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Update to Stockfish 11

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Peter Osterlund
2020-01-18 08:00:03 +01:00
parent c19a3b3777
commit 9c1d76faa1
38 changed files with 1777 additions and 1605 deletions
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519
DroidFishApp/src/main/cpp/stockfish/evaluate.cpp
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@@ -2,7 +2,7 @@
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
Copyright (C) 2015-2020 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
@@ -73,28 +73,17 @@ using namespace Trace;
namespace {
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);
constexpr Bitboard KingFlank[FILE_NB] = {
QueenSide ^ FileDBB, QueenSide, QueenSide,
CenterFiles, CenterFiles,
KingSide, KingSide, KingSide ^ FileEBB
};
// Threshold for lazy and space evaluation
constexpr Value LazyThreshold = Value(1500);
constexpr Value LazyThreshold = Value(1400);
constexpr Value SpaceThreshold = Value(12222);
// KingAttackWeights[PieceType] contains king attack weights by piece type
constexpr int KingAttackWeights[PIECE_TYPE_NB] = { 0, 0, 77, 55, 44, 10 };
constexpr int KingAttackWeights[PIECE_TYPE_NB] = { 0, 0, 81, 52, 44, 10 };
// Penalties for enemy's safe checks
constexpr int QueenSafeCheck = 780;
constexpr int RookSafeCheck = 880;
constexpr int BishopSafeCheck = 435;
constexpr int RookSafeCheck = 1080;
constexpr int BishopSafeCheck = 635;
constexpr int KnightSafeCheck = 790;
#define S(mg, eg) make_score(mg, eg)
@@ -117,61 +106,47 @@ namespace {
S(106,184), S(109,191), S(113,206), S(116,212) }
};
// 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.
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.
constexpr Score RookOnFile[] = { S(18, 7), S(44, 20) };
constexpr Score RookOnFile[] = { S(21, 4), S(47, 25) };
// 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(62, 120)
S(0, 0), S(6, 32), S(59, 41), S(79, 56), S(90, 119), S(79, 161)
};
constexpr Score ThreatByRook[PIECE_TYPE_NB] = {
S(0, 0), S(0, 24), S(38, 71), S(38, 61), S(0, 38), S(51, 38)
S(0, 0), S(3, 44), S(38, 71), S(38, 61), S(0, 38), S(51, 38)
};
// PassedRank[Rank] contains a bonus according to the rank of a passed pawn
constexpr Score PassedRank[RANK_NB] = {
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( -1, 7), S( 0, 9), S(-9, -8), S(-30,-14),
S(-30,-14), S(-9, -8), S( 0, 9), S( -1, 7)
S(0, 0), S(10, 28), S(17, 33), S(15, 41), S(62, 72), S(168, 177), S(276, 260)
};
// Assorted bonuses and penalties
constexpr Score BishopPawns = S( 3, 8);
constexpr Score CloseEnemies = S( 7, 0);
constexpr Score BishopPawns = S( 3, 7);
constexpr Score CorneredBishop = S( 50, 50);
constexpr Score Hanging = S( 62, 34);
constexpr Score KingProtector = S( 6, 7);
constexpr Score KnightOnQueen = S( 20, 12);
constexpr Score LongDiagonalBishop = S( 44, 0);
constexpr Score MinorBehindPawn = S( 16, 0);
constexpr Score Overload = S( 12, 6);
constexpr Score PawnlessFlank = S( 18, 94);
constexpr Score RestrictedPiece = S( 7, 6);
constexpr Score RookOnPawn = S( 10, 28);
constexpr Score SliderOnQueen = S( 49, 21);
