constexpr Bitboard Center = (FileDBB | FileEBB) & (Rank4BB | Rank5BB);
constexpr Bitboard KingFlank[FILE_NB] = {
- QueenSide, QueenSide, QueenSide,
+ QueenSide ^ FileDBB, QueenSide, QueenSide,
CenterFiles, CenterFiles,
- KingSide, KingSide, KingSide
+ KingSide, KingSide, KingSide ^ FileEBB
};
// Threshold for lazy and space evaluation
constexpr Value SpaceThreshold = Value(12222);
// KingAttackWeights[PieceType] contains king attack weights by piece type
- constexpr int KingAttackWeights[PIECE_TYPE_NB] = { 0, 0, 78, 56, 45, 11 };
+ constexpr int KingAttackWeights[PIECE_TYPE_NB] = { 0, 0, 77, 55, 44, 10 };
// Penalties for enemy's safe checks
constexpr int QueenSafeCheck = 780;
// MobilityBonus[PieceType-2][attacked] contains bonuses for middle and end game,
// indexed by piece type and number of attacked squares in the mobility area.
constexpr Score MobilityBonus[][32] = {
- { S(-75,-76), S(-57,-54), S( -9,-28), S( -2,-10), S( 6, 5), S( 14, 12), // Knights
- S( 22, 26), S( 29, 29), S( 36, 29) },
+ { S(-62,-81), S(-53,-56), S(-12,-30), S( -4,-14), S( 3, 8), S( 13, 15), // Knights
+ S( 22, 23), S( 28, 27), S( 33, 33) },
{ S(-48,-59), S(-20,-23), S( 16, -3), S( 26, 13), S( 38, 24), S( 51, 42), // Bishops
S( 55, 54), S( 63, 57), S( 63, 65), S( 68, 73), S( 81, 78), S( 81, 86),
S( 91, 88), S( 98, 97) },
// RookOnFile[semiopen/open] contains bonuses for each rook when there is
// no (friendly) pawn on the rook file.
- constexpr Score RookOnFile[] = { S(20, 7), S(45, 20) };
+ constexpr Score RookOnFile[] = { S(18, 7), S(44, 20) };
// ThreatByMinor/ByRook[attacked PieceType] contains bonuses according to
// which piece type attacks which one. Attacks on lesser pieces which are
// pawn-defended are not considered.
constexpr Score ThreatByMinor[PIECE_TYPE_NB] = {
- S(0, 0), S(0, 31), S(39, 42), S(57, 44), S(68, 112), S(47, 120)
+ S(0, 0), S(0, 31), S(39, 42), S(57, 44), S(68, 112), S(62, 120)
};
constexpr Score ThreatByRook[PIECE_TYPE_NB] = {
- S(0, 0), S(0, 24), S(38, 71), S(38, 61), S(0, 38), S(36, 38)
+ S(0, 0), S(0, 24), S(38, 71), S(38, 61), S(0, 38), S(51, 38)
};
- // ThreatByKing[on one/on many] contains bonuses for king attacks on
- // pawns or pieces which are not pawn-defended.
