); + const Bitboard OutpostRanks = (Us == WHITE ? Rank4BB | Rank5BB | Rank6BB + : Rank5BB | Rank4BB | Rank3BB); const Square* pl = pos.squares(Us); ei.attackedBy[Us][Pt] = 0; @@ -261,7 +286,7 @@ namespace { { ei.kingAttackersCount[Us]++; ei.kingAttackersWeight[Us] += KingAttackWeights[Pt]; - Bitboard bb = b & ei.attackedBy[Them][KING]; + bb = b & ei.attackedBy[Them][KING]; if (bb) ei.kingAdjacentZoneAttacksCount[Us] += popcount(bb); } @@ -277,10 +302,16 @@ namespace { if (Pt == BISHOP || Pt == KNIGHT) { - // Bonus for outpost square - if ( relative_rank(Us, s) >= RANK_4 - && !(pos.pieces(Them, PAWN) & pawn_attack_span(Us, s))) + // Bonus for outpost squares + bb = OutpostRanks & ~ei.pi->pawn_attacks_span(Them); + if (bb & s) score += Outpost[Pt == BISHOP][!!(ei.attackedBy[Us][PAWN] & s)]; + else + { + bb &= b & ~pos.pieces(Us); + if (bb) + score += ReachableOutpost[Pt == BISHOP][!!(ei.attackedBy[Us][PAWN] & bb)]; + } // Bonus when behind a pawn if ( relative_rank(Us, s) < RANK_5 @@ -333,22 +364,22 @@ namespace { } } - if (Trace) - Tracing::write(Pt, Us, score); + if (DoTrace) + Trace::add(Pt, Us, score); // Recursively call evaluate_pieces() of next piece type until KING excluded - return score - evaluate_pieces(pos, ei, mobility, mobilityArea); + return score - evaluate_pieces(pos, ei, mobility, mobilityArea); } template<> - Score evaluate_pieces(const Position&, EvalInfo&, Score*, Bitboard*) { return SCORE_ZERO; } + Score evaluate_pieces(const Position&, EvalInfo&, Score*, const Bitboard*) { return SCORE_ZERO; } template<> - Score evaluate_pieces(const Position&, EvalInfo&, Score*, Bitboard*) { return SCORE_ZERO; } + Score evaluate_pieces< true, WHITE, KING>(const Position&, EvalInfo&, Score*, const Bitboard*) { return SCORE_ZERO; } // evaluate_king() assigns bonuses and penalties to a king of a given color - template + template Score evaluate_king(const Position& pos, const EvalInfo& ei) { const Color Them = (Us == WHITE ? BLACK : WHITE); @@ -364,7 +395,7 @@ namespace { if (ei.kingAttackersCount[Them]) { // Find the attacked squares around the king which have no defenders - // apart from the king itself + // apart from the king itself. undefended = ei.attackedBy[Them][ALL_PIECES] & ei.attackedBy[Us][KING] & ~( ei.attackedBy[Us][PAWN] | ei.attackedBy[Us][KNIGHT] @@ -376,12 +407,12 @@ namespace { // number and types of the enemy's attacking pieces, the number of // attacked and undefended squares around our king and the quality of // the pawn shelter (current 'score' value). - attackUnits = std::min(74, ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) - + 8 * ei.kingAdjacentZoneAttacksCount[Them] - + 25 * popcount(undefended) - + 11 * (ei.pinnedPieces[Us] != 0) - - mg_value(score) / 8 - - !pos.count(Them) * 60; + attackUnits = std::min(72, ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) + + 9 * ei.kingAdjacentZoneAttacksCount[Them] + + 27 * popcount(undefended) + + 11 * !!ei.pinnedPieces[Us] + - 64 * !pos.count(Them) + - mg_value(score) / 8; // Analyse the enemy's safe queen contact checks. Firstly, find the // undefended squares around the king reachable by the enemy queen... @@ -390,29 +421,13 @@ namespace { { // ...and then remove squares not supported by another enemy piece b &= ei.attackedBy[Them][PAWN] | ei.attackedBy[Them][KNIGHT] - | ei.attackedBy[Them][BISHOP] | ei.attackedBy[Them][ROOK]; + | ei.attackedBy[Them][BISHOP] | ei.attackedBy[Them][ROOK] + | ei.attackedBy[Them][KING]; if (b) attackUnits += QueenContactCheck * popcount(b); } - // Analyse the enemy's safe rook contact checks. Firstly, find the - // undefended squares around the king reachable by