constexpr Score ThreatByKing = S( 21, 84);
constexpr Score ThreatByPawnPush = S( 48, 42);
constexpr Score ThreatByRank = S( 14, 3);
constexpr Score ThreatBySafePawn = S(169, 99);
constexpr Score TrappedRook = S( 98, 5);
constexpr Score WeakQueen = S( 51, 10);
constexpr Score WeakUnopposedPawn = S( 14, 20);
constexpr Score FlankAttacks = S( 8, 0);
constexpr Score Hanging = S( 69, 36);
constexpr Score KingProtector = S( 7, 8);
constexpr Score KnightOnQueen = S( 16, 12);
constexpr Score LongDiagonalBishop = S( 45, 0);
constexpr Score MinorBehindPawn = S( 18, 3);
constexpr Score Outpost = S( 30, 21);
constexpr Score PassedFile = S( 11, 8);
constexpr Score PawnlessFlank = S( 17, 95);
constexpr Score RestrictedPiece = S( 7, 7);
constexpr Score ReachableOutpost = S( 32, 10);
constexpr Score RookOnQueenFile = S( 7, 6);
constexpr Score SliderOnQueen = S( 59, 18);
constexpr Score ThreatByKing = S( 24, 89);
constexpr Score ThreatByPawnPush = S( 48, 39);
constexpr Score ThreatBySafePawn = S(173, 94);
constexpr Score TrappedRook = S( 52, 10);
constexpr Score WeakQueen = S( 49, 15);
#undef S
@@ -193,7 +168,7 @@ namespace {
template<Color Us> Score passed() const;
template<Color Us> Score space() const;
ScaleFactor scale_factor(Value eg) const;
Score initiative(Value eg) const;
Score initiative(Score score) const;
const Position& pos;
Material::Entry* me;
@@ -206,15 +181,12 @@ namespace {
// 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,
// possibly via x-ray or by one pawn and one piece. Diagonal x-ray through
// pawn or squares attacked by 2 pawns are not explicitly added.
// attackedBy2[color] are the squares attacked by at least 2 units of a given
// color, including x-rays. But diagonal x-rays through pawns are not computed.
Bitboard attackedBy2[COLOR_NB];
// kingRing[color] are the squares adjacent to the king, plus (only for a
// king on its first rank) the squares two ranks in front. For instance,
// if black's king is on g8, kingRing[BLACK] is f8, h8, f7, g7, h7, f6, g6
// and h6. It is set to 0 when king safety evaluation is skipped.
// kingRing[color] are the squares adjacent to the king plus some other
// very near squares, depending on king position.
Bitboard kingRing[COLOR_NB];
// kingAttackersCount[color] is the number of pieces of the given color
@@ -242,41 +214,37 @@ namespace {
void Evaluation<T>::initialize() {
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);
constexpr Direction Up = pawn_push(Us);
constexpr Direction Down = -Up;
constexpr Bitboard LowRanks = (Us == WHITE ? Rank2BB | Rank3BB : Rank7BB | Rank6BB);
const Square ksq = pos.square<KING>(Us);
Bitboard dblAttackByPawn = pawn_double_attacks_bb<Us>(pos.pieces(Us, PAWN));
// 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 queen, or controlled by enemy pawns
// are excluded from the mobility area.
mobilityArea[Us] = ~(b | pos.pieces(Us, KING, QUEEN) | pe->pawn_attacks(Them));
// Squares occupied by those pawns, by our king or queen, by blockers to attacks on our king
// or controlled by enemy pawns are excluded from the mobility area.
