#include "evaluate.h"
#include "material.h"
#include "pawns.h"
-
-std::atomic<Score> Eval::Contempt;
+#include "thread.h"
namespace Trace {
namespace {
- 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);
+ constexpr Bitboard QueenSide = FileABB | FileBBB | FileCBB | FileDBB;
+ constexpr Bitboard CenterFiles = FileCBB | FileDBB | FileEBB | FileFBB;
+ constexpr Bitboard KingSide = FileEBB | FileFBB | FileGBB | FileHBB;
+ constexpr Bitboard Center = (FileDBB | FileEBB) & (Rank4BB | Rank5BB);
- const Bitboard KingFlank[FILE_NB] = {
+ constexpr Bitboard KingFlank[FILE_NB] = {
QueenSide, QueenSide, QueenSide,
CenterFiles, CenterFiles,
KingSide, KingSide, KingSide
};
// Threshold for lazy and space evaluation
- const Value LazyThreshold = Value(1500);
- const Value SpaceThreshold = Value(12222);
+ constexpr Value LazyThreshold = Value(1500);
+ constexpr Value SpaceThreshold = Value(12222);
// KingAttackWeights[PieceType] contains king attack weights by piece type
- const int KingAttackWeights[PIECE_TYPE_NB] = { 0, 0, 78, 56, 45, 11 };
+ constexpr int KingAttackWeights[PIECE_TYPE_NB] = { 0, 0, 78, 56, 45, 11 };
// Penalties for enemy's safe checks
- const int QueenSafeCheck = 780;
- const int RookSafeCheck = 880;
- const int BishopSafeCheck = 435;
- const int KnightSafeCheck = 790;
+ constexpr int QueenSafeCheck = 780;
+ constexpr int RookSafeCheck = 880;
+ constexpr int BishopSafeCheck = 435;
+ constexpr int KnightSafeCheck = 790;
#define S(mg, eg) make_score(mg, eg)
// MobilityBonus[PieceType-2][attacked] contains bonuses for middle and end game,
// indexed by piece type and number of attacked squares in the mobility area.
- const Score MobilityBonus[][32] = {
+ 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(-48,-59), S(-20,-23), S( 16, -3), S( 26, 13), S( 38, 24), S( 51, 42), // Bishops
// Outpost[knight/bishop][supported by pawn] contains bonuses for minor
// pieces if they occupy or can reach an outpost square, bigger if that
// square is supported by a pawn.
- const Score Outpost[][2] = {
+ constexpr Score Outpost[][2] = {
{ S(22, 6), S(36,12) }, // Knight
{ S( 9, 2), S(15, 5) } // Bishop
};
// RookOnFile[semiopen/open] contains bonuses for each rook when there is
// no (friendly) pawn on the rook file.
- const Score RookOnFile[] = { S(20, 7), S(45, 20) };
+ constexpr Score RookOnFile[] = { S(20, 7), S(45, 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.
- const Score ThreatByMinor[PIECE_TYPE_NB] = {
+ constexpr Score ThreatByMinor[PIECE_TYPE_NB] = {
S(0, 0), S(0, 31), S(39, 42), S(57, 44), S(68, 112), S(47, 120)
};
- const Score ThreatByRook[PIECE_TYPE_NB] = {
+ constexpr Score ThreatByRook[PIECE_TYPE_NB] = {
S(0, 0), S(0, 24), S(38, 71), S(38, 61), S(0, 38), S(36, 38)
};
// ThreatByKing[on one/on many] contains bonuses for king attacks on
// pawns or pieces which are not pawn-defended.
