// game, indexed by piece type and number of attacked squares in the MobilityArea.
const Score MobilityBonus[][32] = {
{}, {},
- { S(-75,-76), S(-56,-54), S(- 9,-26), S( -2,-10), S( 6, 5), S( 15, 11), // Knights
+ { S(-75,-76), S(-56,-54), S( -9,-26), S( -2,-10), S( 6, 5), S( 15, 11), // Knights
S( 22, 26), S( 30, 28), S( 36, 29) },
{ S(-48,-58), S(-21,-19), S( 16, -2), S( 26, 12), S( 37, 22), S( 51, 42), // Bishops
S( 54, 54), S( 63, 58), S( 65, 63), S( 71, 70), S( 79, 74), S( 81, 86),
const Score BishopPawns = S( 8, 12);
const Score RookOnPawn = S( 8, 24);
const Score TrappedRook = S(92, 0);
+ const Score CloseEnemies = S( 7, 0);
const Score SafeCheck = S(20, 20);
const Score OtherCheck = S(10, 10);
const Score ThreatByHangingPawn = S(71, 61);
// in KingDanger[]. Various little "meta-bonuses" measuring the strength
// of the enemy attack are added up into an integer, which is used as an
// index to KingDanger[].
- Score KingDanger[512];
+ Score KingDanger[400];
// KingAttackWeights[PieceType] contains king attack weights by piece type
const int KingAttackWeights[PIECE_TYPE_NB] = { 0, 0, 7, 5, 4, 1 };
if (Pt == QUEEN)
{
// Penalty if any relative pin or discovered attack against the queen
- if (pos.slider_blockers(pos.pieces(), pos.pieces(Them, ROOK, BISHOP), s))
+ if (pos.slider_blockers(pos.pieces(Them, ROOK, BISHOP), s))
score -= WeakQueen;
}
}
// evaluate_king() assigns bonuses and penalties to a king of a given color
+ const Bitboard WhiteCamp = Rank1BB | Rank2BB | Rank3BB | Rank4BB | Rank5BB;
+ const Bitboard BlackCamp = Rank8BB | Rank7BB | Rank6BB | Rank5BB | Rank4BB;
+ const Bitboard QueenSide = FileABB | FileBBB | FileCBB | FileDBB;
+ const Bitboard CenterFiles = FileCBB | FileDBB | FileEBB | FileFBB;
+ const Bitboard KingSide = FileEBB | FileFBB | FileGBB | FileHBB;
+
+ const Bitboard KingFlank[COLOR_NB][FILE_NB] = {
+ { QueenSide & WhiteCamp, QueenSide & WhiteCamp, QueenSide & WhiteCamp, CenterFiles & WhiteCamp,
+ CenterFiles & WhiteCamp, KingSide & WhiteCamp, KingSide & WhiteCamp, KingSide & WhiteCamp },
+ { QueenSide & BlackCamp, QueenSide & BlackCamp, QueenSide & BlackCamp, CenterFiles & BlackCamp,
+ CenterFiles & BlackCamp, KingSide & BlackCamp, KingSide & BlackCamp, KingSide & BlackCamp },
+ };
+
template<Color Us, bool DoTrace>
Score evaluate_king(const Position& pos, const EvalInfo& ei) {
score -= KingDanger[std::max(std::min(attackUnits, 399), 0)];
}
+ // King tropism: firstly, find squares that opponent attacks in our king flank
+ b = ei.attackedBy[Them][ALL_PIECES] & KingFlank[Us][file_of(ksq)];
+
+ assert(((Us == WHITE ? b << 4 : b >> 4) & b) == 0);
+ assert(popcount(Us == WHITE ? b << 4 : b >> 4) == popcount(b));
+
+ // Secondly, add the squares which are attacked twice in that flank and
+ // which are not defended by our pawns.
+ b = (Us == WHITE ? b << 4 : b >> 4)
+ | (b & ei.attackedBy2[Them] & ~ei.attackedBy[Us][PAWN]);
+
+ score -= CloseEnemies * popcount(b);
+
if (DoTrace)
Trace::add(KING, Us, score);
// evaluate_threats() assigns bonuses according to the types of the attacking
// and the attacked pieces.
- const Bitboard WhiteCamp = Rank4BB | Rank5BB | Rank6BB | Rank7BB | Rank8BB;
- const Bitboard BlackCamp = Rank5BB | Rank4BB | Rank3BB | Rank2BB | Rank1BB;
- const Bitboard QueenSide = FileABB | FileBBB | FileCBB | FileDBB;
- const Bitboard CenterFiles = FileCBB | FileDBB | FileEBB | FileFBB;
- const Bitboard KingSide = FileEBB | FileFBB | FileGBB | FileHBB;
-
- const Bitboard KingFlank[COLOR_NB][FILE_NB] = {
- { QueenSide & WhiteCamp, QueenSide & WhiteCamp, QueenSide & WhiteCamp, CenterFiles & WhiteCamp,
- CenterFiles & WhiteCamp, KingSide & WhiteCamp, KingSide & WhiteCamp, KingSide & WhiteCamp },
- { QueenSide & BlackCamp, QueenSide & BlackCamp, QueenSide & BlackCamp, CenterFiles & BlackCamp,
- CenterFiles & BlackCamp, KingSide & BlackCamp, KingSide & BlackCamp, KingSide & BlackCamp },
- };
-
template<Color Us, bool DoTrace>
Score evaluate_threats(const Position& pos, const EvalInfo& ei) {
score += ThreatByPawnPush * popcount(b);
- // King tropism: firstly, find squares that we attack in the enemy king flank
- b = ei.attackedBy[Us][ALL_PIECES] & KingFlank[Us][file_of(pos.square<KING>(Them))];
-
- // Secondly, add to the bitboard the squares which we attack twice in that flank
- // but which are not protected by a enemy pawn. Note the trick to shift away the
- // previous attack bits to the empty part of the bitboard.
- b = (b & ei.attackedBy2[Us] & ~ei.attackedBy[Them][PAWN])
- | (Us == WHITE ? b >> 4 : b << 4);
-
- // Count all these squares with a single popcount
- score += make_score(7 * popcount(b), 0);
-
if (DoTrace)
Trace::add(THREAT, Us, score);
// ...count safe + (behind & safe) with a single popcount
int bonus = popcount((Us == WHITE ? safe << 32 : safe >> 32) | (behind & safe));
- int weight = pos.count<ALL_PIECES>(Us);
+ bonus = std::min(16, bonus);
+ int weight = pos.count<ALL_PIECES>(Us) - 2 * ei.pi->open_files();
- return make_score(bonus * weight * weight / 22, 0);
+ return make_score(bonus * weight * weight / 18, 0);
}
// Endings where weaker side can place his king in front of the opponent's
// pawns are drawish.
else if ( abs(eg) <= BishopValueEg
- && ei.pi->pawn_span(strongSide) <= 1
+ && pos.count<PAWN>(strongSide) <= 2
&& !pos.pawn_passed(~strongSide, pos.square<KING>(~strongSide)))
- sf = ei.pi->pawn_span(strongSide) ? ScaleFactor(51) : ScaleFactor(37);
+ sf = ScaleFactor(37 + 7 * pos.count<PAWN>(strongSide));
}
return sf;
projects / stockfish / blobdiff