mobilityArea[Us] = ~(b | pos.pieces(Us, KING, QUEEN) | pos.blockers_for_king(Us) | pe->pawn_attacks(Them));
// Initialise attackedBy bitboards for kings and pawns
attackedBy[Us][KING] = pos.attacks_from<KING>(pos.square<KING>(Us));
// Initialize attackedBy[] for king and pawns
attackedBy[Us][KING] = pos.attacks_from<KING>(ksq);
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];
attackedBy2[Us] = dblAttackByPawn | (attackedBy[Us][KING] & attackedBy[Us][PAWN]);
kingRing[Us] = kingAttackersCount[Them] = 0;
// Init our king safety tables
Square s = make_square(clamp(file_of(ksq), FILE_B, FILE_G),
clamp(rank_of(ksq), RANK_2, RANK_7));
kingRing[Us] = PseudoAttacks[KING][s] | s;
// Init our king safety tables only if we are going to use them
if (pos.non_pawn_material(Them) >= RookValueMg + KnightValueMg)
{
kingRing[Us] = attackedBy[Us][KING];
if (relative_rank(Us, pos.square<KING>(Us)) == RANK_1)
kingRing[Us] |= shift<Up>(kingRing[Us]);
kingAttackersCount[Them] = popcount(kingRing[Us] & pe->pawn_attacks(Them));
kingAttacksCount[Them] = kingAttackersWeight[Them] = 0;
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(kingRing[Us] & pe->pawn_attacks(Them));
kingAttacksCount[Them] = kingAttackersWeight[Them] = 0;
}
// Remove from kingRing[] the squares defended by two pawns
kingRing[Us] &= ~dblAttackByPawn;
}
@@ -285,18 +253,17 @@ namespace {
Score Evaluation<T>::pieces() {
constexpr Color Them = (Us == WHITE ? BLACK : WHITE);
constexpr Direction Down = (Us == WHITE ? SOUTH : NORTH);
constexpr Direction Down = -pawn_push(Us);
constexpr Bitboard OutpostRanks = (Us == WHITE ? Rank4BB | Rank5BB | Rank6BB
: Rank5BB | Rank4BB | Rank3BB);
const Square* pl = pos.squares<Pt>(Us);
Bitboard b, bb;
Square s;
Score score = SCORE_ZERO;
attackedBy[Us][Pt] = 0;
while ((s = *pl++) != SQ_NONE)
for (Square s = *pl; s != SQ_NONE; s = *++pl)
{
// Find attacked squares, including x-ray attacks for bishops and rooks
b = Pt == BISHOP ? attacks_bb<BISHOP>(s, pos.pieces() ^ pos.pieces(QUEEN))
@@ -324,12 +291,12 @@ namespace {
if (Pt == BISHOP || Pt == KNIGHT)
{
// Bonus if piece is on an outpost square or can reach one
bb = OutpostRanks & ~pe->pawn_attacks_span(Them);
bb = OutpostRanks & attackedBy[Us][PAWN] & ~pe->pawn_attacks_span(Them);
if (bb & s)
score += Outpost[Pt == BISHOP][bool(attackedBy[Us][PAWN] & s)] * 2;
score += Outpost * (Pt == KNIGHT ? 2 : 1);
else if (bb &= b & ~pos.pieces(Us))
score += Outpost[Pt == BISHOP][bool(attackedBy[Us][PAWN] & bb)];
else if (Pt == KNIGHT && bb & b & ~pos.pieces(Us))
score += ReachableOutpost;
// Knight and Bishop bonus for being right behind a pawn
if (shift<Down>(pos.pieces(PAWN)) & s)
@@ -344,45 +311,44 @@ namespace {
// 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)
score -= BishopPawns * pos.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(attacks_bb<BISHOP>(s, pos.pieces(PAWN)) & Center))
score += LongDiagonalBishop;
}
// An important Chess960 pattern: A cornered bishop blocked by a friendly
// pawn diagonally in front of it is a very serious problem, especially
// when that pawn is also blocked.
if ( Pt == BISHOP
&& pos.is_chess960()
&& (s == relative_square(Us, SQ_A1) || s == relative_square(Us, SQ_H1)))
{
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)) ? CorneredBishop * 4
: pos.piece_on(s + d + d) == make_piece(Us, PAWN) ? CorneredBishop * 2
: CorneredBishop;
// An important Chess960 pattern: a cornered bishop blocked by a friendly
// pawn diagonally in front of it is a very serious problem, especially
// when that pawn is also blocked.