- const Score ThreatByKing[] = { S(3, 65), S(9, 145) };
+ constexpr Score ThreatByKing[] = { S(3, 65), S(9, 145) };
// PassedRank[Rank] contains a bonus according to the rank of a passed pawn
- const 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)
+ constexpr Score PassedRank[RANK_NB] = {
+ 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
- const 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)
+ constexpr Score PassedFile[FILE_NB] = {
+ 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
- const 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
- const Score KingProtector[] = { S(3, 5), S(4, 3), S(3, 0), S(1, -1) };
+ constexpr Score KingProtector[] = { S(3, 5), S(4, 3), S(3, 0), S(1, -1) };
// Assorted bonuses and penalties
- const Score BishopPawns = S( 8, 12);
- const Score CloseEnemies = S( 7, 0);
- const Score Hanging = S( 52, 30);
- const Score HinderPassedPawn = S( 8, 1);
- 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 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);
- const Score WeakUnopposedPawn = S( 5, 25);
+ 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 Hanging = S( 52, 30);
+ constexpr Score HinderPassedPawn = S( 8, 1);
+ 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);
+ constexpr Score ThreatByPawnPush = S( 47, 26);
+ constexpr Score ThreatByRank = S( 16, 3);
+ constexpr Score ThreatBySafePawn = S(175,168);
+ constexpr Score TrappedRook = S( 92, 0);
+ constexpr Score WeakQueen = S( 50, 10);
+ constexpr Score WeakUnopposedPawn = S( 5, 25);
#undef S
// 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,
// which attack a square in the kingRing of the enemy king.
int kingAttackersCount[COLOR_NB];
- // kingAttackersWeight[color] is the sum of the "weights" of the pieces of the
- // given color which attack a square in the kingRing of the enemy king. The
- // weights of the individual piece types are given by the elements in the
- // KingAttackWeights array.
+ // kingAttackersWeight[color] is the sum of the "weights" of the pieces of
+ // the given color which attack a square in the kingRing of the enemy king.
+ // The weights of the individual piece types are given by the elements in
+ // the KingAttackWeights array.
int kingAttackersWeight[COLOR_NB];
- // kingAdjacentZoneAttacksCount[color] is the number of attacks by the given
- // color to squares directly adjacent to the enemy king. Pieces which attack
- // more than one square are counted multiple times. For instance, if there is
+ // kingAttacksCount[color] is the number of attacks by the given color to
+ // squares directly adjacent to the enemy king. Pieces which attack more
+ // than one square are counted multiple times. For instance, if there is
// a white knight on g5 and black's king is on g8, this white knight adds 2
- // to kingAdjacentZoneAttacksCount[WHITE].
- int kingAdjacentZoneAttacksCount[COLOR_NB];
+ // to kingAttacksCount[WHITE].
+ int kingAttacksCount[COLOR_NB];
};
template<Tracing T> template<Color Us>
void Evaluation<T>::initialize() {
- const Color Them = (Us == WHITE ? BLACK : WHITE);
- const Direction Up = (Us == WHITE ? NORTH : SOUTH);
- const Direction Down = (Us == WHITE ? SOUTH : NORTH);
- const Bitboard LowRanks = (Us == WHITE ? Rank2BB | Rank3BB: Rank7BB | Rank6BB);
+ constexpr Color Them = (Us == WHITE ? BLACK : WHITE);
+ constexpr Direction Up = (Us == WHITE ? NORTH : SOUTH);
+ constexpr Direction Down = (Us == WHITE ? SOUTH : NORTH);
+ constexpr Bitboard LowRanks = (Us == WHITE ? Rank2BB | Rank3BB: Rank7BB | Rank6BB);
// 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));
if (relative_rank(Us, pos.square<KING>(Us)) == RANK_1)
kingRing[Us] |= shift<Up>(kingRing[Us]);
+ if (file_of(pos.square<KING>(Us)) == FILE_H)
+ kingRing[Us] |= shift<WEST>(kingRing[Us]);
+
+ 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));
- kingAdjacentZoneAttacksCount[Them] = kingAttackersWeight[Them] = 0;
+ kingAttacksCount[Them] = kingAttackersWeight[Them] = 0;
}
else
