X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fevaluate.cpp;h=35764b717207e38b3871f367d4edbe5c400f8fc6;hp=f245a430ec7e4097720566aea7187399e31fc045;hb=d909d10f33df023be46a2633608bdf655d1f5a62;hpb=1cbba8d6fadaae2c6e6df5c541c4e2b8a8bf5a0a diff --git a/src/evaluate.cpp b/src/evaluate.cpp index f245a430..35764b71 100644 --- a/src/evaluate.cpp +++ b/src/evaluate.cpp @@ -77,6 +77,11 @@ namespace { // attacked by a given color and piece type (can be also ALL_PIECES). Bitboard attackedBy[COLOR_NB][PIECE_TYPE_NB]; + // attackedBy2[color] are the squares attacked by 2 pieces of a given color, + // possibly via x-ray or by one pawn and one piece. Diagonal x-ray through + // pawn or squares attacked by 2 pawns are not explicitly added. + Bitboard attackedBy2[COLOR_NB]; + // kingRing[color] is the zone around the king which is considered // by the king safety evaluation. This consists of the squares directly // adjacent to the king, and the three (or two, for a king on an edge file) @@ -114,7 +119,7 @@ namespace { // game, indexed by piece type and number of attacked squares in the MobilityArea. const Score MobilityBonus[][32] = { {}, {}, - { S(-75,-76), S(-56,-54), S(- 9,-26), S( -2,-10), S( 6, 5), S( 15, 11), // Knights + { S(-75,-76), S(-56,-54), S( -9,-26), S( -2,-10), S( 6, 5), S( 15, 11), // Knights S( 22, 26), S( 30, 28), S( 36, 29) }, { S(-48,-58), S(-21,-19), S( 16, -2), S( 26, 12), S( 37, 22), S( 51, 42), // Bishops S( 54, 54), S( 63, 58), S( 65, 63), S( 71, 70), S( 79, 74), S( 81, 86), @@ -183,9 +188,12 @@ namespace { const Score BishopPawns = S( 8, 12); const Score RookOnPawn = S( 8, 24); const Score TrappedRook = S(92, 0); - const Score Checked = S(20, 20); + const Score CloseEnemies = S( 7, 0); + const Score SafeCheck = S(20, 20); + const Score OtherCheck = S(10, 10); const Score ThreatByHangingPawn = S(71, 61); const Score LooseEnemies = S( 0, 25); + const Score WeakQueen = S(35, 0); const Score Hanging = S(48, 27); const Score ThreatByPawnPush = S(38, 22); const Score Unstoppable = S( 0, 20); @@ -202,17 +210,17 @@ namespace { // in KingDanger[]. Various little "meta-bonuses" measuring the strength // of the enemy attack are added up into an integer, which is used as an // index to KingDanger[]. - Score KingDanger[512]; + Score KingDanger[400]; // KingAttackWeights[PieceType] contains king attack weights by piece type const int KingAttackWeights[PIECE_TYPE_NB] = { 0, 0, 7, 5, 4, 1 }; // Penalties for enemy's safe checks const int QueenContactCheck = 89; - const int QueenCheck = 52; - const int RookCheck = 45; - const int BishopCheck = 5; - const int KnightCheck = 17; + const int QueenCheck = 62; + const int RookCheck = 57; + const int BishopCheck = 48; + const int KnightCheck = 78; // eval_init() initializes king and attack bitboards for a given color @@ -225,16 +233,17 @@ namespace { const Square Down = (Us == WHITE ? DELTA_S : DELTA_N); ei.pinnedPieces[Us] = pos.pinned_pieces(Us); - Bitboard b = ei.attackedBy[Them][KING] = pos.attacks_from(pos.square(Them)); + Bitboard b = ei.attackedBy[Them][KING]; ei.attackedBy[Them][ALL_PIECES] |= b; ei.attackedBy[Us][ALL_PIECES] |= ei.attackedBy[Us][PAWN] = ei.pi->pawn_attacks(Us); + ei.attackedBy2[Us] = ei.attackedBy[Us][PAWN] & ei.attackedBy[Us][KING]; // Init