namespace {
- const Bitboard LongDiagonals = 0x8142241818244281ULL; // A1..H8 | H1..A8
- const Bitboard Center = (FileDBB | FileEBB) & (Rank4BB | Rank5BB);
- const Bitboard QueenSide = FileABB | FileBBB | FileCBB | FileDBB;
- const Bitboard CenterFiles = FileCBB | FileDBB | FileEBB | FileFBB;
- const Bitboard KingSide = FileEBB | FileFBB | FileGBB | FileHBB;
+ const Bitboard Center = (FileDBB | FileEBB) & (Rank4BB | Rank5BB);
+ const Bitboard QueenSide = FileABB | FileBBB | FileCBB | FileDBB;
+ const Bitboard CenterFiles = FileCBB | FileDBB | FileEBB | FileFBB;
+ const Bitboard KingSide = FileEBB | FileFBB | FileGBB | FileHBB;
const Bitboard KingFlank[FILE_NB] = {
QueenSide, QueenSide, QueenSide, CenterFiles, CenterFiles, KingSide, KingSide, KingSide
const Score CloseEnemies = S( 7, 0);
const Score PawnlessFlank = S( 20, 80);
const Score ThreatByHangingPawn = S( 71, 61);
- const Score ThreatBySafePawn = S(182,175);
+ const Score ThreatBySafePawn = S(192,175);
const Score ThreatByRank = S( 16, 3);
const Score Hanging = S( 48, 27);
const Score WeakUnopposedPawn = S( 5, 25);
// Penalty for pawns on the same color square as the bishop
score -= BishopPawns * pe->pawns_on_same_color_squares(Us, s);
- // Bonus for bishop on a long diagonal without pawns in the center
- if ( (LongDiagonals & s)
- && !(attackedBy[Them][PAWN] & s)
- && !(Center & PseudoAttacks[BISHOP][s] & pos.pieces(PAWN)))
+ // Bonus for bishop on a long diagonal which can "see" both center squares
+ if (more_than_one(Center & (attacks_bb<BISHOP>(s, pos.pieces(PAWN)) | s)))
score += LongRangedBishop;
}