- constexpr Score ThreatByKing[] = { S(3, 65), S(9, 145) };
-
// 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, 18), S(12, 23), S(10, 31), S(57, 62), S(163, 167), S(271, 250)
};
// 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( -1, 7), S( 0, 9), S(-9, -8), S(-30,-14),
+ S(-30,-14), S(-9, -8), S( 0, 9), S( -1, 7)
};
- // PassedDanger[Rank] contains a term to weight the passed score
- constexpr int PassedDanger[RANK_NB] = { 0, 0, 0, 2, 7, 12, 19 };
-
- // 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 CloseEnemies = S( 7, 0);
- constexpr Score Connectivity = S( 3, 1);
+ constexpr Score BishopPawns = S( 3, 7);
+ constexpr Score CloseEnemies = S( 6, 0);
constexpr Score CorneredBishop = S( 50, 50);
- constexpr Score Hanging = S( 52, 30);
- constexpr Score HinderPassedPawn = S( 8, 1);
+ constexpr Score Hanging = S( 57, 32);
+ constexpr Score KingProtector = S( 6, 6);
constexpr Score KnightOnQueen = S( 21, 11);
- constexpr Score LongDiagonalBishop = S( 22, 0);
+ constexpr Score LongDiagonalBishop = S( 46, 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 Overload = S( 13, 6);
+ constexpr Score PawnlessFlank = S( 19, 84);
+ constexpr Score RookOnPawn = S( 10, 29);
constexpr Score SliderOnQueen = S( 42, 21);
- constexpr Score ThreatByPawnPush = S( 47, 26);
+ constexpr Score ThreatByKing = S( 22, 78);
+ constexpr Score ThreatByPawnPush = S( 45, 40);
constexpr Score ThreatByRank = S( 16, 3);
- constexpr Score ThreatBySafePawn = S(175,168);
- constexpr Score TrappedRook = S( 92, 0);
+ constexpr Score ThreatBySafePawn = S(173,102);
+ constexpr Score TrappedRook = S( 96, 5);
constexpr Score WeakQueen = S( 50, 10);
- constexpr Score WeakUnopposedPawn = S( 5, 25);
+ constexpr Score WeakUnopposedPawn = S( 15, 19);
#undef S
attackedBy[Us][PAWN] = pe->pawn_attacks(Us);
attackedBy[Us][ALL_PIECES] = attackedBy[Us][KING] | attackedBy[Us][PAWN];
attackedBy2[Us] = attackedBy[Us][KING] & attackedBy[Us][PAWN];
+ kingRing[Us] = kingAttackersCount[Them] = 0;
// Init our king safety tables only if we are going to use them
if (pos.non_pawn_material(Them) >= RookValueMg + KnightValueMg)
else if (file_of(pos.square<KING>(Us)) == FILE_A)
kingRing[Us] |= shift<EAST>(kingRing[Us]);
- kingAttackersCount[Them] = popcount(attackedBy[Us][KING] & pe->pawn_attacks(Them));
+ kingAttackersCount[Them] = popcount(kingRing[Us] & pe->pawn_attacks(Them));
kingAttacksCount[Them] = kingAttackersWeight[Them] = 0;
}
- else
- kingRing[Us] = kingAttackersCount[Them] = 0;
}
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);
mobility[Us] += MobilityBonus[Pt - 2][mob];
- // Penalty if the piece is far from the king
- score -= KingProtector[Pt - 2] * distance(s, pos.square<KING>(Us));
-
if (Pt == BISHOP || Pt == KNIGHT)
{
// Bonus if piece is on an outpost square or can reach one
else if (bb &= b & ~pos.pieces(Us))
score += Outpost[Pt == BISHOP][bool(attackedBy[Us][PAWN] & bb)];
- // Bonus when behind a pawn
- if ( relative_rank(Us, s) < RANK_5
- && (pos.pieces(PAWN) & (s + pawn_push(Us))))
+ // Knight and Bishop bonus for being right behind a pawn
+ if (shift<Down>(pos.pieces(PAWN)) & s)
score += MinorBehindPawn;
+ // Penalty if the piece is far from the king
+ score -= KingProtector * distance(s, pos.square<KING>(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)))
+ if (more_than_one(attacks_bb<BISHOP>(s, pos.pieces(PAWN)) & Center))
score += LongDiagonalBishop;
}
: AllSquares ^ Rank1BB ^ Rank2BB ^ Rank3BB);
const Square ksq = pos.square<KING>(Us);
- Bitboard weak, b, b1, b2, safe, unsafeChecks, pinned;
+ Bitboard kingFlank, weak, b, b1, b2, safe, unsafeChecks;
// King shelter and enemy pawns storm
- Score score = pe->king_safety<Us>(pos, ksq);
+ Score score = pe->king_safety<Us>(pos);
+
+ // Find the squares that opponent attacks in our king flank, and the squares
+ // which are attacked twice in that flank.