king safety tables only if we are going to use them if (pos.non_pawn_material(Us) >= QueenValueMg) { ei.kingRing[Them] = b | shift_bb(b); b &= ei.attackedBy[Us][PAWN]; - ei.kingAttackersCount[Us] = b ? popcount(b) : 0; + ei.kingAttackersCount[Us] = popcount(b); ei.kingAdjacentZoneAttacksCount[Us] = ei.kingAttackersWeight[Us] = 0; } else @@ -270,15 +279,14 @@ namespace { if (ei.pinnedPieces[Us] & s) b &= LineBB[pos.square(Us)][s]; + ei.attackedBy2[Us] |= ei.attackedBy[Us][ALL_PIECES] & b; ei.attackedBy[Us][ALL_PIECES] |= ei.attackedBy[Us][Pt] |= b; if (b & ei.kingRing[Them]) { ei.kingAttackersCount[Us]++; ei.kingAttackersWeight[Us] += KingAttackWeights[Pt]; - bb = b & ei.attackedBy[Them][KING]; - if (bb) - ei.kingAdjacentZoneAttacksCount[Us] += popcount(bb); + ei.kingAdjacentZoneAttacksCount[Us] += popcount(b & ei.attackedBy[Them][KING]); } if (Pt == QUEEN) @@ -331,11 +339,7 @@ namespace { { // Bonus for aligning with enemy pawns on the same rank/file if (relative_rank(Us, s) >= RANK_5) - { - Bitboard alignedPawns = pos.pieces(Them, PAWN) & PseudoAttacks[ROOK][s]; - if (alignedPawns) - score += RookOnPawn * popcount(alignedPawns); - } + score += RookOnPawn * popcount(pos.pieces(Them, PAWN) & PseudoAttacks[ROOK][s]); // Bonus when on an open or semi-open file if (ei.pi->semiopen_file(Us, file_of(s))) @@ -352,6 +356,13 @@ namespace { score -= (TrappedRook - make_score(mob * 22, 0)) * (1 + !pos.can_castle(Us)); } } + + if (Pt == QUEEN) + { + // Penalty if any relative pin or discovered attack against the queen + if (pos.slider_blockers(pos.pieces(Them, ROOK, BISHOP), s)) + score -= WeakQueen; + } } if (DoTrace) @@ -369,12 +380,26 @@ namespace { // evaluate_king() assigns bonuses and penalties to a king of a given color + const Bitboard WhiteCamp = Rank1BB | Rank2BB | Rank3BB | Rank4BB | Rank5BB; + const Bitboard BlackCamp = Rank8BB | Rank7BB | Rank6BB | Rank5BB | Rank4BB; + const Bitboard QueenSide = FileABB | FileBBB | FileCBB | FileDBB; + const Bitboard CenterFiles = FileCBB | FileDBB | FileEBB | FileFBB; + const Bitboard KingSide = FileEBB | FileFBB | FileGBB | FileHBB; + + const Bitboard KingFlank[COLOR_NB][FILE_NB] = { + { QueenSide & WhiteCamp, QueenSide & WhiteCamp, QueenSide & WhiteCamp, CenterFiles & WhiteCamp, + CenterFiles & WhiteCamp, KingSide & WhiteCamp, KingSide & WhiteCamp, KingSide & WhiteCamp }, + { QueenSide & BlackCamp, QueenSide & BlackCamp, QueenSide & BlackCamp, CenterFiles & BlackCamp, + CenterFiles & BlackCamp, KingSide & BlackCamp, KingSide & BlackCamp, KingSide & BlackCamp }, + }; + template Score evaluate_king(const Position& pos, const EvalInfo& ei) { - const Color Them = (Us == WHITE ? BLACK : WHITE); + const Color Them = (Us == WHITE ? BLACK : WHITE); + const Square Up = (Us == WHITE ? DELTA_N : DELTA_S); - Bitboard undefended, b, b1, b2, safe; + Bitboard undefended, b, b1, b2, safe, other; int attackUnits; const Square ksq = pos.square(Us); @@ -385,15 +410,13 @@ namespace { if (ei.kingAttackersCount[Them]) { // Find the attacked squares which are defended only by the