X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fevaluate.cpp;h=5621c508f219d7ed7725c68f46b4a28032973fc4;hp=0136db840f7031e5142919e9b97561d94b57496d;hb=de02768af7b37c903e3227b85ec4d81ec79ba69a;hpb=589049a0e58f5cde377e620e1669d7ce17ff5ddd diff --git a/src/evaluate.cpp b/src/evaluate.cpp index 0136db84..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 @@ -159,15 +159,18 @@ namespace { 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 + // 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) }; - // ThreatByKing[on one/on many] contains bonuses for King attacks on + 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 // pawns or pieces which are not pawn-defended. const Score ThreatByKing[2] = { S(3, 62), S(9, 138) }; @@ -181,7 +184,7 @@ 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 @@ -189,18 +192,16 @@ namespace { const Score BishopPawns = S( 8, 12); const Score RookOnPawn = S( 8, 24); const Score TrappedRook = S(92, 0); - const Score CloseEnemies = S( 7, 0); - const Score SafeCheck = S(20, 20); + const Score WeakQueen = S(50, 10); const Score OtherCheck = S(10, 10); - const Score ThreatByHangingPawn = S(71, 61); + const Score CloseEnemies = S( 7, 0); + const Score PawnlessFlank = S(20, 80); const Score LooseEnemies = S( 0, 25); - const Score WeakQueen = S(50, 10); + 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 Unstoppable = S( 0, 45); - const Score PawnlessFlank = S(20, 80); const Score HinderPassedPawn = S( 7, 0); - const Score ThreatByRank = S(16, 3); // 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 @@ -215,11 +216,13 @@ namespace { // Penalties for enemy's safe checks const int QueenContactCheck = 997; - const int QueenCheck = 695; - const int RookCheck = 638; - const int BishopCheck = 538; - const int KnightCheck = 874; + 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. @@ -240,8 +243,7 @@ namespace { if (pos.non_pawn_material(Us) >= QueenValueMg) { ei.kingRing[Them] = b | shift(b); - b &= ei.attackedBy[Us][PAWN]; - ei.kingAttackersCount[Us] = popcount(b); + ei.kingAttackersCount[Us] = popcount(b & ei.attackedBy[Us][PAWN]); ei.kingAdjacentZoneAttacksCount[Us] = ei.kingAttackersWeight[Us] = 0; } else @@ -255,16 +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) @@ -378,28 +380,24 @@ 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 }, + 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 Square Up = (Us == WHITE ? NORTH : SOUTH); + 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); + const Square ksq = pos.square(Us); Bitboard undefended, b, b1, b2, safe, other; int kingDanger; - const Square ksq = pos.square(Us); // King shelter and enemy pawns storm Score score = ei.pi->king_safety(pos, ksq); @@ -448,7 +446,7 @@ namespace { // Enemy queen safe checks if ((b1 | b2) & ei.attackedBy[Them][QUEEN] & safe) - kingDanger += QueenCheck, score -= SafeCheck; + kingDanger += QueenCheck; // For other pieces, also consider the square safe if attacked twice, // and only defended by a queen. @@ -458,14 +456,14 @@ namespace { // Enemy rooks safe and other checks if (b1 & ei.attackedBy[Them][ROOK] & safe) - kingDanger += RookCheck, score -= SafeCheck; + kingDanger += RookCheck; else if (b1 & ei.attackedBy[Them][ROOK] & other) score -= OtherCheck; // Enemy bishops safe and other checks if (b2 & ei.attackedBy[Them][BISHOP] & safe) - kingDanger += BishopCheck, score -= SafeCheck; + kingDanger += BishopCheck; else if (b2 & ei.attackedBy[Them][BISHOP] & other) score -= OtherCheck; @@ -473,7 +471,7 @@ namespace { // Enemy knights safe and other checks b = pos.attacks_from(ksq) & ei.attackedBy[Them][KNIGHT]; if (b & safe) - kingDanger += KnightCheck, score -= SafeCheck; + kingDanger += KnightCheck; else if (b & other) score -= OtherCheck; @@ -485,7 +483,7 @@ namespace { // King tropism: firstly, find squares that opponent attacks in our king flank File kf = file_of(ksq); - b = ei.attackedBy[Them][ALL_PIECES] & KingFlank[Us][kf]; + 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)); @@ -498,7 +496,7 @@ namespace { score -= CloseEnemies * popcount(b); // Penalty when our king is on a pawnless flank - if (!(pos.pieces(PAWN) & (KingFlank[WHITE][kf] | KingFlank[BLACK][kf]))) + if (!(pos.pieces(PAWN) & KingFlank[kf])) score -= PawnlessFlank; if (DoTrace) @@ -521,8 +519,6 @@ namespace { const Bitboard TRank2BB = (Us == WHITE ? Rank2BB : Rank7BB); const Bitboard TRank7BB = (Us == WHITE ? Rank7BB : Rank2BB); - enum { Minor, Rook }; - Bitboard b, weak, defended, safeThreats; Score score = SCORE_ZERO; @@ -563,7 +559,7 @@ namespace { while (b) { Square s = pop_lsb(&b); - score += Threat[Minor][type_of(pos.piece_on(s))]; + score += ThreatByMinor[type_of(pos.piece_on(s))]; if (type_of(pos.piece_on(s)) != PAWN) score += ThreatByRank * (int)relative_rank(Them, s); } @@ -572,7 +568,7 @@ namespace { while (b) { Square s = pop_lsb(&b); - score += Threat[Rook][type_of(pos.piece_on(s))]; + score += ThreatByRook[type_of(pos.piece_on(s))]; if (type_of(pos.piece_on(s)) != PAWN) score += ThreatByRank * (int)relative_rank(Them, s); } @@ -678,6 +674,10 @@ 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; + score += make_score(mbonus, ebonus) + PassedFile[file_of(s)]; } @@ -700,8 +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 @@ -784,6 +784,18 @@ namespace { 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 @@ -815,6 +827,12 @@ Value Eval::evaluate(const Position& pos) { 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)); @@ -852,16 +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)) - { - if (ei.pi->passed_pawns(WHITE)) - score += Unstoppable; - - if (ei.pi->passed_pawns(BLACK)) - score -= Unstoppable; - } - // 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)