+ kingFlank = KingFlank[file_of(ksq)];
+ b1 = attackedBy[Them][ALL_PIECES] & kingFlank & Camp;
+ b2 = b1 & attackedBy2[Them];
+
+ int tropism = popcount(b1) + popcount(b2);
// Main king safety evaluation
if (kingAttackersCount[Them] > 1 - pos.count<QUEEN>(Them))
// 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)
- - 848 * !pos.count<QUEEN>(Them)
- - 9 * mg_value(score) / 8
- + 40;
+ + 69 * kingAttacksCount[Them]
+ + 185 * popcount(kingRing[Us] & weak)
+ + 150 * popcount(pos.blockers_for_king(Us) | unsafeChecks)
+ + 4 * tropism
+ - 873 * !pos.count<QUEEN>(Them)
+ - 6 * mg_value(score) / 8
+ + mg_value(mobility[Them] - mobility[Us])
+ - 30;
// Transform the kingDanger units into a Score, and subtract it from the evaluation
if (kingDanger > 0)
- {
- int mobilityDanger = mg_value(mobility[Them] - mobility[Us]);
- kingDanger = std::max(0, kingDanger + mobilityDanger);
score -= make_score(kingDanger * kingDanger / 4096, kingDanger / 16);
- }
}
- Bitboard kf = KingFlank[file_of(ksq)];
-
// Penalty when our king is on a pawnless flank
- if (!(pos.pieces(PAWN) & kf))
+ if (!(pos.pieces(PAWN) & kingFlank))
score -= PawnlessFlank;
- // 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];
-
- // King tropism, to anticipate slow motion attacks on our king
- score -= CloseEnemies * (popcount(b1) + popcount(b2));
+ // King tropism bonus, to anticipate slow motion attacks on our king
+ score -= CloseEnemies * tropism;
if (T)
Trace::add(KING, Us, score);
constexpr Direction Up = (Us == WHITE ? NORTH : SOUTH);
constexpr Bitboard TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB);
- Bitboard b, weak, defended, nonPawnEnemies, stronglyProtected, safeThreats;
+ Bitboard b, weak, defended, nonPawnEnemies, stronglyProtected, safe;
Score score = SCORE_ZERO;
// Non-pawn enemies
// Enemies not strongly protected and under our attack
weak = pos.pieces(Them) & ~stronglyProtected & attackedBy[Us][ALL_PIECES];
+ // Safe or protected squares
+ safe = ~attackedBy[Them][ALL_PIECES] | attackedBy[Us][ALL_PIECES];
+
// Bonus according to the kind of attacking pieces
if (defended | weak)
{
score += ThreatByRank * (int)relative_rank(Them, s);
}
- b = (pos.pieces(Them, QUEEN) | weak) & attackedBy[Us][ROOK];
+ b = weak & attackedBy[Us][ROOK];
while (b)
{
Square s = pop_lsb(&b);
score += ThreatByRank * (int)relative_rank(Them, s);
}
- b = weak & attackedBy[Us][KING];
- if (b)
- score += ThreatByKing[more_than_one(b)];
+ if (weak & attackedBy[Us][KING])
+ score += ThreatByKing;
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];
+ b = weak & nonPawnEnemies & attackedBy[Them][ALL_PIECES];
score += Overload * popcount(b);
}
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();
- // Keep only the squares which are not completely unsafe
- b &= ~attackedBy[Them][PAWN]
- & (attackedBy[Us][ALL_PIECES] | ~attackedBy[Them][ALL_PIECES]);
+ // Keep only the squares which are relatively safe
+ b &= ~attackedBy[Them][PAWN] & safe;
// Bonus for safe pawn threats on the next move
- b = pawn_attacks_bb<Us>(b)
- & pos.pieces(Them)
- & ~attackedBy[Us][PAWN];
