X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fevaluate.cpp;h=a3f42dbef7ab4ef8c48b7a0afbc2fcd132dc8194;hp=af7a9d34edde97fc2911433ef1f57ca5eee815df;hb=cf893bcded1ae2d0cdf95caa7a41a020fe450cbd;hpb=e3a8b8bcff893d078e219637b3d0dcaeaa04beb2 diff --git a/src/evaluate.cpp b/src/evaluate.cpp index af7a9d34..a3f42dbe 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 @@ -73,6 +73,10 @@ namespace { // by the evaluation functions. struct EvalInfo { + Material::Entry* me; + Pawns::Entry* pe; + Bitboard mobilityArea[COLOR_NB]; + // attackedBy[color][piece type] is a bitboard representing all squares // attacked by a given color and piece type (can be also ALL_PIECES). Bitboard attackedBy[COLOR_NB][PIECE_TYPE_NB]; @@ -84,7 +88,7 @@ namespace { // 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) + // adjacent to the king, and (only for a king on its first rank) the // squares two ranks in front of the king. For instance, if black's king // is on g8, kingRing[BLACK] is a bitboard containing the squares f8, h8, // f7, g7, h7, f6, g6 and h6. @@ -106,58 +110,41 @@ namespace { // a white knight on g5 and black's king is on g8, this white knight adds 2 // to kingAdjacentZoneAttacksCount[WHITE]. int kingAdjacentZoneAttacksCount[COLOR_NB]; - - Bitboard pinnedPieces[COLOR_NB]; - Material::Entry* me; - Pawns::Entry* pi; }; #define V(v) Value(v) #define S(mg, eg) make_score(mg, eg) - // MobilityBonus[PieceType][attacked] contains bonuses for middle and end - // game, indexed by piece type and number of attacked squares in the MobilityArea. + // MobilityBonus[PieceType-2][attacked] contains bonuses for middle and end game, + // indexed by piece type and number of attacked squares in the mobility area. const Score MobilityBonus[][32] = { - {}, {}, - { 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), - S( 92, 90), S( 97, 94) }, - { S(-56,-78), S(-25,-18), S(-11, 26), S( -5, 55), S( -4, 70), S( -1, 81), // Rooks - S( 8,109), S( 14,120), S( 21,128), S( 23,143), S( 31,154), S( 32,160), - S( 43,165), S( 49,168), S( 59,169) }, - { S(-40,-35), S(-25,-12), S( 2, 7), S( 4, 19), S( 14, 37), S( 24, 55), // Queens - S( 25, 62), S( 40, 76), S( 43, 79), S( 47, 87), S( 54, 94), S( 56,102), - S( 60,111), S( 70,116), S( 72,118), S( 73,122), S( 75,128), S( 77,130), - S( 85,133), S( 94,136), S( 99,140), S(108,157), S(112,158), S(113,161), - S(118,174), S(119,177), S(123,191), S(128,199) } + { S(-75,-76), S(-57,-54), S( -9,-28), S( -2,-10), S( 6, 5), S( 14, 12), // Knights + S( 22, 26), S( 29, 29), S( 36, 29) }, + { S(-48,-59), S(-20,-23), S( 16, -3), S( 26, 13), S( 38, 24), S( 51, 42), // Bishops + 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), // Rooks + 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), // Queens + 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) } }; - // Outpost[knight/bishop][supported by pawn] contains bonuses for knights and - // bishops outposts, bigger if outpost piece is supported by a pawn. + // Outpost[knight/bishop][supported by pawn] contains bonuses for minor + // pieces if they can reach an outpost square, bigger if that square is + // supported by a pawn. If the minor piece occupies an outpost square + // then score is doubled. const Score Outpost[][2] = { - { 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(35, 8) }, // Knights - { S( 8, 0), S(14, 4) } // Bishops + { S(22, 6), S(33, 9) }, // Knight + { S( 9, 2), S(14, 4) } // Bishop }; // RookOnFile[semiopen/open] contains bonuses for each rook when there is no // friendly pawn on the rook file. - 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) - }; + const