if ( pos.is_chess960()
&& (s == relative_square(Us, SQ_A1) || s == relative_square(Us, SQ_H1)))
{
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)) ? CorneredBishop * 4
: pos.piece_on(s + d + d) == make_piece(Us, PAWN) ? CorneredBishop * 2
: CorneredBishop;
}
}
}
if (Pt == ROOK)
{
// 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]);
// Bonus for rook on the same file as a queen
if (file_bb(s) & pos.pieces(QUEEN))
score += RookOnQueenFile;
// Bonus for rook on an open or semi-open file
if (pe->semiopen_file(Us, file_of(s)))
score += RookOnFile[bool(pe->semiopen_file(Them, file_of(s)))];
if (pos.is_on_semiopen_file(Us, s))
score += RookOnFile[pos.is_on_semiopen_file(Them, s)];
// Penalty when trapped by the king, even more if the king cannot castle
else if (mob <= 3)
{
File kf = file_of(pos.square<KING>(Us));
if ((kf < FILE_E) == (file_of(s) < kf))
score -= (TrappedRook - make_score(mob * 22, 0)) * (1 + !pos.can_castle(Us));
score -= TrappedRook * (1 + !pos.castling_rights(Us));
}
}
@@ -409,89 +375,97 @@ namespace {
constexpr Bitboard Camp = (Us == WHITE ? AllSquares ^ Rank6BB ^ Rank7BB ^ Rank8BB
: AllSquares ^ Rank1BB ^ Rank2BB ^ Rank3BB);
Bitboard weak, b1, b2, b3, safe, unsafeChecks = 0;
Bitboard rookChecks, queenChecks, bishopChecks, knightChecks;
int kingDanger = 0;
const Square ksq = pos.square<KING>(Us);
Bitboard kingFlank, weak, b, b1, b2, safe, unsafeChecks;
// King shelter and enemy pawns storm
// Init the score with king shelter and enemy pawns storm
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;
// Attacked squares defended at most once by our queen or king
weak = attackedBy[Them][ALL_PIECES]
& ~attackedBy2[Us]
& (~attackedBy[Us][ALL_PIECES] | attackedBy[Us][KING] | attackedBy[Us][QUEEN]);
// Analyse the safe enemy's checks which are possible on next move
safe = ~pos.pieces(Them);
safe &= ~attackedBy[Us][ALL_PIECES] | (weak & attackedBy2[Them]);
b1 = attacks_bb<ROOK >(ksq, pos.pieces() ^ pos.pieces(Us, QUEEN));
b2 = attacks_bb<BISHOP>(ksq, pos.pieces() ^ pos.pieces(Us, QUEEN));
// Enemy rooks checks
rookChecks = b1 & safe & attackedBy[Them][ROOK];
if (rookChecks)
kingDanger += RookSafeCheck;
else
unsafeChecks |= b1 & attackedBy[Them][ROOK];
// Enemy queen safe checks: we count them only if they are from squares from
// which we can't give a rook check, because rook checks are more valuable.
queenChecks = (b1 | b2)
& attackedBy[Them][QUEEN]
& safe
& ~attackedBy[Us][QUEEN]
& ~rookChecks;
if (queenChecks)
kingDanger += QueenSafeCheck;
// Enemy bishops checks: we count them only if they are from squares from
// which we can't give a queen check, because queen checks are more valuable.
bishopChecks = b2
& attackedBy[Them][BISHOP]
& safe
& ~queenChecks;
if (bishopChecks)
kingDanger += BishopSafeCheck;
else
unsafeChecks |= b2 & attackedBy[Them][BISHOP];
// Enemy knights checks
knightChecks = pos.attacks_from<KNIGHT>(ksq) & attackedBy[Them][KNIGHT];
if (knightChecks & safe)
kingDanger += KnightSafeCheck;
else
unsafeChecks |= knightChecks;
// Find the squares that opponent attacks in our king flank, the squares
// which they attack twice in that flank, and the squares that we defend.