the enemy rooks... - b = undefended & ei.attackedBy[Them][ROOK] & ~pos.pieces(Them); - - // Consider only squares where the enemy's rook gives check - b &= PseudoAttacks[ROOK][ksq]; - - if (b) - { - // ...and then remove squares not supported by another enemy piece - b &= ( ei.attackedBy[Them][PAWN] | ei.attackedBy[Them][KNIGHT] - | ei.attackedBy[Them][BISHOP]); - - if (b) - attackUnits += RookContactCheck * popcount(b); - } - // Analyse the enemy's safe distance checks for sliders and knights safe = ~(ei.attackedBy[Us][ALL_PIECES] | pos.pieces(Them)); @@ -422,30 +437,42 @@ namespace { // Enemy queen safe checks b = (b1 | b2) & ei.attackedBy[Them][QUEEN]; if (b) + { attackUnits += QueenCheck * popcount(b); + score -= Checked; + } // Enemy rooks safe checks b = b1 & ei.attackedBy[Them][ROOK]; if (b) + { attackUnits += RookCheck * popcount(b); + score -= Checked; + } // Enemy bishops safe checks b = b2 & ei.attackedBy[Them][BISHOP]; if (b) + { attackUnits += BishopCheck * popcount(b); + score -= Checked; + } // Enemy knights safe checks b = pos.attacks_from(ksq) & ei.attackedBy[Them][KNIGHT] & safe; if (b) + { attackUnits += KnightCheck * popcount(b); + score -= Checked; + } // Finally, extract the king danger score from the KingDanger[] // array and subtract the score from evaluation. score -= KingDanger[std::max(std::min(attackUnits, 399), 0)]; } - if (Trace) - Tracing::write(KING, Us, score); + if (DoTrace) + Trace::add(KING, Us, score); return score; } @@ -454,7 +481,7 @@ namespace { // evaluate_threats() assigns bonuses according to the type of attacking piece // and the type of attacked one. - template + template Score evaluate_threats(const Position& pos, const EvalInfo& ei) { const Color Them = (Us == WHITE ? BLACK : WHITE); @@ -464,8 +491,7 @@ namespace { const Bitboard TRank2BB = (Us == WHITE ? Rank2BB : Rank7BB); const Bitboard TRank7BB = (Us == WHITE ? Rank7BB : Rank2BB); - enum { Defended, Weak }; - enum { Minor, Major }; + enum { Minor, Rook }; Bitboard b, weak, defended, safeThreats; Score score = SCORE_ZERO; @@ -490,33 +516,21 @@ namespace { // Non-pawn enemies defended by a pawn defended = (pos.pieces(Them) ^ pos.pieces(Them, PAWN)) & ei.attackedBy[Them][PAWN]; - // Add a bonus according to the kind of attacking pieces - if (defended) - { - b = defended & (ei.attackedBy[Us][KNIGHT] | ei.attackedBy[Us][BISHOP]); - while (b) - score += Threat[Defended][Minor][type_of(pos.piece_on(pop_lsb(&b)))]; - - b = defended & (ei.attackedBy[Us][ROOK]); - while (b) - score += Threat[Defended][Major][type_of(pos.piece_on(pop_lsb(&b)))]; - } - // Enemies not defended by a pawn and under our attack weak = pos.pieces(Them) & ~ei.attackedBy[Them][PAWN] & ei.attackedBy[Us][ALL_PIECES]; // Add a bonus according to the kind of attacking pieces - if (weak) + if (defended | weak) { - b = weak & (ei.attackedBy[Us][KNIGHT] | ei.attackedBy[Us][BISHOP]); + b = (defended | weak) & (ei.attackedBy[Us][KNIGHT] | ei.attackedBy[Us][BISHOP]); while (b) - score += Threat[Weak][Minor][type_of(pos.piece_on(pop_lsb(&b)))]; + score += Threat[Minor][type_of(pos.piece_on(pop_lsb(&b)))]; - b = weak & (ei.attackedBy[Us][ROOK] | ei.attackedBy[Us][QUEEN]); + b = (pos.pieces(Them, QUEEN) | weak) & ei.attackedBy[Us][ROOK]; while (b) - score += Threat[Weak][Major][type_of(pos.piece_on(pop_lsb(&b)))]; + score += Threat[Rook ][type_of(pos.piece_on(pop_lsb(&b)))]; b = weak & ~ei.attackedBy[Them][ALL_PIECES]; if (b) @@ -527,7 +541,7 @@ namespace { score += more_than_one(b) ? KingOnMany : KingOnOne; } - // Add a small bonus for safe pawn pushes + // Bonus if some pawns can safely push and attack an enemy piece b = pos.pieces(Us, PAWN) & ~TRank7BB; b = shift_bb(b | (shift_bb(b & TRank2BB) & ~pos.pieces())); @@ -535,10 +549,6 @@ namespace { & ~ei.attackedBy[Them][PAWN] & (ei.attackedBy[Us][ALL_PIECES] | ~ei.attackedBy[Them][ALL_PIECES]); - if (b) - score += popcount(b) * PawnSafePush; - - // Add another bonus if the pawn push attacks an enemy piece b = (shift_bb(b) | shift_bb(b)) & pos.pieces(Them) & ~ei.attackedBy[Us][PAWN]; @@ -546,8 +556,8 @@ namespace { if (b) score += popcount(b) * PawnAttackThreat; - if (Trace) - Tracing::write(Tracing::THREAT, Us, score); + if (DoTrace) + Trace::add(THREAT, Us, score); return score; } @@ -555,7 +565,7 @@ namespace { // evaluate_passed_pawns() evaluates the passed pawns of the given color - template + template Score evaluate_passed_pawns(const Position& pos, const EvalInfo& ei) { const Color Them = (Us == WHITE ? BLACK : WHITE); @@ -606,7 +616,7 @@ namespace { // If there aren't any enemy attacks, assign a big bonus. Otherwise // assign a smaller bonus if the block square isn't attacked. - int k = !unsafeSquares ? 15 : !(unsafeSquares & blockSq) ? 9 : 0; + int k = !unsafeSquares ? 18 : !(unsafeSquares & blockSq) ? 8 : 0; // If the path to queen is fully defended, assign a big bonus. // Otherwise assign a smaller bonus if the block square is defended. @@ -625,11 +635,11 @@ namespace { if (pos.count(Us) < pos.count(Them)) ebonus += ebonus / 4; - score += make_score(mbonus, ebonus); + score += make_score(mbonus, ebonus) + PassedFile[file_of(s)]; } - if (Trace) - Tracing::write(Tracing::PASSED, Us, score * Weights[PassedPawns]); + if (DoTrace) + Trace::add(PASSED, Us, score * Weights[PassedPawns]); // Add the scores to the middlegame and endgame eval return score * Weights[PassedPawns]; @@ -646,11 +656,14 @@ namespace { Score evaluate_space(const Position& pos, const EvalInfo& ei) { const Color Them = (Us == WHITE ? BLACK : WHITE); + const Bitboard SpaceMask = + Us == WHITE ? (FileCBB | FileDBB | FileEBB | FileFBB) & (Rank2BB | Rank3BB | Rank4BB) + : (FileCBB | FileDBB | FileEBB | FileFBB) & (Rank7BB | Rank6BB | Rank5BB); // Find the safe squares for our pieces inside the area defined by - // SpaceMask[]. A square is unsafe if it is attacked by an enemy + // SpaceMask. A square is unsafe if it is attacked by an enemy // pawn, or if it is undefended and attacked by an enemy piece. - Bitboard safe = SpaceMask[Us] + Bitboard safe = SpaceMask & ~pos.pieces(Us, PAWN) & ~ei.attackedBy[Them][PAWN] & (ei.attackedBy[Us][ALL_PIECES] | ~ei.attackedBy[Them][ALL_PIECES]); @@ -660,10 +673,10 @@ namespace { behind |= (Us == WHITE ? behind >> 8 : behind << 8); behind |= (Us == WHITE ? behind >> 16 : behind << 16); - // Since SpaceMask[Us] is fully on our half of the board + // Since SpaceMask[Us] is fully on our half of the board... assert(unsigned(safe >> (Us == WHITE ? 32 : 0)) == 0); - // Count safe + (behind & safe) with a single popcount + // ...count safe + (behind & safe) with a single popcount int bonus = popcount((Us == WHITE ? safe << 32 : safe >> 32) | (behind & safe)); int weight = pos.count(Us) + pos.count(Us) + pos.count(Them) + pos.count(Them); @@ -672,93 +685,35 @@ namespace { } - // do_evaluate() is the evaluation entry point, called directly from evaluate() - - template - Value do_evaluate(const Position& pos) { - - assert(!pos.checkers()); - - EvalInfo ei; - Score score, mobility[2] = { SCORE_ZERO, SCORE_ZERO }; - - // Initialize score by reading the incrementally updated scores included - // in the position object (material + piece square tables). - // Score is computed from the point of view of white. - score = pos.psq_score(); - - // Probe the