Score RookOnFile[] = { S(20, 7), S(45, 20) }; // ThreatByMinor/ByRook[attacked PieceType] contains bonuses according to // which piece type attacks which one. Attacks on lesser pieces which are @@ -172,7 +159,7 @@ namespace { // 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) }; + const Score ThreatByKing[] = { S(3, 62), S(9, 138) }; // 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. @@ -187,21 +174,24 @@ namespace { S(-20,-12), S( 1, -8), S( 2, 10), S( 9, 10) }; + // KingProtector[PieceType-2] contains a bonus according to distance from king + const Score KingProtector[] = { S(-3, -5), S(-4, -3), S(-3, 0), S(-1, 1) }; + // Assorted bonuses and penalties used by evaluation - const Score MinorBehindPawn = S(16, 0); - const Score BishopPawns = S( 8, 12); - const Score RookOnPawn = S( 8, 24); - const Score TrappedRook = S(92, 0); - 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); + const Score MinorBehindPawn = S( 16, 0); + const Score BishopPawns = S( 8, 12); + const Score RookOnPawn = S( 8, 24); + const Score TrappedRook = S( 92, 0); + 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 ThreatByHangingPawn = S( 71, 61); + const Score ThreatBySafePawn = S(182,175); + 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 @@ -215,12 +205,14 @@ namespace { const int KingAttackWeights[PIECE_TYPE_NB] = { 0, 0, 78, 56, 45, 11 }; // Penalties for enemy's safe checks - const int QueenContactCheck = 997; - const int QueenCheck = 745; - const int RookCheck = 688; - const int BishopCheck = 588; - const int KnightCheck = 924; + const int QueenCheck = 780; + const int RookCheck = 880; + const int BishopCheck = 435; + const int KnightCheck = 790; + // Threshold for lazy and space evaluation + const Value LazyThreshold = Value(1500); + const Value SpaceThreshold = Value(12222); // eval_init() initializes king and attack bitboards for a given color // adding pawn attacks. To be done at the beginning of the evaluation. @@ -229,23 +221,36 @@ namespace { void eval_init(const Position& pos, EvalInfo& ei) { const Color Them = (Us == WHITE ? BLACK : WHITE); + const Square Up = (Us == WHITE ? NORTH : SOUTH); const Square Down = (Us == WHITE ? SOUTH : NORTH); + const Bitboard LowRanks = (Us == WHITE ? Rank2BB | Rank3BB: Rank7BB | Rank6BB); - ei.pinnedPieces[Us] = pos.pinned_pieces(Us); - 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]; + // Find our pawns on the first two ranks, and those which are blocked + Bitboard b = pos.pieces(Us, PAWN) & (shift(pos.pieces()) | LowRanks); - // Init king safety tables only if we are going to use them - if (pos.non_pawn_material(Us) >= QueenValueMg) + // Squares occupied by those pawns, by our king, or controlled by enemy pawns + // are excluded from the mobility area. + ei.mobilityArea[Us] = ~(b | pos.square(Us) | ei.pe->pawn_attacks(Them)); + + // Initialise the attack bitboards with the king and pawn information + b = ei.attackedBy[Us][KING] = pos.attacks_from(pos.square(Us)); + ei.attackedBy[Us][PAWN] = ei.pe->pawn_attacks(Us); + + ei.attackedBy2[Us] = b & ei.attackedBy[Us][PAWN]; + ei.attackedBy[Us][ALL_PIECES] = b | ei.attackedBy[Us][PAWN]; + + // Init our king safety tables only if we are going to use them + if (pos.non_pawn_material(Them) >= QueenValueMg) { - ei.kingRing[Them] = b | shift(b); - ei.kingAttackersCount[Us] = popcount(b & ei.attackedBy[Us][PAWN]); - ei.kingAdjacentZoneAttacksCount[Us] = ei.kingAttackersWeight[Us] = 0; + ei.kingRing[Us] = b; + if (relative_rank(Us, pos.square(Us)) == RANK_1) + ei.kingRing[Us] |= shift(b); + + ei.kingAttackersCount[Them] = popcount(b & ei.pe->pawn_attacks(Them)); + ei.kingAdjacentZoneAttacksCount[Them] = ei.kingAttackersWeight[Them] = 0; } else - ei.kingRing[Them] = ei.kingAttackersCount[Us] = 0; + ei.kingRing[Us] = ei.kingAttackersCount[Them] = 0; } @@ -253,10 +258,10 @@ namespace { // color and type. template - Score evaluate_pieces(const Position& pos, EvalInfo& ei, Score* mobility, - const Bitboard* mobilityArea) { - const PieceType NextPt = (Us == WHITE ? Pt : PieceType(Pt + 1)); + Score evaluate_pieces(const Position& pos, EvalInfo& ei, Score* mobility) { + const Color Them = (Us == WHITE ? BLACK : WHITE); + const PieceType NextPt = (Us == WHITE ? Pt : PieceType(Pt + 1)); const Bitboard OutpostRanks = (Us == WHITE ? Rank4BB | Rank5BB | Rank6BB : Rank5BB | Rank4BB | Rank3BB); const Square* pl = pos.squares(Us); @@ -274,7 +279,7 @@ namespace { : Pt == ROOK ? attacks_bb< ROOK>(s, pos.pieces() ^ pos.pieces(Us, ROOK, QUEEN)) : pos.attacks_from(s); - if (ei.pinnedPieces[Us] & s) + if (pos.pinned_pieces(Us) & s) b &= LineBB[pos.square(Us)][s]; ei.attackedBy2[Us] |= ei.attackedBy[Us][ALL_PIECES] & b; @@ -287,26 +292,24 @@ namespace { ei.kingAdjacentZoneAttacksCount[Us] += popcount(b & ei.attackedBy[Them][KING]); } - if (Pt == QUEEN) - b &= ~( ei.attackedBy[Them][KNIGHT] - | ei.attackedBy[Them][BISHOP] - | ei.attackedBy[Them][ROOK]); + int mob = popcount(b & ei.mobilityArea[Us]); - int mob = popcount(b & mobilityArea[Us]); + mobility[Us] += MobilityBonus[Pt - 2][mob]; - mobility[Us] += MobilityBonus[Pt][mob]; + // Bonus for this piece as a king protector + score += KingProtector[Pt - 2] * distance(s, pos.square(Us)); if (Pt == BISHOP || Pt == KNIGHT) { // Bonus for outpost squares - bb = OutpostRanks & ~ei.pi->pawn_attacks_span(Them); + bb = OutpostRanks & ~ei.pe->pawn_attacks_span(Them); if (bb & s) - score += Outpost[Pt == BISHOP][!!(ei.attackedBy[Us][PAWN] & s)]; + score += Outpost[Pt == BISHOP][!!(ei.attackedBy[Us][PAWN] & s)] * 2; else { bb &= b & ~pos.pieces(Us); if (bb) - score += ReachableOutpost[Pt == BISHOP][!!(ei.attackedBy[Us][PAWN] & bb)]; + score += Outpost[Pt == BISHOP][!!(ei.attackedBy[Us][PAWN] & bb)]; } // Bonus when behind a pawn @@ -316,7 +319,7 @@ namespace { // Penalty for pawns on the same color square as the bishop if (Pt == BISHOP) - score -= BishopPawns * ei.pi->pawns_on_same_color_squares(Us, s); + score -= BishopPawns * ei.pe->pawns_on_same_color_squares(Us, s); // An important Chess960 pattern: A cornered bishop blocked by a friendly // pawn diagonally in front of it is a very serious problem, especially @@ -340,16 +343,16 @@ namespace { 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))) - score += RookOnFile[!!ei.pi->semiopen_file(Them, file_of(s))]; + if (ei.pe->semiopen_file(Us, file_of(s))) + score += RookOnFile[!!ei.pe->semiopen_file(Them, file_of(s))]; - // Penalize when trapped by the king, even more if the king cannot castle + // Penalty when trapped by the king, even more if the king cannot castle else if (mob <= 3) { Square ksq = pos.square(Us); if ( ((file_of(ksq) < FILE_E) == (file_of(s) < file_of(ksq))) - && !ei.pi->semiopen_side(Us, file_of(ksq), file_of(s) < file_of(ksq))) + && !ei.pe->semiopen_side(Us, file_of(ksq), file_of(s) < file_of(ksq))) score -= (TrappedRook - make_score(mob * 22, 0)) * (1 + !pos.can_castle(Us)); } } @@ -367,22 +370,23 @@ namespace { Trace::add(Pt, Us, score); // Recursively call evaluate_pieces() of next piece type until KING is excluded - return score - evaluate_pieces(pos, ei, mobility, mobilityArea); + return score - evaluate_pieces(pos, ei, mobility); } template<> - Score evaluate_pieces(const