kingRing[Us] = kingAttackersCount[Them] = 0;
template<Tracing T> template<Color Us, PieceType Pt>
Score Evaluation<T>::pieces() {
- const Color Them = (Us == WHITE ? BLACK : WHITE);
- const Bitboard OutpostRanks = (Us == WHITE ? Rank4BB | Rank5BB | Rank6BB
- : Rank5BB | Rank4BB | Rank3BB);
+ 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);
Bitboard b, bb;
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
: Pt == ROOK ? attacks_bb< ROOK>(s, pos.pieces() ^ pos.pieces(QUEEN) ^ pos.pieces(Us, ROOK))
: pos.attacks_from<Pt>(s);
- if (pos.pinned_pieces(Us) & s)
+ if (pos.blockers_for_king(Us) & s)
b &= LineBB[pos.square<KING>(Us)][s];
attackedBy2[Us] |= attackedBy[Us][ALL_PIECES] & b;
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]++;
kingAttackersWeight[Us] += KingAttackWeights[Pt];
- kingAdjacentZoneAttacksCount[Us] += popcount(b & attackedBy[Them][KING]);
+ kingAttacksCount[Us] += popcount(b & attackedBy[Them][KING]);
}
int mob = popcount(b & mobilityArea[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)))
- score += LongRangedBishop;
+ score += LongDiagonalBishop;
}
// An important Chess960 pattern: A cornered bishop blocked by a friendly
{
Direction d = pawn_push(Us) + (file_of(s) == FILE_A ? EAST : WEST);
if (pos.piece_on(s + d) == make_piece(Us, PAWN))
- score -= !pos.empty(s + d + pawn_push(Us)) ? TrappedBishopA1H1 * 4
- : pos.piece_on(s + d + d) == make_piece(Us, PAWN) ? TrappedBishopA1H1 * 2
- : TrappedBishopA1H1;
+ score -= !pos.empty(s + d + pawn_push(Us)) ? CorneredBishop * 4
+ : pos.piece_on(s + d + d) == make_piece(Us, PAWN) ? CorneredBishop * 2
+ : CorneredBishop;
}
}
if (Pt == ROOK)
{
- // Bonus for aligning rook with with enemy pawns on the same rank/file
+ // Bonus for aligning rook with enemy pawns on the same rank/file
if (relative_rank(Us, s) >= RANK_5)
score += RookOnPawn * popcount(pos.pieces(Them, PAWN) & PseudoAttacks[ROOK][s]);
if (Pt == QUEEN)
{
// Penalty if any relative pin or discovered attack against the queen
- Bitboard pinners;
- if (pos.slider_blockers(pos.pieces(Them, ROOK, BISHOP), s, pinners))
+ Bitboard queenPinners;
+ if (pos.slider_blockers(pos.pieces(Them, ROOK, BISHOP), s, queenPinners))
score -= WeakQueen;
}
}
template<Tracing T> template<Color Us>
Score Evaluation<T>::king() const {
- const Color Them = (Us == WHITE ? BLACK : WHITE);
- const Bitboard Camp = (Us == WHITE ? AllSquares ^ Rank6BB ^ Rank7BB ^ Rank8BB
- : AllSquares ^ Rank1BB ^ Rank2BB ^ Rank3BB);
+ constexpr Color Them = (Us == WHITE ? BLACK : WHITE);
+ constexpr Bitboard Camp = (Us == WHITE ? AllSquares ^ Rank6BB ^ Rank7BB ^ Rank8BB
+ : AllSquares ^ Rank1BB ^ Rank2BB ^ Rank3BB);
const Square ksq = pos.square<KING>(Us);
- Bitboard weak, b, b1, b2, safe, unsafeChecks;
+ Bitboard weak, b, b1, b2, safe, unsafeChecks, pinned;
// King shelter and enemy pawns storm
Score score = pe->king_safety<Us>(pos, ksq);
// Main king safety evaluation
if (kingAttackersCount[Them] > 1 - pos.count<QUEEN>(Them))
{
- int kingDanger = unsafeChecks = 0;
+ int kingDanger = 0;
+ unsafeChecks = 0;
// Attacked squares defended at most once by our queen or king
weak = attackedBy[Them][ALL_PIECES]
// 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 * kingAdjacentZoneAttacksCount[Them]
+ + 102 * kingAttacksCount[Them]
+ 191 * popcount(kingRing[Us] & weak)
- + 143 * popcount(pos.pinned_pieces(Us) | unsafeChecks)
+ + 143 * popcount(pinned | unsafeChecks)
- 848 * !pos.count<QUEEN>(Them)
- 9 * mg_value(score) / 8
+ 40;
score -= make_score(kingDanger * kingDanger / 4096, kingDanger / 16);
}
}
- // Penalty when our king is on a pawnless flank
- if (!(pos.pieces(PAWN) & KingFlank[file_of(ksq)]))
- score -= PawnlessFlank;
- // King tropism: firstly, find attacked squares in our king flank
- b = attackedBy[Them][ALL_PIECES] & KingFlank[file_of(ksq)] & Camp;
+ Bitboard kf = KingFlank[file_of(ksq)];
- assert(((Us == WHITE ? b << 4 : b >> 4) & b) == 0);
- assert(popcount(Us == WHITE ? b << 4 : b >> 4) == popcount(b));
+ // Penalty when our king is on a pawnless flank