b1 = attackedBy[Them][ALL_PIECES] & KingFlank[file_of(ksq)] & Camp;
b2 = b1 & attackedBy2[Them];
b3 = attackedBy[Us][ALL_PIECES] & KingFlank[file_of(ksq)] & Camp;
int tropism = popcount(b1) + popcount(b2);
int kingFlankAttack = popcount(b1) + popcount(b2);
int kingFlankDefense = popcount(b3);
// Main king safety evaluation
if (kingAttackersCount[Them] > 1 - pos.count<QUEEN>(Them))
{
int kingDanger = 0;
unsafeChecks = 0;
kingDanger += kingAttackersCount[Them] * kingAttackersWeight[Them]
+ 185 * popcount(kingRing[Us] & weak)
+ 148 * popcount(unsafeChecks)
+ 98 * popcount(pos.blockers_for_king(Us))
+ 69 * kingAttacksCount[Them]
+ 3 * kingFlankAttack * kingFlankAttack / 8
+ mg_value(mobility[Them] - mobility[Us])
- 873 * !pos.count<QUEEN>(Them)
- 100 * bool(attackedBy[Us][KNIGHT] & attackedBy[Us][KING])
- 6 * mg_value(score) / 8
- 4 * kingFlankDefense
+ 37;
// Attacked squares defended at most once by our queen or king
weak = attackedBy[Them][ALL_PIECES]
& ~attackedBy2[Us]
& (~attackedBy[Us][ALL_PIECES] | attackedBy[Us][KING] | attackedBy[Us][QUEEN]);
// Analyse the safe enemy's checks which are possible on next move
safe = ~pos.pieces(Them);
safe &= ~attackedBy[Us][ALL_PIECES] | (weak & attackedBy2[Them]);
b1 = attacks_bb<ROOK >(ksq, pos.pieces() ^ pos.pieces(Us, QUEEN));
b2 = attacks_bb<BISHOP>(ksq, pos.pieces() ^ pos.pieces(Us, QUEEN));
// Enemy queen safe checks
if ((b1 | b2) & attackedBy[Them][QUEEN] & safe & ~attackedBy[Us][QUEEN])
kingDanger += QueenSafeCheck;
b1 &= attackedBy[Them][ROOK];
b2 &= attackedBy[Them][BISHOP];
// Enemy rooks checks
if (b1 & safe)
kingDanger += RookSafeCheck;
else
unsafeChecks |= b1;
// Enemy bishops checks
if (b2 & safe)
kingDanger += BishopSafeCheck;
else
unsafeChecks |= b2;
// Enemy knights checks
b = pos.attacks_from<KNIGHT>(ksq) & attackedBy[Them][KNIGHT];
if (b & safe)
kingDanger += KnightSafeCheck;
else
unsafeChecks |= b;
// Unsafe or occupied checking squares will also be considered, as long as
// the square is in the attacker's mobility area.
