X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;ds=sidebyside;f=src%2Fevaluate.cpp;h=f6beca356bc5f0eb7cc6b66012c0a5a12890c2cc;hb=69067e1988ea945977d586a1442a22be0b55671a;hp=47a65c592cdfb7ef3456f27e99cca109ebb5ae0d;hpb=be6fafd0793d934c31925832b4bde569b5abd5b9;p=stockfish diff --git a/src/evaluate.cpp b/src/evaluate.cpp index 47a65c59..f6beca35 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) 2015-2017 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad + Copyright (C) 2015-2018 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 @@ -97,6 +97,7 @@ namespace { template void initialize(); template Score evaluate_king(); template Score evaluate_threats(); + int king_distance(Color c, Square s); template Score evaluate_passed_pawns(); template Score evaluate_space(); template Score evaluate_pieces(); @@ -198,8 +199,8 @@ namespace { // 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(5), V( 5), V(31), V(73), V(166), V(252) }, - { V(7), V(14), V(38), V(73), V(166), V(252) } + { V(0), V(5), V( 5), V(31), V(73), V(166), V(252) }, + { V(0), V(7), V(14), V(38), V(73), V(166), V(252) } }; // PassedFile[File] contains a bonus according to the file of a passed pawn @@ -208,6 +209,9 @@ namespace { S(-20,-12), S( 1, -8), S( 2, 10), S( 9, 10) }; + // Rank factor applied on some bonus for passed pawn on rank 4 or beyond + const int RankFactor[RANK_NB] = {0, 0, 0, 2, 6, 11, 16}; + // 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) }; @@ -220,7 +224,6 @@ namespace { const Score WeakQueen = S( 50, 10); const Score CloseEnemies = S( 7, 0); const Score PawnlessFlank = S( 20, 80); - const Score ThreatByHangingPawn = S( 71, 61); const Score ThreatBySafePawn = S(192,175); const Score ThreatByRank = S( 16, 3); const Score Hanging = S( 48, 27); @@ -310,8 +313,8 @@ namespace { while ((s = *pl++) != SQ_NONE) { // Find attacked squares, including x-ray attacks for bishops and rooks - b = Pt == BISHOP ? attacks_bb(s, pos.pieces() ^ pos.pieces(Us, QUEEN)) - : Pt == ROOK ? attacks_bb< ROOK>(s, pos.pieces() ^ pos.pieces(Us, ROOK, QUEEN)) + b = Pt == BISHOP ? attacks_bb(s, pos.pieces() ^ pos.pieces(QUEEN)) + : Pt == ROOK ? attacks_bb< ROOK>(s, pos.pieces() ^ pos.pieces(QUEEN) ^ pos.pieces(Us, ROOK)) : pos.attacks_from(s); if (pos.pinned_pieces(Us) & s) @@ -487,9 +490,13 @@ namespace { - 9 * mg_value(score) / 8 + 40; - // Transform the kingDanger units into a Score, and substract it from the evaluation + // Transform the kingDanger units into a Score, and subtract it from the evaluation if (kingDanger > 0) + { + int mobilityDanger = mg_value(mobility[Them] - mobility[Us]); + kingDanger = std::max(0, kingDanger + mobilityDanger); score -= make_score(kingDanger * kingDanger / 4096, kingDanger / 16); + } } // King tropism: firstly, find squares that opponent attacks in our king flank @@ -543,9 +550,6 @@ namespace { safeThreats = (shift(b) | shift(b)) & weak; score += ThreatBySafePawn * popcount(safeThreats); - - if (weak ^ safeThreats) - score += ThreatByHangingPawn; } // Squares strongly protected by the opponent, either because they attack the @@ -622,6 +626,12 @@ namespace { return score; } + // king_distance() returns an estimate of the distance that the king + // of the given color has to run to reach square s. + template + int Evaluation::king_distance(Color c, Square s) { + return std::min(distance(pos.square(c), s), 5); + } // evaluate_passed_pawns() evaluates the passed pawns and candidate passed // pawns of the given color. @@ -646,8 +656,8 @@ namespace { bb = forward_file_bb(Us, s) & (attackedBy[Them][ALL_PIECES] | pos.pieces(Them)); score -= HinderPassedPawn * popcount(bb); - int r = relative_rank(Us, s) - RANK_2; - int rr = r * (r - 1); + int r = relative_rank(Us, s); + int rr = RankFactor[r]; Value mbonus = Passed[MG][r], ebonus = Passed[EG][r]; @@ -656,12 +666,11 @@ namespace { Square blockSq = s + Up; // Adjust bonus based on the king's proximity - ebonus += distance(pos.square(Them), blockSq) * 5 * rr - - distance(pos.square( Us), blockSq) * 2 * rr; + ebonus += (king_distance(Them, blockSq) * 5 - king_distance(Us, blockSq) * 2) * rr; // If blockSq is not the queening square then consider also a second push - if (relative_rank(Us, blockSq) != RANK_8) - ebonus -= distance(pos.square(Us), blockSq + Up) * rr; + if (r != RANK_7) + ebonus -= king_distance(Us, blockSq + Up) * rr; // If the pawn is free to advance, then increase the bonus if (pos.empty(blockSq)) @@ -891,7 +900,7 @@ namespace { Trace::add(TOTAL, score); } - return (pos.side_to_move() == WHITE ? v : -v) + Eval::Tempo; // Side to move point of view + return pos.side_to_move() == WHITE ? v : -v; // Side to move point of view } } // namespace @@ -903,7 +912,7 @@ Score Eval::Contempt = SCORE_ZERO; Value Eval::evaluate(const Position& pos) { - return Evaluation<>(pos).value(); + return Evaluation<>(pos).value() + Eval::Tempo; } /// trace() is like evaluate(), but instead of returning a value, it returns @@ -914,7 +923,7 @@ std::string Eval::trace(const Position& pos) { std::memset(scores, 0, sizeof(scores)); - Value v = Evaluation(pos).value(); + Value v = Evaluation(pos).value() + Eval::Tempo; v = pos.side_to_move() == WHITE ? v : -v; // White's point of view std::stringstream ss;