X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fevaluate.cpp;h=5621c508f219d7ed7725c68f46b4a28032973fc4;hp=d8017065f0941b009e5d917da2f07d25a3a79ede;hb=de02768af7b37c903e3227b85ec4d81ec79ba69a;hpb=87886128288a82dabc78c2ce6dd688f42eaf8212 diff --git a/src/evaluate.cpp b/src/evaluate.cpp index d8017065..5621c508 100644 --- a/src/evaluate.cpp +++ b/src/evaluate.cpp @@ -2,7 +2,7 @@ Stockfish, a UCI chess playing engine derived from Glaurung 2.1 Copyright (C) 2004-2008 Tord Romstad (Glaurung author) Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad - Copyright (C) 2015-2016 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad + Copyright (C) 2015-2017 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad Stockfish is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -24,7 +24,7 @@ #include #include -#include "bitcount.h" +#include "bitboard.h" #include "evaluate.h" #include "material.h" #include "pawns.h" @@ -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), @@ -132,36 +137,40 @@ namespace { // 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(42,11), S(63,17) }, // Knights - { S(18, 5), S(27, 8) } // Bishops + { S(43,11), S(65,20) }, // Knights + { S(20, 3), S(29, 8) } // Bishops }; // 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 + { S(21, 5), S(35, 8) }, // Knights + { S( 8, 0), S(14, 4) } // Bishops }; // RookOnFile[semiopen/open] contains bonuses for each rook when there is no // friendly pawn on the rook file. - const Score RookOnFile[2] = { S(19, 10), S(43, 21) }; + const Score RookOnFile[2] = { S(20, 7), S(45, 20) }; // ThreatBySafePawn[PieceType] contains bonuses according to which piece // type is attacked by a pawn which is protected or is not attacked. const Score ThreatBySafePawn[PIECE_TYPE_NB] = { - S(0, 0), S(0, 0), S(176, 139), S(131, 127), S(217, 218), S(203, 215) }; - - // Threat[by minor/by rook][attacked PieceType] contains - // bonuses according to which piece type attacks which one. - // Attacks on lesser pieces which are pawn-defended are not considered. - const Score Threat[][PIECE_TYPE_NB] = { - { S(0, 0), S(0, 33), S(45, 43), S(46, 47), S(72,107), S(48,118) }, // by Minor - { S(0, 0), S(0, 25), S(40, 62), S(40, 59), S( 0, 34), S(35, 48) } // by Rook + S(0, 0), S(0, 0), S(176, 139), S(131, 127), S(217, 218), S(203, 215) + }; + + // ThreatByMinor/ByRook[attacked PieceType] contains bonuses according to + // which piece type attacks which one. Attacks on lesser pieces which are + // pawn-defended are not considered. + const Score ThreatByMinor[PIECE_TYPE_NB] = { + S(0, 0), S(0, 33), S(45, 43), S(46, 47), S(72, 107), S(48, 118) + }; + + const Score ThreatByRook[PIECE_TYPE_NB] = { + S(0, 0), S(0, 25), S(40, 62), S(40, 59), S( 0, 34), S(35, 48) }; - // ThreatByKing[on one/on many] contains bonuses for King attacks on + // ThreatByKing[on one/on many] contains bonuses for king attacks on // pawns or pieces which are not pawn-defended. const Score ThreatByKing[2] = { S(3, 62), S(9, 138) }; @@ -175,19 +184,24 @@ namespace { // PassedFile[File] contains a bonus according to the file of a passed pawn const Score PassedFile[FILE_NB] = { S( 9, 10), S( 2, 10), S( 1, -8), S(-20,-12), - S(-20,-12), S( 1, -8), S( 2, 10), S( 9, 10) + S(-20,-12), S( 1, -8), S( 2, 10), S( 9, 10) }; // Assorted bonuses and penalties used by evaluation const Score MinorBehindPawn = S(16, 0); const Score BishopPawns = S( 8, 12); - const Score RookOnPawn = S( 7, 27); + const Score RookOnPawn = S( 8, 24); const Score TrappedRook = S(92, 0); - const Score Checked = S(20, 20); - const Score ThreatByHangingPawn = S(70, 63); - const Score Hanging = S(48, 28); - const Score ThreatByPawnPush = S(31, 19); - const Score Unstoppable = S( 0, 20); + const Score WeakQueen = S(50, 10); + const Score OtherCheck = S(10, 10); + const Score CloseEnemies = S( 7, 0); + const Score PawnlessFlank = S(20, 80); + const Score LooseEnemies = S( 0, 25); + const Score ThreatByHangingPawn = S(71, 61); + const Score ThreatByRank = S(16, 3); + const Score Hanging = S(48, 27); + const Score ThreatByPawnPush = S(38, 22); + const Score HinderPassedPawn = S( 7, 0); // 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 @@ -197,22 +211,18 @@ namespace { #undef S #undef V - // 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 - // index to KingDanger[]. - Score KingDanger[512]; - // KingAttackWeights[PieceType] contains king attack weights by piece type - const int KingAttackWeights[PIECE_TYPE_NB] = { 0, 0, 7, 5, 4, 1 }; + const int KingAttackWeights[PIECE_TYPE_NB] = { 0, 0, 78, 56, 45, 11 }; // Penalties for enemy's safe checks - const int QueenContactCheck = 89; - const int QueenCheck = 50; - const int RookCheck = 45; - const int BishopCheck = 6; - const int KnightCheck = 14; + const int QueenContactCheck = 997; + const int QueenCheck = 745; + const int RookCheck = 688; + const int BishopCheck = 588; + const int KnightCheck = 924; + // Threshold for lazy evaluation + const Value LazyEval = Value(1500); // eval_init() initializes king and attack bitboards for a given color // adding pawn attacks. To be done at the beginning of the evaluation. @@ -220,20 +230,20 @@ namespace { template void eval_init(const Position& pos, EvalInfo& ei) { - const Color Them = (Us == WHITE ? BLACK : WHITE); - const Square Down = (Us == WHITE ? DELTA_S : DELTA_N); + const Color Them = (Us == WHITE ? BLACK : WHITE); + const Square Down = (Us == WHITE ? SOUTH : NORTH); 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.kingRing[Them] = b | shift(b); + ei.kingAttackersCount[Us] = popcount(b & ei.attackedBy[Us][PAWN]); ei.kingAdjacentZoneAttacksCount[Us] = ei.kingAttackersWeight[Us] = 0; } else @@ -247,16 +257,16 @@ namespace { 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); + Bitboard b, bb; + Square s; + Score score = SCORE_ZERO; + ei.attackedBy[Us][Pt] = 0; while ((s = *pl++) != SQ_NONE) @@ -269,15 +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) @@ -285,7 +294,7 @@ namespace { | ei.attackedBy[Them][BISHOP] | ei.attackedBy[Them][ROOK]); - int mob = popcount(b & mobilityArea[Us]); + int mob = popcount(b & mobilityArea[Us]); mobility[Us] += MobilityBonus[Pt][mob]; @@ -318,7 +327,7 @@ namespace { && pos.is_chess960() && (s == relative_square(Us, SQ_A1) || s == relative_square(Us, SQ_H1))) { - Square d = pawn_push(Us) + (file_of(s) == FILE_A ? DELTA_E : DELTA_W); + Square d = pawn_push(Us) + (file_of(s) == FILE_A ? EAST : WEST); if (pos.piece_on(s + d) == make_piece(Us, PAWN)) score -= !pos.empty(s + d + pawn_push(Us)) ? TrappedBishopA1H1 * 4 : pos.piece_on(s + d + d) == make_piece(Us, PAWN) ? TrappedBishopA1H1 * 2 @@ -330,11 +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))) @@ -346,11 +351,18 @@ namespace { Square ksq = pos.square(Us); if ( ((file_of(ksq) < FILE_E) == (file_of(s) < file_of(ksq))) - && (rank_of(ksq) == rank_of(s) || relative_rank(Us, ksq) == RANK_1) && !ei.pi->semiopen_side(Us, file_of(ksq), file_of(s) < file_of(ksq))) 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 + Bitboard pinners; + if (pos.slider_blockers(pos.pieces(Them, ROOK, BISHOP), s, pinners)) + score -= WeakQueen; + } } if (DoTrace) @@ -368,14 +380,24 @@ namespace { // evaluate_king() assigns bonuses and penalties to a king of a given color + const Bitboard CenterFiles = FileCBB | FileDBB | FileEBB | FileFBB; + + const Bitboard KingFlank[FILE_NB] = { + CenterFiles >> 2, CenterFiles >> 2, CenterFiles >> 2, CenterFiles, CenterFiles, + CenterFiles << 2, CenterFiles << 2, CenterFiles << 2 + }; + 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 ? NORTH : SOUTH); + const Bitboard Camp = (Us == WHITE ? ~Bitboard(0) ^ Rank6BB ^ Rank7BB ^ Rank8BB + : ~Bitboard(0) ^ Rank1BB ^ Rank2BB ^ Rank3BB); - Bitboard undefended, b, b1, b2, safe; - int attackUnits; const Square ksq = pos.square(Us); + Bitboard undefended, b, b1, b2, safe, other; + int kingDanger; // King shelter and enemy pawns storm Score score = ei.pi->king_safety(pos, ksq); @@ -383,67 +405,100 @@ namespace { // Main king safety evaluation if (ei.kingAttackersCount[Them]) { - // Find the attacked squares around the king which have no defenders - // apart from the king itself. - 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]); - - // Initialize the 'attackUnits' variable, which is used later on as an - // index into the KingDanger[] array. The initial value is based on the + // Find the attacked squares which are defended only by the king... + 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); + + // Initialize the 'kingDanger' variable, which will be transformed + // later into a king danger score. The initial value is based on the // 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(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; + kingDanger = std::min(807, ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) + + 101 * ei.kingAdjacentZoneAttacksCount[Them] + + 235 * popcount(undefended) + + 134 * (popcount(b) + !!ei.pinnedPieces[Us]) + - 717 * !pos.count(Them) + - 7 * mg_value(score) / 5 - 5; // 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 + kingDanger += QueenContactCheck * popcount(b & ei.attackedBy2[Them]); - // Analyse the enemy's safe distance checks for sliders and knights - safe = ~(ei.attackedBy[Us][ALL_PIECES] | pos.pieces(Them)); + // Analyse the safe enemy's checks which are possible on next move... + safe = ~(ei.attackedBy[Us][ALL_PIECES] | pos.pieces(Them)); - b1 = pos.attacks_from(ksq) & safe; - b2 = pos.attacks_from(ksq) & safe; + // ... 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(pos.pieces(PAWN)))); + + 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) + kingDanger += QueenCheck; + + // 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 checks - if (b1 & ei.attackedBy[Them][ROOK]) - attackUnits += RookCheck, score -= Checked; + // Enemy rooks safe and other checks + if (b1 & ei.attackedBy[Them][ROOK] & safe) + kingDanger += RookCheck; - // Enemy bishops safe checks - if (b2 & ei.attackedBy[Them][BISHOP]) - attackUnits += BishopCheck, score -= Checked; + else if (b1 & ei.attackedBy[Them][ROOK] & other) + score -= OtherCheck; - // Enemy knights safe checks - if (pos.attacks_from(ksq) & ei.attackedBy[Them][KNIGHT] & safe) - attackUnits += KnightCheck, score -= Checked; + // Enemy bishops safe and other checks + if (b2 & ei.attackedBy[Them][BISHOP] & safe) + kingDanger += BishopCheck; - // 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)]; + else if (b2 & ei.attackedBy[Them][BISHOP] & other) + score -= OtherCheck; + + // Enemy knights safe and other checks + b = pos.attacks_from(ksq) & ei.attackedBy[Them][KNIGHT]; + if (b & safe) + kingDanger += KnightCheck; + + else if (b & other) + score -= OtherCheck; + + // Compute the king danger score and subtract it from the evaluation + if (kingDanger > 0) + score -= make_score(std::min(kingDanger * kingDanger / 4096, 2 * int(BishopValueMg)), 0); } + // King tropism: firstly, find squares that opponent attacks in our king flank + File kf = file_of(ksq); + b = ei.attackedBy[Them][ALL_PIECES] & KingFlank[kf] & Camp; + + 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); + + // Penalty when our king is on a pawnless flank + if (!