// Strength of pawn shelter for our king by [distance from edge][rank].
// RANK_1 = 0 is used for files where we have no pawn, or pawn is behind our king.
constexpr Value ShelterStrength[int(FILE_NB) / 2][RANK_NB] = {
- { V( -3), V( 81), V( 93), V( 58), V( 39), V( 18), V( 25) },
- { V(-40), V( 61), V( 35), V(-49), V(-29), V(-11), V( -63) },
- { V( -7), V( 75), V( 23), V( -2), V( 32), V( 3), V( -45) },
- { V(-36), V(-13), V(-29), V(-52), V(-48), V(-67), V(-166) }
+ { V( -6), V( 81), V( 93), V( 58), V( 39), V( 18), V( 25) },
+ { V(-43), V( 61), V( 35), V(-49), V(-29), V(-11), V( -63) },
+ { V(-10), V( 75), V( 23), V( -2), V( 32), V( 3), V( -45) },
+ { V(-39), V(-13), V(-29), V(-52), V(-48), V(-67), V(-166) }
};
// Danger of enemy pawns moving toward our king by [distance from edge][rank].
Bitboard ourPawns = b & pos.pieces(Us);
Bitboard theirPawns = b & pos.pieces(Them);
- Value safety = (ourPawns & file_bb(ksq)) ? Value(5) : Value(-5);
-
- if (shift<Down>(theirPawns) & (FileABB | FileHBB) & BlockRanks & ksq)
- safety += Value(374);
+ Value safety = (shift<Down>(theirPawns) & (FileABB | FileHBB) & BlockRanks & ksq) ?
+ Value(374) : Value(5);
File center = std::max(FILE_B, std::min(FILE_G, file_of(ksq)));
for (File f = File(center - 1); f <= File(center + 1); ++f)