-
+ b = pawn_attacks_bb<Us>(b) & pos.pieces(Them);
score += ThreatByPawnPush * popcount(b);
+ // Our safe or protected pawns
+ b = pos.pieces(Us, PAWN) & safe;
+
+ b = pawn_attacks_bb<Us>(b) & nonPawnEnemies;
+ score += ThreatBySafePawn * popcount(b);
+
// 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;
+ safe = mobilityArea[Us] & ~stronglyProtected;
b = attackedBy[Us][KNIGHT] & pos.attacks_from<KNIGHT>(s);
- score += KnightOnQueen * popcount(b & safeThreats);
+ score += KnightOnQueen * popcount(b & safe);
b = (attackedBy[Us][BISHOP] & pos.attacks_from<BISHOP>(s))
| (attackedBy[Us][ROOK ] & pos.attacks_from<ROOK >(s));
- score += SliderOnQueen * popcount(b & safeThreats & attackedBy2[Us]);
+ score += SliderOnQueen * popcount(b & safe & 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);
assert(!(pos.pieces(Them, PAWN) & forward_file_bb(Us, s + Up)));
- bb = forward_file_bb(Us, s) & (attackedBy[Them][ALL_PIECES] | pos.pieces(Them));
- score -= HinderPassedPawn * popcount(bb);
-
int r = relative_rank(Us, s);
- int w = PassedDanger[r];
Score bonus = PassedRank[r];
- if (w)
+ if (r > RANK_3)
{
+ int w = (r-2) * (r-2) + 2;
Square blockSq = s + Up;
// Adjust bonus based on the king's proximity
bonus += make_score(k * w, k * w);
}
- else if (pos.pieces(Us) & blockSq)
- bonus += make_score(w + r * 2, w + r * 2);
- } // w != 0
+ } // rank > RANK_3
// 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;
template<Tracing T> template<Color Us>
Score Evaluation<T>::space() const {
+ if (pos.non_pawn_material() < SpaceThreshold)
+ return SCORE_ZERO;
+
constexpr Color Them = (Us == WHITE ? BLACK : WHITE);
constexpr Bitboard SpaceMask =
Us == WHITE ? CenterFiles & (Rank2BB | Rank3BB | Rank4BB)
: CenterFiles & (Rank7BB | Rank6BB | Rank5BB);
- 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];
&& (pos.pieces(PAWN) & KingSide);
// Compute the initiative bonus for the attacking side
- int complexity = 8 * outflanking
- + 8 * pe->pawn_asymmetry()
+ int complexity = 8 * pe->pawn_asymmetry()
+ 12 * pos.count<PAWN>()
+ + 12 * outflanking
+ 16 * pawnsOnBothFlanks
+ 48 * !pos.non_pawn_material()
- -136 ;
+ -118 ;
// Now apply the bonus: note that we find the attacking side by extracting
// the sign of the endgame value, and that we carefully cap the bonus so
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())
- {
- // Endgame with opposite-colored bishops and no other pieces is almost a draw
- if ( pos.non_pawn_material(WHITE) == BishopValueMg
- && pos.non_pawn_material(BLACK) == BishopValueMg)
- sf = 31;
-
- // Endgame with opposite-colored bishops, but also other pieces. Still
- // a bit drawish, but not as drawish as with only the two 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);
+ if ( pos.opposite_bishops()
+ && pos.non_pawn_material(WHITE) == BishopValueMg
+ && pos.non_pawn_material(BLACK) == BishopValueMg)
+ sf = 8 + 4 * pe->pawn_asymmetry();
+ else
+ sf = std::min(40 + (pos.opposite_bishops() ? 2 : 7) * pos.count<PAWN>(strongSide), sf);
+
}
return ScaleFactor(sf);
projects / stockfish / blobdiff