X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fendgame.cpp;h=276b942eac55642a3ac3212b6152f797462816bc;hp=66ee54d846044c90d03ec4dcaf9699e07aae13ee;hb=bae019b53e5c2bfcf0d69b4ebfc52b4f4de762eb;hpb=96ac85b3196ed7369a91a0852da0adcaf05a04b3 diff --git a/src/endgame.cpp b/src/endgame.cpp index 66ee54d8..276b942e 100644 --- a/src/endgame.cpp +++ b/src/endgame.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) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad + Copyright (C) 2015-2020 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 @@ -18,7 +18,6 @@ along with this program. If not, see . */ -#include #include #include "bitboard.h" @@ -75,17 +74,42 @@ namespace { assert(pos.count(strongSide) == 1); if (file_of(pos.square(strongSide)) >= FILE_E) - sq = Square(sq ^ 7); // Mirror SQ_H1 -> SQ_A1 + sq = Square(int(sq) ^ 7); // Mirror SQ_H1 -> SQ_A1 - if (strongSide == BLACK) - sq = ~sq; - - return sq; + return strongSide == WHITE ? sq : ~sq; } } // namespace +namespace Endgames { + + std::pair, Map> maps; + + void init() { + + add("KPK"); + add("KNNK"); + add("KBNK"); + add("KRKP"); + add("KRKB"); + add("KRKN"); + add("KQKP"); + add("KQKR"); + add("KNNKP"); + + add("KNPK"); + add("KNPKB"); + add("KRPKR"); + add("KRPKB"); + add("KBPKB"); + add("KBPKN"); + add("KBPPKB"); + add("KRPPKRP"); + } +} + + /// Mate with KX vs K. This function is used to evaluate positions with /// king and plenty of material vs a lone king. It simply gives the /// attacking side a bonus for driving the defending king towards the edge @@ -131,7 +155,7 @@ Value Endgame::operator()(const Position& pos) const { Square loserKSq = pos.square(weakSide); Square bishopSq = pos.square(strongSide); - // If our Bishop does not attack A1/H8, we flip the enemy king square + // If our Bishop does not attack A1/H8, we flip the enemy king square // to drive to opposite corners (A8/H1). Value result = VALUE_KNOWN_WIN @@ -286,6 +310,21 @@ Value Endgame::operator()(const Position& pos) const { } +/// KNN vs KP. Simply push the opposing king to the corner +template<> +Value Endgame::operator()(const Position& pos) const { + + assert(verify_material(pos, strongSide, 2 * KnightValueMg, 0)); + assert(verify_material(pos, weakSide, VALUE_ZERO, 1)); + + Value result = 2 * KnightValueEg + - PawnValueEg + + PushToEdges[pos.square(weakSide)]; + + return strongSide == pos.side_to_move() ? result : -result; +} + + /// Some cases of trivial draws template<> Value Endgame::operator()(const Position&) const { return VALUE_DRAW; } @@ -326,7 +365,7 @@ ScaleFactor Endgame::operator()(const Position& pos) const { && pos.count(weakSide) >= 1) { // Get weakSide pawn that is closest to the home rank - Square weakPawnSq = backmost_sq(weakSide, pos.pieces(weakSide, PAWN)); + Square weakPawnSq = frontmost_sq(strongSide, pos.pieces(weakSide, PAWN)); Square strongKingSq = pos.square(strongSide); Square weakKingSq = pos.square(weakSide); @@ -624,8 +663,6 @@ ScaleFactor Endgame::operator()(const Position& pos) const { Square ksq = pos.square(weakSide); Square psq1 = pos.squares(strongSide)[0]; Square psq2 = pos.squares(strongSide)[1]; - Rank r1 = rank_of(psq1); - Rank r2 = rank_of(psq2); Square blockSq1, blockSq2; if (relative_rank(strongSide, psq1) > relative_rank(strongSide, psq2)) @@ -659,7 +696,7 @@ ScaleFactor Endgame::operator()(const Position& pos) const { && opposite_colors(ksq, wbsq) && ( bbsq == blockSq2 || (pos.attacks_from(blockSq2) & pos.pieces(weakSide, BISHOP)) - || distance(r1, r2) >= 2)) + || distance(psq1, psq2) >= 2)) return SCALE_FACTOR_DRAW; else if ( ksq == blockSq2 @@ -724,6 +761,9 @@ ScaleFactor Endgame::operator()(const Position& pos) const { template<> ScaleFactor Endgame::operator()(const Position& pos) const { + assert(verify_material(pos, strongSide, KnightValueMg, 1)); + assert(verify_material(pos, weakSide, BishopValueMg, 0)); + Square pawnSq = pos.square(strongSide); Square bishopSq = pos.square(weakSide); Square weakKingSq = pos.square(weakSide);