(pos.pieces(PAWN) & KingFlank[kf])) + score -= PawnlessFlank; + if (DoTrace) Trace::add(KING, Us, score); @@ -457,18 +512,21 @@ namespace { template Score evaluate_threats(const Position& pos, const EvalInfo& ei) { - const Color Them = (Us == WHITE ? BLACK : WHITE); - const Square Up = (Us == WHITE ? DELTA_N : DELTA_S); - const Square Left = (Us == WHITE ? DELTA_NW : DELTA_SE); - const Square Right = (Us == WHITE ? DELTA_NE : DELTA_SW); - const Bitboard TRank2BB = (Us == WHITE ? Rank2BB : Rank7BB); - const Bitboard TRank7BB = (Us == WHITE ? Rank7BB : Rank2BB); - - enum { Minor, Rook }; + const Color Them = (Us == WHITE ? BLACK : WHITE); + const Square Up = (Us == WHITE ? NORTH : SOUTH); + const Square Left = (Us == WHITE ? NORTH_WEST : SOUTH_EAST); + const Square Right = (Us == WHITE ? NORTH_EAST : SOUTH_WEST); + const Bitboard TRank2BB = (Us == WHITE ? Rank2BB : Rank7BB); + const Bitboard TRank7BB = (Us == WHITE ? Rank7BB : Rank2BB); Bitboard b, weak, defended, safeThreats; Score score = SCORE_ZERO; + // Small bonus if the opponent has loose pawns or pieces + if ( (pos.pieces(Them) ^ pos.pieces(Them, QUEEN, KING)) + & ~(ei.attackedBy[Us][ALL_PIECES] | ei.attackedBy[Them][ALL_PIECES])) + score += LooseEnemies; + // Non-pawn enemies attacked by a pawn weak = (pos.pieces(Them) ^ pos.pieces(Them, PAWN)) & ei.attackedBy[Us][PAWN]; @@ -477,7 +535,7 @@ namespace { b = pos.pieces(Us, PAWN) & ( ~ei.attackedBy[Them][ALL_PIECES] | ei.attackedBy[Us][ALL_PIECES]); - safeThreats = (shift_bb(b) | shift_bb(b)) & weak; + safeThreats = (shift(b) | shift(b)) & weak; if (weak ^ safeThreats) score += ThreatByHangingPawn; @@ -499,15 +557,23 @@ namespace { { b = (defended | weak) & (ei.attackedBy[Us][KNIGHT] | ei.attackedBy[Us][BISHOP]); while (b) - score += Threat[Minor][type_of(pos.piece_on(pop_lsb(&b)))]; + { + Square s = pop_lsb(&b); + score += ThreatByMinor[type_of(pos.piece_on(s))]; + if (type_of(pos.piece_on(s)) != PAWN) + score += ThreatByRank * (int)relative_rank(Them, s); + } b = (pos.pieces(Them, QUEEN) | weak) & ei.attackedBy[Us][ROOK]; while (b) - score += Threat[Rook ][type_of(pos.piece_on(pop_lsb(&b)))]; + { + Square s = pop_lsb(&b); + score += ThreatByRook[type_of(pos.piece_on(s))]; + if (type_of(pos.piece_on(s)) != PAWN) + score += ThreatByRank * (int)relative_rank(Them, s); + } - 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) @@ -516,18 +582,17 @@ namespace { // 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())); + b = shift(b | (shift(b & TRank2BB) & ~pos.pieces())); b &= ~pos.pieces() & ~ei.attackedBy[Them][PAWN] & (ei.attackedBy[Us][ALL_PIECES] | ~ei.attackedBy[Them][ALL_PIECES]); - b = (shift_bb(b) | shift_bb(b)) + b = (shift(b) | shift(b)) & pos.pieces(Them) & ~ei.attackedBy[Us][PAWN]; - if (b) - score += ThreatByPawnPush * popcount(b); + score += ThreatByPawnPush * popcount(b); if (DoTrace) Trace::add(THREAT, Us, score); @@ -543,7 +608,7 @@ namespace { const Color Them = (Us == WHITE ? BLACK : WHITE); - Bitboard b, squaresToQueen, defendedSquares, unsafeSquares; + Bitboard b, bb, squaresToQueen, defendedSquares, unsafeSquares; Score score = SCORE_ZERO; b = ei.pi->passed_pawns(Us); @@ -553,6 +618,10 @@ namespace { Square s = pop_lsb(&b); assert(pos.pawn_passed(Us, s)); + assert(!(pos.pieces(PAWN) & forward_bb(Us, s))); + + bb = forward_bb(Us, s) & (ei.attackedBy[Them][ALL_PIECES] | pos.pieces(Them)); + score -= HinderPassedPawn * popcount(bb); int r = relative_rank(Us, s) - RANK_2; int rr = r * (r - 1); @@ -579,7 +648,7 @@ namespace { // in the pawn's path attacked or occupied by the enemy. defendedSquares = unsafeSquares = squaresToQueen = forward_bb(Us, s); - Bitboard bb = forward_bb(Them, s) & pos.pieces(ROOK, QUEEN) & pos.attacks_from(s); + bb = forward_bb(Them, s) & pos.pieces(ROOK, QUEEN) & pos.attacks_from(s); if (!