unsafeChecks &= mobilityArea[Them];
kingDanger += kingAttackersCount[Them] * kingAttackersWeight[Them]
+ 69 * kingAttacksCount[Them]
+ 185 * popcount(kingRing[Us] & weak)
+ 150 * popcount(pos.blockers_for_king(Us) | unsafeChecks)
+ tropism * tropism / 4
- 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)
score -= make_score(kingDanger * kingDanger / 4096, kingDanger / 16);
}
// Transform the kingDanger units into a Score, and subtract it from the evaluation
if (kingDanger > 100)
score -= make_score(kingDanger * kingDanger / 4096, kingDanger / 16);
// Penalty when our king is on a pawnless flank
if (!(pos.pieces(PAWN) & kingFlank))
if (!(pos.pieces(PAWN) & KingFlank[file_of(ksq)]))
score -= PawnlessFlank;
// King tropism bonus, to anticipate slow motion attacks on our king
score -= CloseEnemies * tropism;
// Penalty if king flank is under attack, potentially moving toward the king
score -= FlankAttacks * kingFlankAttack;
if (T)
Trace::add(KING, Us, score);
@@ -506,14 +480,14 @@ namespace {
Score Evaluation<T>::threats() const {
constexpr Color Them = (Us == WHITE ? BLACK : WHITE);
constexpr Direction Up = (Us == WHITE ? NORTH : SOUTH);
constexpr Direction Up = pawn_push(Us);
constexpr Bitboard TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB);
Bitboard b, weak, defended, nonPawnEnemies, stronglyProtected, safe, restricted;
Bitboard b, weak, defended, nonPawnEnemies, stronglyProtected, safe;
Score score = SCORE_ZERO;
// Non-pawn enemies
nonPawnEnemies = pos.pieces(Them) ^ pos.pieces(Them, PAWN);
nonPawnEnemies = pos.pieces(Them) & ~pos.pieces(PAWN);
// 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.
@@ -526,49 +500,39 @@ namespace {
// 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)
{
b = (defended | weak) & (attackedBy[Us][KNIGHT] | attackedBy[Us][BISHOP]);
while (b)
{
Square s = pop_lsb(&b);
score += ThreatByMinor[type_of(pos.piece_on(s))];
if (type_of(pos.piece_on(s)) != PAWN)
score += ThreatByRank * (int)relative_rank(Them, s);
}
score += ThreatByMinor[type_of(pos.piece_on(pop_lsb(&b)))];
b = weak & attackedBy[Us][ROOK];
while (b)
{
Square s = pop_lsb(&b);
score += ThreatByRook[type_of(pos.piece_on(s))];
if (type_of(pos.piece_on(s)) != PAWN)
score += ThreatByRank * (int)relative_rank(Them, s);
}
score += ThreatByRook[type_of(pos.piece_on(pop_lsb(&b)))];
if (weak & attackedBy[Us][KING])
score += ThreatByKing;
score += Hanging * popcount(weak & ~attackedBy[Them][ALL_PIECES]);
b = weak & nonPawnEnemies & attackedBy[Them][ALL_PIECES];
score += Overload * popcount(b);
b = ~attackedBy[Them][ALL_PIECES]
| (nonPawnEnemies & attackedBy2[Us]);
score += Hanging * popcount(weak & b);
}
// Bonus for restricting their piece moves
restricted = attackedBy[Them][ALL_PIECES]
& ~attackedBy[Them][PAWN]
& ~attackedBy2[Them]
& attackedBy[Us][ALL_PIECES];
score += RestrictedPiece * popcount(restricted);
b = attackedBy[Them][ALL_PIECES]
& ~stronglyProtected
& attackedBy[Us][ALL_PIECES];
// Bonus for enemy unopposed weak pawns
if (pos.pieces(Us, ROOK, QUEEN))
score += WeakUnopposedPawn * pe->weak_unopposed(Them);
score += RestrictedPiece * popcount(b);
// Protected or unattacked squares
safe = ~attackedBy[Them][ALL_PIECES] | attackedBy[Us][ALL_PIECES];
// Bonus for attacking enemy pieces with our relatively safe pawns
b = pos.pieces(Us, PAWN) & safe;
b = pawn_attacks_bb<Us>(b) & nonPawnEnemies;
score += ThreatBySafePawn * popcount(b);
// Find squares where our pawns can push on the next move