+ if (!(pos.pieces(PAWN) & kf))
+ score -= PawnlessFlank;
- // 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 & attackedBy2[Them] & ~attackedBy[Us][PAWN]);
+ // 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 -= CloseEnemies * popcount(b);
+ // King tropism, to anticipate slow motion attacks on our king
+ score -= CloseEnemies * (popcount(b1) + popcount(b2));
if (T)
Trace::add(KING, Us, score);
template<Tracing T> template<Color Us>
Score Evaluation<T>::threats() const {
- const Color Them = (Us == WHITE ? BLACK : WHITE);
- const Direction Up = (Us == WHITE ? NORTH : SOUTH);
- const Bitboard TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB);
+ constexpr Color Them = (Us == WHITE ? BLACK : WHITE);
+ constexpr Direction Up = (Us == WHITE ? NORTH : SOUTH);
+ constexpr Bitboard TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB);
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);
- weak = nonPawnEnemies & attackedBy[Us][PAWN];
-
- if (weak)
- {
- // Our safe or protected pawns
- b = pos.pieces(Us, PAWN)
- & (~attackedBy[Them][ALL_PIECES] | attackedBy[Us][ALL_PIECES]);
-
- safeThreats = pawn_attacks_bb<Us>(b) & weak;
- 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.
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();
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 += ThreatOnQueen * popcount(b & safeThreats);
+ score += KnightOnQueen * 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);
template<Tracing T> template<Color Us>
Score Evaluation<T>::passed() const {
- const Color Them = (Us == WHITE ? BLACK : WHITE);
- const Direction Up = (Us == WHITE ? NORTH : SOUTH);
+ constexpr Color Them = (Us == WHITE ? BLACK : WHITE);
+ constexpr Direction Up = (Us == WHITE ? NORTH : SOUTH);
auto king_proximity = [&](Color c, Square s) {
return std::min(distance(pos.square<KING>(c), s), 5);
}
else if (pos.pieces(Us) & blockSq)
bonus += make_score(w + r * 2, w + r * 2);
- } // rr != 0
+ } // 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;
template<Tracing T> template<Color Us>
Score Evaluation<T>::space() const {
- const Color Them = (Us == WHITE ? BLACK : WHITE);
- const Bitboard SpaceMask =
+ 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]
- & (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);
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
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 (ignoring pawns)
- // is almost a draw, in case of KBP vs KB, it is even more a draw.
+ // 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 = more_than_one(pos.pieces(PAWN)) ? 31 : 9;
+ 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);
+ else
+ sf = std::min(40 + 7 * pos.count<PAWN>(strongSide), sf);
}
return ScaleFactor(sf);
// Initialize score by reading the incrementally updated scores included in
// the position object (material + piece square tables) and the material
// imbalance. Score is computed internally from the white point of view.
- Score score = pos.psq_score() + me->imbalance() + Eval::Contempt;
+ Score score = pos.psq_score() + me->imbalance() + pos.this_thread()->contempt;
// Probe the pawn hash table
pe = Pawns::probe(pos);
Trace::add(TOTAL, score);
}
- return pos.side_to_move() == WHITE ? v : -v; // Side to move point of view
+ return (pos.side_to_move() == WHITE ? v : -v) // Side to move point of view
+ + Eval::Tempo;
}
} // namespace
/// evaluation of the position from the point of view of the side to move.
Value Eval::evaluate(const Position& pos) {
- return Evaluation<NO_TRACE>(pos).value() + Eval::Tempo;
+ return Evaluation<NO_TRACE>(pos).value();
}
std::memset(scores, 0, sizeof(scores));
- Eval::Contempt = SCORE_ZERO; // Reset any dynamic contempt
+ pos.this_thread()->contempt = SCORE_ZERO; // Reset any dynamic contempt
- Value v = Evaluation<TRACE>(pos).value() + Eval::Tempo;
+ Value v = Evaluation<TRACE>(pos).value();
v = pos.side_to_move() == WHITE ? v : -v; // Trace scores are from white's point of view
projects / stockfish / blobdiff