X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fendgame.cpp;h=5958e633d90e271e9fef852014defd7d6000164b;hp=835173c468b68bed46b7159dfafe5e32d74c9b0a;hb=44c320a572188b5875291103edb344c584b91d19;hpb=eb6d7f537d214c4dc8bde7d4fdc2aaead47dd3c3 diff --git a/src/endgame.cpp b/src/endgame.cpp index 835173c4..5958e633 100644 --- a/src/endgame.cpp +++ b/src/endgame.cpp @@ -18,7 +18,6 @@ along with this program. If not, see . */ -#include #include #include "bitboard.h" @@ -77,10 +76,7 @@ namespace { if (file_of(pos.square(strongSide)) >= FILE_E) sq = Square(sq ^ 7); // Mirror SQ_H1 -> SQ_A1 - if (strongSide == BLACK) - sq = ~sq; - - return sq; + return strongSide == WHITE ? sq : ~sq; } } // namespace @@ -286,6 +282,21 @@ 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; } @@ -624,8 +635,6 @@ 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 +668,7 @@ 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