material hash table - ei.mi = Material::probe(pos); - score += ei.mi->imbalance(); - - // If we have a specialized evaluation function for the current material - // configuration, call it and return. - if (ei.mi->specialized_eval_exists()) - return ei.mi->evaluate(pos); - - // Probe the pawn hash table - ei.pi = Pawns::probe(pos); - score += ei.pi->pawns_score() * Weights[PawnStructure]; - - // Initialize attack and king safety bitboards - init_eval_info(pos, ei); - init_eval_info(pos, ei); + // evaluate_initiative() computes the initiative correction value for the + // position, i.e. second order bonus/malus based on the known attacking/defending + // status of the players. + Score evaluate_initiative(const Position& pos, int asymmetry, Value eg) { - ei.attackedBy[WHITE][ALL_PIECES] |= ei.attackedBy[WHITE][KING]; - ei.attackedBy[BLACK][ALL_PIECES] |= ei.attackedBy[BLACK][KING]; + int kingDistance = distance(pos.square(WHITE), pos.square(BLACK)); + int pawns = pos.count(WHITE) + pos.count(BLACK); - // Pawns blocked or on ranks 2 and 3. Will be excluded from the mobility area - Bitboard blockedPawns[] = { - pos.pieces(WHITE, PAWN) & (shift_bb(pos.pieces()) | Rank2BB | Rank3BB), - pos.pieces(BLACK, PAWN) & (shift_bb(pos.pieces()) | Rank7BB | Rank6BB) - }; - - // Do not include in mobility squares protected by enemy pawns, or occupied - // by our blocked pawns or king. - Bitboard mobilityArea[] = { - ~(ei.attackedBy[BLACK][PAWN] | blockedPawns[WHITE] | pos.square(WHITE)), - ~(ei.attackedBy[WHITE][PAWN] | blockedPawns[BLACK] | pos.square(BLACK)) - }; - - // Evaluate pieces and mobility - score += evaluate_pieces(pos, ei, mobility, mobilityArea); - score += (mobility[WHITE] - mobility[BLACK]) * Weights[Mobility]; - - // Evaluate kings after all other pieces because we need complete attack - // information when computing the king safety evaluation. - score += evaluate_king(pos, ei) - - evaluate_king(pos, ei); - - // Evaluate tactical threats, we need full attack information including king - score += evaluate_threats(pos, ei) - - evaluate_threats(pos, ei); + // Compute the initiative bonus for the attacking side + int initiative = 8 * (pawns + asymmetry + kingDistance - 15); - // Evaluate passed pawns, we need full attack information including king - score += evaluate_passed_pawns(pos, ei) - - evaluate_passed_pawns(pos, ei); + // Now apply the bonus: note that we find the attacking side by extracting + // the sign of the endgame value, and that we carefully cap the bonus so + // that the endgame score will never be divided by more than two. + int value = ((eg > 0) - (eg < 0)) * std::max(initiative, -abs(eg / 2)); - // If both sides have only pawns, score for potential unstoppable pawns - if (!pos.non_pawn_material(WHITE) && !pos.non_pawn_material(BLACK)) - { - Bitboard b; - if ((b = ei.pi->passed_pawns(WHITE)) != 0) - score += int(relative_rank(WHITE, frontmost_sq(WHITE, b))) * Unstoppable; + return make_score(0, value); + } - if ((b = ei.pi->passed_pawns(BLACK)) != 0) - score -= int(relative_rank(BLACK, frontmost_sq(BLACK, b))) * Unstoppable; - } - // Evaluate space for both sides, only during opening - if (pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) >= 11756) - score += (evaluate_space(pos, ei) - evaluate_space(pos, ei)) * Weights[Space]; + // evaluate_scale_factor() computes the scale factor for the winning side + ScaleFactor evaluate_scale_factor(const Position& pos, const EvalInfo& ei, Score score) { - // Scale winning side if position is more drawish than it appears Color strongSide = eg_value(score) > VALUE_DRAW ? WHITE : BLACK; - ScaleFactor sf = ei.mi->scale_factor(pos, strongSide); + ScaleFactor sf = ei.me->scale_factor(pos, strongSide); // If we don't already have an unusual scale factor, check for certain // types of endgames, and use a lower scale for those. - if ( ei.mi->game_phase() < PHASE_MIDGAME + if ( ei.me->game_phase() < PHASE_MIDGAME && (sf == SCALE_FACTOR_NORMAL || sf == SCALE_FACTOR_ONEPAWN)) { if (pos.opposite_bishops()) @@ -767,138 +722,188 @@ namespace { // is almost a draw, in case of KBP vs KB is even more a draw. if ( pos.non_pawn_material(WHITE) == BishopValueMg && pos.non_pawn_material(BLACK) == BishopValueMg) - sf = more_than_one(pos.pieces(PAWN)) ? ScaleFactor(32) : ScaleFactor(8); + sf = more_than_one(pos.pieces(PAWN)) ? ScaleFactor(31) : ScaleFactor(9); // Endgame with opposite-colored bishops, but also other pieces. Still // a bit drawish, but not as drawish as with only the two bishops. else - sf = ScaleFactor(50 * sf / SCALE_FACTOR_NORMAL); + sf = ScaleFactor(46 * sf / SCALE_FACTOR_NORMAL); } // Endings where weaker side can place his king in front of the opponent's // pawns are drawish. else if ( abs(eg_value(score)) <= BishopValueEg && ei.pi->pawn_span(strongSide) <= 1 && !pos.pawn_passed(~strongSide, pos.square(~strongSide))) - sf = ei.pi->pawn_span(strongSide) ? ScaleFactor(56) : ScaleFactor(38); + sf = ei.pi->pawn_span(strongSide) ? ScaleFactor(51) : ScaleFactor(37); } - // Interpolate between a middlegame and a (scaled by 'sf') endgame score - Value v = mg_value(score) * int(ei.mi->game_phase()) - + eg_value(score) * int(PHASE_MIDGAME - ei.mi->game_phase()) * sf / SCALE_FACTOR_NORMAL; + return sf; + } + +} // namespace - v /= int(PHASE_MIDGAME); - // In case of tracing add all single evaluation terms for both white and black - if (Trace) - { - Tracing::write(Tracing::MATERIAL, pos.psq_score()); - Tracing::write(Tracing::IMBALANCE, ei.mi->imbalance()); - Tracing::write(PAWN, ei.pi->pawns_score()); - Tracing::write(Tracing::MOBILITY, mobility[WHITE] * Weights[Mobility] - , mobility[BLACK] * Weights[Mobility]); - Tracing::write(Tracing::SPACE, evaluate_space(pos, ei) * Weights[Space] - , evaluate_space(pos, ei) * Weights[Space]); - Tracing::write(Tracing::TOTAL, score); - } +/// evaluate() is the main evaluation function. It returns a static evaluation +/// of the position from the point of view of the side to move. - return (pos.side_to_move() == WHITE ? v : -v) + Eval::Tempo; // Side to move point of view - } +template +Value Eval::evaluate(const Position& pos) { + assert(!pos.checkers()); - // Tracing functions + EvalInfo ei; + Score score, mobility[2] = { SCORE_ZERO, SCORE_ZERO }; - double Tracing::to_cp(Value v) { return double(v) / PawnValueEg; } + // Initialize score by reading the incrementally updated scores included in + // the position object (material + piece square tables). Score is computed + // internally from the white point of view. + score = pos.psq_score(); - void Tracing::write(int idx, Color c, Score s) { scores[c][idx] = s; } + // Probe the material hash table + ei.me = Material::probe(pos); + score += ei.me->imbalance(); - void Tracing::write(int idx, Score w, Score b) { - scores[WHITE][idx] = w, scores[BLACK][idx] = b; - } + // If we have a specialized evaluation function for the current material + // configuration, call it and return. + if (ei.me->specialized_eval_exists()) + return ei.me->evaluate(pos); - std::ostream& Tracing::operator<<(std::ostream& os, Term t) { + // Probe the pawn hash table + ei.pi = Pawns::probe(pos); + score += ei.pi->pawns_score() * Weights[PawnStructure]; - double wScore[] = { to_cp(mg_value(scores[WHITE][t])), to_cp(eg_value(scores[WHITE][t])) }; - double