(pos.pieces(Us) & bb)) defendedSquares &= ei.attackedBy[Us][ALL_PIECES]; @@ -605,8 +674,9 @@ namespace { mbonus += rr + r * 2, ebonus += rr + r * 2; } // rr != 0 - if (pos.count(Us) < pos.count(Them)) - ebonus += ebonus / 4; + // Assign a small bonus when the opponent has no pieces left + if (!pos.non_pawn_material(Them)) + ebonus += 20; score += make_score(mbonus, ebonus) + PassedFile[file_of(s)]; } @@ -630,8 +700,8 @@ namespace { 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); + Us == WHITE ? CenterFiles & (Rank2BB | Rank3BB | Rank4BB) + : CenterFiles & (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 @@ -650,11 +720,11 @@ namespace { assert(unsigned(safe >> (Us == WHITE ? 32 : 0)) == 0); // ...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); + int bonus = popcount((Us == WHITE ? safe << 32 : safe >> 32) | (behind & safe)); + 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); } @@ -701,19 +771,31 @@ 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; } + + Value lazy_eval(Value mg, Value eg) { + + if (mg > LazyEval && eg > LazyEval) + return LazyEval + ((mg + eg) / 2 - LazyEval) / 4; + + else if (mg < -LazyEval && eg < -LazyEval) + return -LazyEval + ((mg + eg) / 2 + LazyEval) / 4; + + return VALUE_ZERO; + } + } // namespace @@ -725,36 +807,43 @@ Value Eval::evaluate(const Position& pos) { assert(!pos.checkers()); + Score mobility[COLOR_NB] = { SCORE_ZERO, SCORE_ZERO }; EvalInfo ei; - Score score, mobility[COLOR_NB] = { SCORE_ZERO, SCORE_ZERO }; - - // 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(); // Probe the material hash table ei.me = Material::probe(pos); - score += ei.me->imbalance(); // 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); + // Initialize score by reading the incrementally updated scores included in + // the position object (material + piece square tables) and the material + // imbalance. Score is computed internally from the white point of view. + Score score = pos.psq_score() + ei.me->imbalance(); + // Probe the pawn hash table ei.pi = Pawns::probe(pos); score += ei.pi->pawns_score(); + // We have taken into account all cheap evaluation terms. + // If score exceeds a threshold return a lazy evaluation. + Value lazy = lazy_eval(mg_value(score), eg_value(score)); + if (lazy) + return pos.side_to_move() == WHITE ? lazy : -lazy; + // 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); // 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) + pos.pieces(WHITE, PAWN) & (shift(pos.pieces()) | Rank2BB | Rank3BB), + pos.pieces(BLACK, PAWN) & (shift(pos.pieces()) | Rank7BB | Rank6BB) }; // Do not include in mobility area squares protected by enemy pawns, or occupied @@ -781,17 +870,6 @@ Value Eval::evaluate(const Position& pos) { 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 += Unstoppable * int(relative_rank(WHITE, frontmost_sq(WHITE, b))); - - if ((b = ei.pi->passed_pawns(BLACK)) != 0) - score -= Unstoppable * int(relative_rank(BLACK, frontmost_sq(BLACK, b))); - } - // 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) @@ -816,8 +894,9 @@ Value Eval::evaluate(const Position& pos) { Trace::add(IMBALANCE, ei.me->imbalance()); Trace::add(PAWN, ei.pi->pawns_score()); Trace::add(MOBILITY, mobility[WHITE], mobility[BLACK]); - Trace::add(SPACE, evaluate_space(pos, ei) - , evaluate_space(pos, ei)); + if (pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) >= 12222) + Trace::add(SPACE, evaluate_space(pos, ei) + , evaluate_space(pos, ei)); Trace::add(TOTAL, score); } @@ -864,19 +943,3 @@ std::string Eval::trace(const Position& pos) { return ss.str(); } - - -/// init() computes evaluation weights, usually at startup - -void Eval::init() { - - const int MaxSlope = 322; - const int Peak = 47410; - int t = 0; - - for (int i = 0; i < 400; ++i) - { - t = std::min(Peak, std::min(i * i - 16, t + MaxSlope)); - KingDanger[i] = make_score(t * 268 / 7700, 0); - } -}