Position&, EvalInfo&, Score*, const Bitboard*) { return SCORE_ZERO; } + Score evaluate_pieces(const Position&, EvalInfo&, Score*) { return SCORE_ZERO; } template<> - Score evaluate_pieces< true, WHITE, KING>(const Position&, EvalInfo&, Score*, const Bitboard*) { return SCORE_ZERO; } + Score evaluate_pieces< true, WHITE, KING>(const Position&, EvalInfo&, Score*) { return SCORE_ZERO; } // evaluate_king() assigns bonuses and penalties to a king of a given color + const Bitboard QueenSide = FileABB | FileBBB | FileCBB | FileDBB; const Bitboard CenterFiles = FileCBB | FileDBB | FileEBB | FileFBB; + const Bitboard KingSide = FileEBB | FileFBB | FileGBB | FileHBB; const Bitboard KingFlank[FILE_NB] = { - CenterFiles >> 2, CenterFiles >> 2, CenterFiles >> 2, CenterFiles, CenterFiles, - CenterFiles << 2, CenterFiles << 2, CenterFiles << 2 + QueenSide, QueenSide, QueenSide, CenterFiles, CenterFiles, KingSide, KingSide, KingSide }; template @@ -398,12 +402,12 @@ namespace { int kingDanger; // King shelter and enemy pawns storm - Score score = ei.pi->king_safety(pos, ksq); + Score score = ei.pe->king_safety(pos, ksq); // Main king safety evaluation if (ei.kingAttackersCount[Them]) { - // Find the attacked squares which are defended only by the king... + // Find the attacked squares which are defended only by our king... undefended = ei.attackedBy[Them][ALL_PIECES] & ei.attackedBy[Us][KING] & ~ei.attackedBy2[Us]; @@ -417,27 +421,16 @@ 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). - 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); + kingDanger = ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them] + + 102 * ei.kingAdjacentZoneAttacksCount[Them] + + 201 * popcount(undefended) + + 143 * (popcount(b) + !!pos.pinned_pieces(Us)) + - 848 * !pos.count(Them) + - 28 * mg_value(score) / 25 - 5; - // ...and keep squares supported by another enemy piece - kingDanger += 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)); - - // ... 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)))); + // Analyse the safe enemy's checks which are possible on next move + safe = ~pos.pieces(Them); + safe &= ~ei.attackedBy[Us][ALL_PIECES] | (undefended & ei.attackedBy2[Them]); b1 = pos.attacks_from(ksq); b2 = pos.attacks_from(ksq); @@ -446,12 +439,18 @@ namespace { 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. + // For minors and rooks, also consider the square safe if attacked twice, + // and only defended by our queen. safe |= ei.attackedBy2[Them] & ~(ei.attackedBy2[Us] | pos.pieces(Them)) & ei.attackedBy[Us][QUEEN]; + // Some other potential checks are also analysed, even from squares + // currently occupied by the opponent own pieces, as long as the square + // is not attacked by our pawns, and is not occupied by a blocked pawn. + other = ~( ei.attackedBy[Us][PAWN] + | (pos.pieces(Them, PAWN) & shift(pos.pieces(PAWN)))); + // Enemy rooks safe and other checks if (b1 & ei.attackedBy[Them][ROOK] & safe) kingDanger += RookCheck; @@ -474,9 +473,9 @@ namespace { else if (b & other) score -= OtherCheck; - // Compute the king danger score and subtract it from the evaluation + // Transform the kingDanger units into a Score, and substract it from the evaluation if (kingDanger > 0) - score -= make_score(std::min(kingDanger * kingDanger / 4096, 2 * int(BishopValueMg)), 0); + score -= make_score(kingDanger * kingDanger / 4096, kingDanger / 16); } // King tropism: firstly, find squares that opponent attacks in our king flank @@ -517,14 +516,9 @@ namespace { const Bitboard TRank2BB = (Us == WHITE ? Rank2BB : Rank7BB); const Bitboard TRank7BB = (Us == WHITE ? Rank7BB : Rank2BB); - Bitboard b, weak, defended, safeThreats; + Bitboard b, weak, defended, stronglyProtected, 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]; @@ -535,19 +529,24 @@ namespace { safeThreats = (shift(b) | shift(b)) & weak; + score += ThreatBySafePawn * popcount(safeThreats); + if (weak ^ safeThreats) score += ThreatByHangingPawn; - - while (safeThreats) - score += ThreatBySafePawn[type_of(pos.piece_on(pop_lsb(&safeThreats)))]; } - // Non-pawn enemies defended by a pawn - defended = (pos.pieces(Them) ^ pos.pieces(Them, PAWN)) & ei.attackedBy[Them][PAWN]; + // Squares strongly protected by the opponent, either because they attack the + // square with a pawn, or because they attack the square twice and we don't. + stronglyProtected = ei.attackedBy[Them][PAWN] + | (ei.attackedBy2[Them] & ~ei.attackedBy2[Us]); + + // Non-pawn enemies, strongly protected + defended = (pos.pieces(Them) ^ pos.pieces(Them, PAWN)) + & stronglyProtected; - // Enemies not defended by a pawn and under our attack + // Enemies not strongly protected and under our attack weak = pos.pieces(Them) - & ~ei.attackedBy[Them][PAWN] + & ~stronglyProtected & ei.attackedBy[Us][ALL_PIECES]; // Add a bonus according to the kind of attacking pieces @@ -599,24 +598,24 @@ namespace { } - // evaluate_passed_pawns() evaluates the passed pawns of the given color + // evaluate_passer_pawns() evaluates the passed pawns and candidate passed + // pawns of the given color. template - Score evaluate_passed_pawns(const Position& pos, const EvalInfo& ei) { + Score evaluate_passer_pawns(const Position& pos, const EvalInfo& ei) { const Color Them = (Us == WHITE ? BLACK : WHITE); Bitboard b, bb, squaresToQueen, defendedSquares, unsafeSquares; Score score = SCORE_ZERO; - b = ei.pi->passed_pawns(Us); + b = ei.pe->passed_pawns(Us); while (b) { Square s = pop_lsb(&b); - assert(pos.pawn_passed(Us, s)); - assert(!(pos.pieces(PAWN) & forward_bb(Us, s))); + assert(!(pos.pieces(Them, PAWN) & forward_bb(Us, s + pawn_push(Us)))); bb = forward_bb(Us, s) & (ei.attackedBy[Them][ALL_PIECES] | pos.pieces(Them)); score -= HinderPassedPawn * popcount(bb); @@ -672,9 +671,10 @@ namespace { mbonus += rr + r * 2, ebonus += rr + r * 2; } // rr != 0 - // Assign a small bonus when the opponent has no pieces left - if (!pos.non_pawn_material(Them)) - ebonus += 20; + // Scale down bonus for candidate passers which need more than one + // pawn push to become passed or have a pawn in front of them. + if (!pos.pawn_passed(Us, s + pawn_push(Us)) || (pos.pieces(PAWN) & forward_bb(Us, s))) + mbonus /= 2, ebonus /= 2; score += make_score(mbonus, ebonus) + PassedFile[file_of(s)]; } @@ -682,7 +682,6 @@ namespace { if (DoTrace) Trace::add(PASSED, Us, score); - // Add the scores to the middlegame and endgame eval return score; } @@ -717,12 +716,11 @@ namespace { // 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)); - bonus = std::min(16, bonus); - int weight = pos.count(Us) - 2 * ei.pi->open_files(); + int weight = pos.count(Us) - 2 * ei.pe->open_files(); - return make_score(bonus * weight * weight / 18, 0); + return make_score(bonus * weight * weight / 16, 0); } @@ -733,15 +731,15 @@ namespace { int kingDistance = distance(pos.square(WHITE), pos.square(BLACK)) - distance(pos.square(WHITE), pos.square(BLACK)); - int pawns = pos.count(WHITE) + pos.count(BLACK); + bool bothFlanks = (pos.pieces(PAWN) & QueenSide) && (pos.pieces(PAWN) & KingSide); // Compute the initiative bonus for the attacking side - int initiative = 8 * (asymmetry + kingDistance - 15) + 12 * pawns; + int initiative = 8 * (asymmetry + kingDistance - 17) + 12 * pos.count() + 16 * bothFlanks; // 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)); + // that the endgame score will never change sign after the bonus. + int value = ((eg > 0) - (eg < 0)) * std::max(initiative, -abs(eg)); return make_score(0, value); } @@ -755,8 +753,7 @@ namespace { // 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.me->game_phase() < PHASE_MIDGAME - && (sf == SCALE_FACTOR_NORMAL || sf == SCALE_FACTOR_ONEPAWN)) + if (sf == SCALE_FACTOR_NORMAL || sf == SCALE_FACTOR_ONEPAWN) { if (pos.opposite_bishops()) { @@ -764,19 +761,18 @@ namespace { // is almost a draw, in case of KBP vs KB, it 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(31) : ScaleFactor(9); + return 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(46); + return ScaleFactor(46); } // Endings where weaker side can place his king in front of the opponent's // pawns are drawish. else if ( abs(eg) <= BishopValueEg && pos.count(strongSide) <= 2 && !pos.pawn_passed(~strongSide, pos.square(~strongSide))) - sf = ScaleFactor(37 + 7 * pos.count(strongSide)); + return ScaleFactor(37 + 7 * pos.count(strongSide)); } return sf; @@ -794,6 +790,7 @@ Value Eval::evaluate(const Position& pos) { assert(!pos.checkers()); Score mobility[COLOR_NB] = { SCORE_ZERO, SCORE_ZERO }; + Value v; EvalInfo ei; // Probe the material hash table @@ -810,31 +807,20 @@ Value Eval::evaluate(const Position& pos) { Score score = pos.psq_score() + ei.me->imbalance(); // Probe the pawn hash table - ei.pi = Pawns::probe(pos); - score += ei.pi->pawns_score(); + ei.pe = Pawns::probe(pos); + score += ei.pe->pawns_score(); + + // Early exit if score is high + v = (mg_value(score) + eg_value(score)) / 2; + if (abs(v) > LazyThreshold) + return pos.side_to_move() == WHITE ? v : -v; // 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(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 - // 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 += evaluate_pieces(pos, ei, mobility); score += mobility[WHITE] - mobility[BLACK]; // Evaluate kings after all other pieces because we need full attack @@ -847,23 +833,23 @@ Value Eval::evaluate(const Position& pos) { - evaluate_threats(pos, ei); // Evaluate passed pawns, we need full attack information including king - score += evaluate_passed_pawns(pos, ei) - - evaluate_passed_pawns(pos, ei); + score += evaluate_passer_pawns(pos, ei) + - evaluate_passer_pawns(pos, ei); // Evaluate space for both sides, only during opening - if (pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) >= 12222) + if (pos.non_pawn_material() >= SpaceThreshold) score += evaluate_space(pos, ei) - evaluate_space(pos, ei); // Evaluate position potential for the winning side - score += evaluate_initiative(pos, ei.pi->pawn_asymmetry(), eg_value(score)); + score += evaluate_initiative(pos, ei.pe->pawn_asymmetry(), eg_value(score)); // Evaluate scale factor for the winning side ScaleFactor sf = evaluate_scale_factor(pos, ei, eg_value(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 = 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); @@ -872,9 +858,9 @@ Value Eval::evaluate(const Position& pos) { { Trace::add(MATERIAL, pos.psq_score()); Trace::add(IMBALANCE, ei.me->imbalance()); - Trace::add(PAWN, ei.pi->pawns_score()); + Trace::add(PAWN, ei.pe->pawns_score()); Trace::add(MOBILITY, mobility[WHITE], mobility[BLACK]); - if (pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) >= 12222) + if (pos.non_pawn_material() >= SpaceThreshold) Trace::add(SPACE, evaluate_space(pos, ei) , evaluate_space(pos, ei)); Trace::add(TOTAL, score);