king... - undefended = ei.attackedBy[Them][ALL_PIECES] - & ei.attackedBy[Us][KING] - & ~( ei.attackedBy[Us][PAWN] | ei.attackedBy[Us][KNIGHT] - | ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK] - | ei.attackedBy[Us][QUEEN]); + undefended = ei.attackedBy[Them][ALL_PIECES] + & ei.attackedBy[Us][KING] + & ~ei.attackedBy2[Us]; // ... and those which are not defended at all in the larger king ring - b = ei.attackedBy[Them][ALL_PIECES] & ~ei.attackedBy[Us][ALL_PIECES] - & ei.kingRing[Us] & ~pos.pieces(Them); + b = ei.attackedBy[Them][ALL_PIECES] & ~ei.attackedBy[Us][ALL_PIECES] + & ei.kingRing[Us] & ~pos.pieces(Them); // Initialize the 'attackUnits' variable, which is used later on as an // index into the KingDanger[] array. The initial value is based on the @@ -402,52 +425,79 @@ namespace { // the pawn shelter (current 'score' value). attackUnits = std::min(72, ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) + 9 * ei.kingAdjacentZoneAttacksCount[Them] - + 27 * popcount(undefended) - + 11 * (popcount(b) + !!ei.pinnedPieces[Us]) + + 21 * popcount(undefended) + + 12 * (popcount(b) + !!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... b = undefended & ei.attackedBy[Them][QUEEN] & ~pos.pieces(Them); - 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] | ei.attackedBy[Them][ROOK] - | ei.attackedBy[Them][KING]; - if (b) - attackUnits += QueenContactCheck * popcount(b); - } + // ...and keep squares supported by another enemy piece + attackUnits += QueenContactCheck * popcount(b & ei.attackedBy2[Them]); + + // Analyse the safe enemy's checks which are possible on next move... + safe = ~(ei.attackedBy[Us][ALL_PIECES] | pos.pieces(Them)); - // Analyse the enemy's safe distance checks for sliders and knights - safe = ~(ei.attackedBy[Us][ALL_PIECES] | pos.pieces(Them)); + // ... and some other potential checks, only requiring the square to be + // safe from pawn-attacks, and not being occupied by a blocked pawn. + other = ~( ei.attackedBy[Us][PAWN] + | (pos.pieces(Them, PAWN) & shift_bb(pos.pieces(PAWN)))); - b1 = pos.attacks_from(ksq) & safe; - b2 = pos.attacks_from(ksq) & safe; + b1 = pos.attacks_from(ksq); + b2 = pos.attacks_from(ksq); // Enemy queen safe checks - if ((b1 | b2) & ei.attackedBy[Them][QUEEN]) - attackUnits += QueenCheck, score -= Checked; + if ((b1 | b2) & ei.attackedBy[Them][QUEEN] & safe) + attackUnits += QueenCheck, score -= SafeCheck; + + // For other pieces, also consider the square safe if attacked twice, + // and only defended by a queen. + safe |= ei.attackedBy2[Them] + & ~(ei.attackedBy2[Us] | pos.pieces(Them)) + & ei.attackedBy[Us][QUEEN]; + + // Enemy rooks safe and other checks + if (b1 & ei.attackedBy[Them][ROOK] & safe) + attackUnits += RookCheck, score -= SafeCheck; + + else if (b1 & ei.attackedBy[Them][ROOK] & other) + score -= OtherCheck; + + // Enemy bishops safe and other checks + if (b2 & ei.attackedBy[Them][BISHOP] & safe) + attackUnits += BishopCheck, score -= SafeCheck; - // Enemy rooks safe checks - if (b1 & ei.attackedBy[Them][ROOK]) - attackUnits += RookCheck, score -= Checked; + else if (b2 & ei.attackedBy[Them][BISHOP] & other) + score -= OtherCheck; - // Enemy