// Assorted bonuses and penalties
const Score BishopPawns = S( 8, 12);
const Score CloseEnemies = S( 7, 0);
+ const Score Connectivity = S( 3, 1);
const Score Hanging = S( 52, 30);
const Score HinderPassedPawn = S( 8, 1);
+ const Score KnightOnQueen = S( 21, 11);
const Score LongRangedBishop = S( 22, 0);
const Score MinorBehindPawn = S( 16, 0);
const Score PawnlessFlank = S( 20, 80);
const Score RookOnPawn = S( 8, 24);
+ const Score SliderOnQueen = S( 42, 21);
const Score ThreatByPawnPush = S( 47, 26);
const Score ThreatByRank = S( 16, 3);
const Score ThreatBySafePawn = S(175,168);
- const Score ThreatOnQueen = S( 42, 21);
const Score TrappedBishopA1H1 = S( 50, 50);
const Score TrappedRook = S( 92, 0);
const Score WeakQueen = S( 50, 10);
// attackedBy[color][piece type] is a bitboard representing all squares
// attacked by a given color and piece type. Special "piece types" which
- // are also calculated are QUEEN_DIAGONAL and ALL_PIECES.
+ // is also calculated is ALL_PIECES.
Bitboard attackedBy[COLOR_NB][PIECE_TYPE_NB];
// attackedBy2[color] are the squares attacked by 2 pieces of a given color,
attackedBy[Us][Pt] = 0;
- if (Pt == QUEEN)
- attackedBy[Us][QUEEN_DIAGONAL] = 0;
-
while ((s = *pl++) != SQ_NONE)
{
// Find attacked squares, including x-ray attacks for bishops and rooks
attackedBy[Us][Pt] |= b;
attackedBy[Us][ALL_PIECES] |= b;
- if (Pt == QUEEN)
- attackedBy[Us][QUEEN_DIAGONAL] |= b & PseudoAttacks[BISHOP][s];
-
if (b & kingRing[Them])
{
kingAttackersCount[Us]++;
if (!(pos.pieces(PAWN) & kf))
score -= PawnlessFlank;
- // Find the squares that opponent attacks in our king flank, and the squares
+ // Find the squares that opponent attacks in our king flank, and the squares
// which are attacked twice in that flank but not defended by our pawns.
b1 = attackedBy[Them][ALL_PIECES] & kf & Camp;
b2 = b1 & attackedBy2[Them] & ~attackedBy[Us][PAWN];
score += ThreatByPawnPush * popcount(b);
- // Bonus for safe slider threats on the next move toward enemy queen
- safeThreats = ~pos.pieces(Us) & ~attackedBy2[Them] & attackedBy2[Us];
- b = (attackedBy[Us][BISHOP] & attackedBy[Them][QUEEN_DIAGONAL])
- | (attackedBy[Us][ROOK ] & attackedBy[Them][QUEEN] & ~attackedBy[Them][QUEEN_DIAGONAL]);
+ // Bonus for threats on the next moves against enemy queen
+ if (pos.count<QUEEN>(Them) == 1)
+ {
+ Square s = pos.square<QUEEN>(Them);
+ safeThreats = mobilityArea[Us] & ~stronglyProtected;
+
+ b = attackedBy[Us][KNIGHT] & pos.attacks_from<KNIGHT>(s);
+
+ score += KnightOnQueen * popcount(b & safeThreats);
- score += ThreatOnQueen * popcount(b & safeThreats);
+ b = (attackedBy[Us][BISHOP] & pos.attacks_from<BISHOP>(s))
+ | (attackedBy[Us][ROOK ] & pos.attacks_from<ROOK >(s));
+
+ score += SliderOnQueen * popcount(b & safeThreats & attackedBy2[Us]);
+ }
+
+ // Connectivity: ensure that knights, bishops, rooks, and queens are protected
+ b = (pos.pieces(Us) ^ pos.pieces(Us, PAWN, KING)) & attackedBy[Us][ALL_PIECES];
+ score += Connectivity * popcount(b);
if (T)
Trace::add(THREAT, Us, score);
behind |= (Us == WHITE ? behind >> 8 : behind << 8);
behind |= (Us == WHITE ? behind >> 16 : behind << 16);
- // Since SpaceMask[Us] is fully on our half of the board...
- assert(unsigned(safe >> (Us == WHITE ? 32 : 0)) == 0);
-
- // ...count safe + (behind & safe) with a single popcount.
- int bonus = popcount((Us == WHITE ? safe << 32 : safe >> 32) | (behind & safe));
+ int bonus = popcount(safe) + popcount(behind & safe);
int weight = pos.count<ALL_PIECES>(Us) - 2 * pe->open_files();
+
Score score = make_score(bonus * weight * weight / 16, 0);
if (T)
+ 8 * pe->pawn_asymmetry()
+ 12 * pos.count<PAWN>()
+ 16 * pawnsOnBothFlanks
+ + 48 * !pos.non_pawn_material()
-136 ;
// Now apply the bonus: note that we find the attacking side by extracting