X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fevaluate.cpp;h=057fd70c8216ec5fd4cae5d212b76d760a5ca0fc;hp=e4ade31aacc7535ca979d5bcfc23ab8dc910b965;hb=2ee125029420b46b255116ab1d57931a9d6cf3e4;hpb=7d42752158e491989e31b6fc0eb011c863f7628b diff --git a/src/evaluate.cpp b/src/evaluate.cpp index e4ade31a..057fd70c 100644 --- a/src/evaluate.cpp +++ b/src/evaluate.cpp @@ -27,7 +27,6 @@ #include "material.h" #include "pawns.h" #include "thread.h" -#include "uci.h" namespace { @@ -499,12 +498,11 @@ namespace { assert(target & (pos.pieces(C) ^ pos.pieces(C, KING))); - PieceType pt; - for (pt = QUEEN; pt > PAWN; --pt) + for (PieceType pt = QUEEN; pt > PAWN; --pt) if (target & pos.pieces(C, pt)) return pt; - return pt; + return PAWN; } @@ -767,27 +765,25 @@ namespace { if ( ei.mi->game_phase() < PHASE_MIDGAME && (sf == SCALE_FACTOR_NORMAL || sf == SCALE_FACTOR_ONEPAWN)) { - if (pos.opposite_bishops()) { - // Ignoring any pawns, do both sides only have a single bishop and no - // other pieces? + if (pos.opposite_bishops()) + { + // Endgame with opposite-colored bishops and no other pieces (ignoring pawns) + // is almost a draw, in case of KBP vs KB is even more a draw. if ( pos.non_pawn_material(WHITE) == BishopValueMg && pos.non_pawn_material(BLACK) == BishopValueMg) - { - // Check for KBP vs KB with only a single pawn that is almost - // certainly a draw or at least two pawns. - bool one_pawn = (pos.count(WHITE) + pos.count(BLACK) == 1); - sf = one_pawn ? ScaleFactor(8) : ScaleFactor(32); - } + sf = more_than_one(pos.pieces(PAWN)) ? ScaleFactor(32) : ScaleFactor(8); + + // Endgame with opposite-colored bishops, but also other pieces. Still + // a bit drawish, but not as drawish as with only the two bishops. else - // Endgame with opposite-colored bishops, but also other pieces. Still - // a bit drawish, but not as drawish as with only the two bishops. sf = ScaleFactor(50 * sf / SCALE_FACTOR_NORMAL); - } else if ( abs(eg_value(score)) <= BishopValueEg - && ei.pi->pawn_span(strongSide) <= 1 - && !pos.pawn_passed(~strongSide, pos.king_square(~strongSide))) { - // Endings where weaker side can be place his king in front of the opponent's pawns are drawish. - sf = ScaleFactor(ScalePawnSpan[ei.pi->pawn_span(strongSide)]); } + // Endings where weaker side can place his king in front of the opponent's + // pawns are drawish. + else if ( abs(eg_value(score)) <= BishopValueEg + && ei.pi->pawn_span(strongSide) <= 1 + && !pos.pawn_passed(~strongSide, pos.king_square(~strongSide))) + sf = ScaleFactor(ScalePawnSpan[ei.pi->pawn_span(strongSide)]); } // Interpolate between a middlegame and a (scaled by 'sf') endgame score @@ -906,8 +902,7 @@ namespace Eval { } - /// init() computes evaluation weights from the corresponding UCI parameters - /// and setup king tables. + /// init() computes evaluation weights. void init() {