bishops safe checks - if (b2 & ei.attackedBy[Them][BISHOP]) - attackUnits += BishopCheck, score -= Checked; + // Enemy knights safe and other checks + b = pos.attacks_from(ksq) & ei.attackedBy[Them][KNIGHT]; + if (b & safe) + attackUnits += KnightCheck, score -= SafeCheck; - // Enemy knights safe checks - if (pos.attacks_from(ksq) & ei.attackedBy[Them][KNIGHT] & safe) - attackUnits += KnightCheck, score -= Checked; + else if (b & other) + score -= OtherCheck; // Finally, extract the king danger score from the KingDanger[] // array and subtract the score from the evaluation. score -= KingDanger[std::max(std::min(attackUnits, 399), 0)]; } + // King tropism: firstly, find squares that opponent attacks in our king flank + b = ei.attackedBy[Them][ALL_PIECES] & KingFlank[Us][file_of(ksq)]; + + assert(((Us == WHITE ? b << 4 : b >> 4) & b) == 0); + assert(popcount(Us == WHITE ? b << 4 : b >> 4) == popcount(b)); + + // Secondly, add the squares which are attacked twice in that flank and + // which are not defended by our pawns. + b = (Us == WHITE ? b << 4 : b >> 4) + | (b & ei.attackedBy2[Them] & ~ei.attackedBy[Us][PAWN]); + + score -= CloseEnemies * popcount(b); + if (DoTrace) Trace::add(KING, Us, score); @@ -514,9 +564,7 @@ namespace { while (b) score += Threat[Rook ][type_of(pos.piece_on(pop_lsb(&b)))]; - b = weak & ~ei.attackedBy[Them][ALL_PIECES]; - if (b) - score += Hanging * popcount(b); + score += Hanging * popcount(weak & ~ei.attackedBy[Them][ALL_PIECES]); b = weak & ei.attackedBy[Us][KING]; if (b) @@ -535,8 +583,7 @@ namespace { & pos.pieces(Them) & ~ei.attackedBy[Us][PAWN]; - if (b) - score += ThreatByPawnPush * popcount(b); + score += ThreatByPawnPush * popcount(b); if (DoTrace) Trace::add(THREAT, Us, score); @@ -562,6 +609,7 @@ namespace { Square s = pop_lsb(&b); assert(pos.pawn_passed(Us, s)); + assert(!(pos.pieces(PAWN) & forward_bb(Us, s))); int r = relative_rank(Us, s) - RANK_2; int rr = r * (r - 1); @@ -657,10 +705,10 @@ namespace { // ...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); + bonus = std::min(16, bonus); + int weight = pos.count(Us) - 2 * ei.pi->open_files(); - return make_score(bonus * weight * weight * 2 / 11, 0); + return make_score(bonus * weight * weight / 18, 0); } @@ -707,14 +755,14 @@ namespace { // 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(46 * sf / SCALE_FACTOR_NORMAL); + sf = ScaleFactor(46); } // Endings where weaker side can place his king in front of the opponent's // pawns are drawish. else if ( abs(eg) <= BishopValueEg - && ei.pi->pawn_span(strongSide) <= 1 + && pos.count(strongSide) <= 2 && !pos.pawn_passed(~strongSide, pos.square(~strongSide))) - sf = ei.pi->pawn_span(strongSide) ? ScaleFactor(51) : ScaleFactor(37); + sf = ScaleFactor(37 + 7 * pos.count(strongSide)); } return sf; @@ -754,6 +802,8 @@ Value Eval::evaluate(const Position& pos) { // Initialize attack and king safety bitboards ei.attackedBy[WHITE][ALL_PIECES] = ei.attackedBy[BLACK][ALL_PIECES] = 0; + ei.attackedBy[WHITE][KING] = pos.attacks_from(pos.square(WHITE)); + ei.attackedBy[BLACK][KING] = pos.attacks_from(pos.square(BLACK)); eval_init(pos, ei); eval_init(pos, ei);