// PassedRank[Rank] contains a bonus according to the rank of a passed pawn
constexpr Score PassedRank[RANK_NB] = {
- S(0, 0), S(5, 7), S(5, 13), S(32, 42), S(70, 70), S(172, 170), S(217, 269)
+ S(0, 0), S(5, 7), S(5, 13), S(18, 23), S(74, 58), S(164, 166), S(268, 243)
};
// PassedFile[File] contains a bonus according to the file of a passed pawn
constexpr Score PassedFile[FILE_NB] = {
- S( 9, 10), S(2, 10), S(1, -8), S(-20,-12),
- S(-20,-12), S(1, -8), S(2, 10), S( 9, 10)
+ S( 15, 7), S(-5, 14), S( 1, -5), S(-22,-11),
+ S(-22,-11), S( 1, -5), S(-5, 14), S( 15, 7)
};
// PassedDanger[Rank] contains a term to weight the passed score
- constexpr int PassedDanger[RANK_NB] = { 0, 0, 0, 2, 7, 12, 19 };
+ constexpr int PassedDanger[RANK_NB] = { 0, 0, 0, 3, 6, 12, 21 };
// KingProtector[PieceType-2] contains a penalty according to distance from king
constexpr Score KingProtector[] = { S(3, 5), S(4, 3), S(3, 0), S(1, -1) };
// Assorted bonuses and penalties
- constexpr Score BishopPawns = S( 8, 12);
+ constexpr Score BishopPawns = S( 3, 5);
constexpr Score CloseEnemies = S( 7, 0);
constexpr Score Connectivity = S( 3, 1);
constexpr Score CorneredBishop = S( 50, 50);
constexpr Score KnightOnQueen = S( 21, 11);
constexpr Score LongDiagonalBishop = S( 22, 0);
constexpr Score MinorBehindPawn = S( 16, 0);
+ constexpr Score Overload = S( 10, 5);
constexpr Score PawnlessFlank = S( 20, 80);
constexpr Score RookOnPawn = S( 8, 24);
constexpr Score SliderOnQueen = S( 42, 21);
// Find our pawns that are blocked or on the first two ranks
Bitboard b = pos.pieces(Us, PAWN) & (shift<Down>(pos.pieces()) | LowRanks);
- // Squares occupied by those pawns, by our king, or controlled by enemy pawns
+ // Squares occupied by those pawns, by our king or queen, or controlled by enemy pawns
// are excluded from the mobility area.
- mobilityArea[Us] = ~(b | pos.square<KING>(Us) | pe->pawn_attacks(Them));
+ mobilityArea[Us] = ~(b | pos.pieces(Us, KING, QUEEN) | pe->pawn_attacks(Them));
// Initialise attackedBy bitboards for kings and pawns
attackedBy[Us][KING] = pos.attacks_from<KING>(pos.square<KING>(Us));
template<Tracing T> template<Color Us, PieceType Pt>
Score Evaluation<T>::pieces() {
- constexpr Color Them = (Us == WHITE ? BLACK : WHITE);
+ constexpr Color Them = (Us == WHITE ? BLACK : WHITE);
+ constexpr Direction Down = (Us == WHITE ? SOUTH : NORTH);
constexpr Bitboard OutpostRanks = (Us == WHITE ? Rank4BB | Rank5BB | Rank6BB
: Rank5BB | Rank4BB | Rank3BB);
const Square* pl = pos.squares<Pt>(Us);
if (Pt == BISHOP)
{
- // Penalty according to number of pawns on the same color square as the bishop
- score -= BishopPawns * pe->pawns_on_same_color_squares(Us, s);
+ // Penalty according to number of pawns on the same color square as the
+ // bishop, bigger when the center files are blocked with pawns.
+ Bitboard blocked = pos.pieces(Us, PAWN) & shift<Down>(pos.pieces());
+
+ score -= BishopPawns * pe->pawns_on_same_color_squares(Us, s)
+ * (1 + popcount(blocked & CenterFiles));
// 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)))
: AllSquares ^ Rank1BB ^ Rank2BB ^ Rank3BB);
const Square ksq = pos.square<KING>(Us);
- Bitboard weak, b, b1, b2, safe, unsafeChecks, pinned;
+ Bitboard weak, b, b1, b2, safe, unsafeChecks;
// King shelter and enemy pawns storm
Score score = pe->king_safety<Us>(pos, ksq);
// Unsafe or occupied checking squares will also be considered, as long as
// the square is in the attacker's mobility area.