bScore[] = { to_cp(mg_value(scores[BLACK][t])), to_cp(eg_value(scores[BLACK][t])) }; + // Initialize attack and king safety bitboards + ei.attackedBy[WHITE][ALL_PIECES] = ei.attackedBy[BLACK][ALL_PIECES] = 0; + eval_init(pos, ei); + eval_init(pos, ei); - if (t == MATERIAL || t == IMBALANCE || t == Term(PAWN) || t == TOTAL) - os << " --- --- | --- --- | "; - else - os << std::setw(5) << wScore[MG] << " " << std::setw(5) << wScore[EG] << " | " - << std::setw(5) << bScore[MG] << " " << std::setw(5) << bScore[EG] << " | "; + // Pawns blocked or on ranks 2 and 3 will be excluded from the mobility area + Bitboard blockedPawns[] = { + pos.pieces(WHITE, PAWN) & (shift_bb(pos.pieces()) | Rank2BB | Rank3BB), + pos.pieces(BLACK, PAWN) & (shift_bb(pos.pieces()) | Rank7BB | Rank6BB) + }; + + // Do not include in mobility area squares protected by enemy pawns, or occupied + // by our blocked pawns or king. + Bitboard mobilityArea[] = { + ~(ei.attackedBy[BLACK][PAWN] | blockedPawns[WHITE] | pos.square(WHITE)), + ~(ei.attackedBy[WHITE][PAWN] | blockedPawns[BLACK] | pos.square(BLACK)) + }; + + // Evaluate all pieces but king and pawns + score += evaluate_pieces(pos, ei, mobility, mobilityArea); + score += (mobility[WHITE] - mobility[BLACK]) * Weights[Mobility]; + + // Evaluate kings after all other pieces because we need full attack + // information when computing the king safety evaluation. + score += evaluate_king(pos, ei) + - evaluate_king(pos, ei); - os << std::setw(5) << wScore[MG] - bScore[MG] << " " - << std::setw(5) << wScore[EG] - bScore[EG] << " \n"; + // Evaluate tactical threats, we need full attack information including king + score += evaluate_threats(pos, ei) + - evaluate_threats(pos, ei); - return os; + // Evaluate passed pawns, we need full attack information including king + score += evaluate_passed_pawns(pos, ei) + - evaluate_passed_pawns(pos, ei); + + // If both sides have only pawns, score for potential unstoppable pawns + if (!pos.non_pawn_material(WHITE) && !pos.non_pawn_material(BLACK)) + { + Bitboard b; + if ((b = ei.pi->passed_pawns(WHITE)) != 0) + score += int(relative_rank(WHITE, frontmost_sq(WHITE, b))) * Unstoppable; + + if ((b = ei.pi->passed_pawns(BLACK)) != 0) + score -= int(relative_rank(BLACK, frontmost_sq(BLACK, b))) * Unstoppable; } - std::string Tracing::do_trace(const Position& pos) { - - std::memset(scores, 0, sizeof(scores)); - - Value v = do_evaluate(pos); - v = pos.side_to_move() == WHITE ? v : -v; // White's point of view - - std::stringstream ss; - ss << std::showpoint << std::noshowpos << std::fixed << std::setprecision(2) - << " Eval term | White | Black | Total \n" - << " | MG EG | MG EG | MG EG \n" - << "----------------+-------------+-------------+-------------\n" - << " Material | " << Term(MATERIAL) - << " Imbalance | " << Term(IMBALANCE) - << " Pawns | " << Term(PAWN) - << " Knights | " << Term(KNIGHT) - << " Bishop | " << Term(BISHOP) - << " Rooks | " << Term(ROOK) - << " Queens | " << Term(QUEEN) - << " Mobility | " << Term(MOBILITY) - << " King safety | " << Term(KING) - << " Threats | " << Term(THREAT) - << " Passed pawns | " << Term(PASSED) - << " Space | " << Term(SPACE) - << "----------------+-------------+-------------+-------------\n" - << " Total | " << Term(TOTAL); - - ss << "\nTotal Evaluation: " << to_cp(v) << " (white side)\n"; - - return ss.str(); + // Evaluate space for both sides, only during opening + if (pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) >= 12222) + score += ( evaluate_space(pos, ei) + - evaluate_space(pos, ei)) * Weights[Space]; + + // Evaluate position potential for the winning side + score += evaluate_initiative(pos, ei.pi->pawn_asymmetry(), eg_value(score)); + + // Evaluate scale factor for the winning side + ScaleFactor sf = evaluate_scale_factor(pos, ei, score); + + // Interpolate between a middlegame and a (scaled by 'sf') endgame score + Value v = mg_value(score) * int(ei.me->game_phase()) + + eg_value(score) * int(PHASE_MIDGAME - ei.me->game_phase()) * sf / SCALE_FACTOR_NORMAL; + + v /= int(PHASE_MIDGAME); + + // In case of tracing add all remaining individual evaluation terms + if (DoTrace) + { + Trace::add(MATERIAL, pos.psq_score()); + Trace::add(IMBALANCE, ei.me->imbalance()); + Trace::add(PAWN, ei.pi->pawns_score()); + Trace::add(MOBILITY, mobility[WHITE] * Weights[Mobility] + , mobility[BLACK] * Weights[Mobility]); + Trace::add(SPACE, evaluate_space(pos, ei) * Weights[Space] + , evaluate_space(pos, ei) * Weights[Space]); + Trace::add(TOTAL, score); } -} // namespace + return (pos.side_to_move() == WHITE ? v : -v) + Eval::Tempo; // Side to move point of view +} +// Explicit template instantiations +template Value Eval::evaluate(const Position&); +template Value Eval::evaluate(const Position&); -namespace Eval { - /// evaluate() is the main evaluation function. It returns a static evaluation - /// of the position always from the point of view of the side to move. +/// trace() is like evaluate(), but instead of returning a value, it returns +/// a string (suitable for outputting to stdout) that contains the detailed +/// descriptions and values of each evaluation term. Useful for debugging. - Value evaluate(const Position& pos) { - return do_evaluate(pos); - } +std::string Eval::trace(const Position& pos) { + std::memset(scores, 0, sizeof(scores)); - /// trace() is like evaluate(), but instead of returning a value, it returns - /// a string (suitable for outputting to stdout) that contains the detailed - /// descriptions and values of each evaluation term. It's mainly used for - /// debugging. - std::string trace(const Position& pos) { - return Tracing::do_trace(pos); - } + Value v = evaluate(pos); + v = pos.side_to_move() == WHITE ? v : -v; // White's point of view + std::stringstream ss; + ss << std::showpoint << std::noshowpos << std::fixed << std::setprecision(2) + << " Eval term | White | Black | Total \n" + << " | MG EG | MG EG | MG EG \n" + << "----------------+-------------+-------------+-------------\n" + << " Material | " << Term(MATERIAL) + << " Imbalance | " << Term(IMBALANCE) + << " Pawns | " << Term(PAWN) + << " Knights | " << Term(KNIGHT) + << " Bishop | " << Term(BISHOP) + << " Rooks | " << Term(ROOK) + << " Queens | " << Term(QUEEN) + << " Mobility | " << Term(MOBILITY) + << " King safety | " << Term(KING) + << " Threats | " << Term(THREAT) + << " Passed pawns | " << Term(PASSED) + << " Space | " << Term(SPACE) + << "----------------+-------------+-------------+-------------\n" + << " Total | " << Term(TOTAL); - /// init() computes evaluation weights, usually at startup + ss << "\nTotal Evaluation: " << to_cp(v) << " (white side)\n"; - void init() { + return ss.str(); +} - const int MaxSlope = 8700; - const int Peak = 1280000; - int t = 0; - for (int i = 0; i < 400; ++i) - { - t = std::min(Peak, std::min(i * i * 27, t + MaxSlope)); - KingDanger[i] = make_score(t / 1000, 0) * Weights[KingSafety]; - } - } +/// init() computes evaluation weights, usually at startup + +void Eval::init() { -} // namespace Eval + const int MaxSlope = 8700; + const int Peak = 1280000; + int t = 0; + + for (int i = 0; i < 400; ++i) + { + t = std::min(Peak, std::min(i * i * 27, t + MaxSlope)); + KingDanger[i] = make_score(t / 1000, 0) * Weights[KingSafety]; + } +}