unsafeChecks &= mobilityArea[Them];
- pinned = pos.blockers_for_king(Us) & pos.pieces(Us);
kingDanger += kingAttackersCount[Them] * kingAttackersWeight[Them]
+ 102 * kingAttacksCount[Them]
+ 191 * popcount(kingRing[Us] & weak)
- + 143 * popcount(pinned | unsafeChecks)
+ + 143 * popcount(pos.blockers_for_king(Us) | unsafeChecks)
- 848 * !pos.count<QUEEN>(Them)
- 9 * mg_value(score) / 8
+ 40;
Bitboard b, weak, defended, nonPawnEnemies, stronglyProtected, safeThreats;
Score score = SCORE_ZERO;
- // Non-pawn enemies attacked by a pawn
+ // Non-pawn enemies
nonPawnEnemies = pos.pieces(Them) ^ pos.pieces(Them, PAWN);
- // Our safe or protected pawns
- b = pos.pieces(Us, PAWN)
- & (~attackedBy[Them][ALL_PIECES] | attackedBy[Us][ALL_PIECES]);
-
- safeThreats = pawn_attacks_bb<Us>(b) & nonPawnEnemies;
- score += ThreatBySafePawn * popcount(safeThreats);
-
// Squares strongly protected by the enemy, either because they defend the
// square with a pawn, or because they defend the square twice and we don't.
stronglyProtected = attackedBy[Them][PAWN]
score += ThreatByRank * (int)relative_rank(Them, s);
}
- score += Hanging * popcount(weak & ~attackedBy[Them][ALL_PIECES]);
-
b = weak & attackedBy[Us][KING];
if (b)
score += ThreatByKing[more_than_one(b)];
+
+ score += Hanging * popcount(weak & ~attackedBy[Them][ALL_PIECES]);
+
+ // Bonus for overload (non-pawn enemies attacked and defended exactly once)
+ b = nonPawnEnemies
+ & attackedBy[Us][ALL_PIECES] & ~attackedBy2[Us]
+ & attackedBy[Them][ALL_PIECES] & ~attackedBy2[Them];
+ score += Overload * popcount(b);
}
// Bonus for enemy unopposed weak pawns
if (pos.pieces(Us, ROOK, QUEEN))
score += WeakUnopposedPawn * pe->weak_unopposed(Them);
+ // Our safe or protected pawns
+ b = pos.pieces(Us, PAWN)
+ & (~attackedBy[Them][ALL_PIECES] | attackedBy[Us][ALL_PIECES]);
+
+ safeThreats = pawn_attacks_bb<Us>(b) & nonPawnEnemies;
+ score += ThreatBySafePawn * popcount(safeThreats);
+
// Find squares where our pawns can push on the next move
b = shift<Up>(pos.pieces(Us, PAWN)) & ~pos.pieces();
b |= shift<Up>(b & TRank3BB) & ~pos.pieces();
} // w != 0
// Scale down bonus for candidate passers which need more than one
- // pawn push to become passed or have a pawn in front of them.
+ // pawn push to become passed, or have a pawn in front of them.
if ( !pos.pawn_passed(Us, s + Up)
|| (pos.pieces(PAWN) & forward_file_bb(Us, s)))
bonus = bonus / 2;
if (pos.non_pawn_material() < SpaceThreshold)
return SCORE_ZERO;
- // Find the safe squares for our pieces inside the area defined by
- // SpaceMask. A square is unsafe if it is attacked by an enemy
- // pawn, or if it is undefended and attacked by an enemy piece.
+ // Find the available squares for our pieces inside the area defined by SpaceMask
Bitboard safe = SpaceMask
& ~pos.pieces(Us, PAWN)
- & ~attackedBy[Them][PAWN]
- & (attackedBy[Us][ALL_PIECES] | ~attackedBy[Them][ALL_PIECES]);
+ & ~attackedBy[Them][PAWN];
// Find all squares which are at most three squares behind some friendly pawn
Bitboard behind = pos.pieces(Us, PAWN);
Color strongSide = eg > VALUE_DRAW ? WHITE : BLACK;
int sf = me->scale_factor(pos, strongSide);
- // If we don't already have an unusual scale factor, check for certain
- // types of endgames, and use a lower scale for those.
- if (sf == SCALE_FACTOR_NORMAL || sf == SCALE_FACTOR_ONEPAWN)
+ // If scale is not already specific, scale down the endgame via general heuristics
+ if (sf == SCALE_FACTOR_NORMAL)
{
if (pos.opposite_bishops())
{
else
sf = 46;
}
- // Endings where weaker side can place his king in front of the enemy's
- // pawns are drawish.
- else if ( abs(eg) <= BishopValueEg
- && pos.count<PAWN>(strongSide) <= 2
- && !pos.pawn_passed(~strongSide, pos.square<KING>(~strongSide)))
- sf = 37 + 7 * pos.count<PAWN>(strongSide);
+ else
+ sf = std::min(40 + 7 * pos.count<PAWN>(strongSide), sf);
}
return ScaleFactor(sf);
projects / stockfish / blobdiff