b = shift<Up>(pos.pieces(Us, PAWN)) & ~pos.pieces();
@@ -578,14 +542,8 @@ namespace {
b &= ~attackedBy[Them][PAWN] & safe;
// Bonus for safe pawn threats on the next move
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);
score += ThreatByPawnPush * popcount(b);
// Bonus for threats on the next moves against enemy queen
if (pos.count<QUEEN>(Them) == 1)
@@ -616,13 +574,13 @@ namespace {
Score Evaluation<T>::passed() const {
constexpr Color Them = (Us == WHITE ? BLACK : WHITE);
constexpr Direction Up = (Us == WHITE ? NORTH : SOUTH);
constexpr Direction Up = pawn_push(Us);
auto king_proximity = [&](Color c, Square s) {
return std::min(distance(pos.square<KING>(c), s), 5);
};
Bitboard b, bb, squaresToQueen, defendedSquares, unsafeSquares;
Bitboard b, bb, squaresToQueen, unsafeSquares;
Score score = SCORE_ZERO;
b = pe->passed_pawns(Us);
@@ -639,12 +597,12 @@ namespace {
if (r > RANK_3)
{
int w = (r-2) * (r-2) + 2;
int w = 5 * r - 13;
Square blockSq = s + Up;
// Adjust bonus based on the king's proximity
bonus += make_score(0, ( king_proximity(Them, blockSq) * 5
- king_proximity(Us, blockSq) * 2) * w);
bonus += make_score(0, ( (king_proximity(Them, blockSq) * 19) / 4
- king_proximity(Us, blockSq) * 2) * w);
// If blockSq is not the queening square then consider also a second push
if (r != RANK_7)
@@ -653,42 +611,37 @@ namespace {
// If the pawn is free to advance, then increase the bonus
if (pos.empty(blockSq))
{
// If there is a rook or queen attacking/defending the pawn from behind,
// consider all the squaresToQueen. Otherwise consider only the squares
// in the pawn's path attacked or occupied by the enemy.
defendedSquares = unsafeSquares = squaresToQueen = forward_file_bb(Us, s);
squaresToQueen = forward_file_bb(Us, s);
unsafeSquares = passed_pawn_span(Us, s);
bb = forward_file_bb(Them, s) & pos.pieces(ROOK, QUEEN) & pos.attacks_from<ROOK>(s);
if (!(pos.pieces(Us) & bb))
defendedSquares &= attackedBy[Us][ALL_PIECES];
bb = forward_file_bb(Them, s) & pos.pieces(ROOK, QUEEN);
if (!(pos.pieces(Them) & bb))
unsafeSquares &= attackedBy[Them][ALL_PIECES] | pos.pieces(Them);
unsafeSquares &= attackedBy[Them][ALL_PIECES];
// If there aren't any enemy attacks, assign a big bonus. Otherwise
// assign a smaller bonus if the block square isn't attacked.
int k = !unsafeSquares ? 20 : !(unsafeSquares & blockSq) ? 9 : 0;
// If there are no enemy attacks on passed pawn span, assign a big bonus.
// Otherwise assign a smaller bonus if the path to queen is not attacked
// and even smaller bonus if it is attacked but block square is not.
int k = !unsafeSquares ? 35 :
!(unsafeSquares & squaresToQueen) ? 20 :
!(unsafeSquares & blockSq) ? 9 :
0 ;
// If the path to the queen is fully defended, assign a big bonus.
// Otherwise assign a smaller bonus if the block square is defended.
if (defendedSquares == squaresToQueen)
k += 6;
else if (defendedSquares & blockSq)
k += 4;
// Assign a larger bonus if the block square is defended
if ((pos.pieces(Us) & bb) || (attackedBy[Us][ALL_PIECES] & blockSq))
k += 5;
bonus += make_score(k * w, k * w);
}
} // rank > RANK_3
} // r > 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.
if ( !pos.pawn_passed(Us, s + Up)
|| (pos.pieces(PAWN) & forward_file_bb(Us, s)))
|| (pos.pieces(PAWN) & (s + Up)))
bonus = bonus / 2;
score += bonus + PassedFile[file_of(s)];
score += bonus - PassedFile * map_to_queenside(file_of(s));
}
if (T)
@@ -711,7 +664,8 @@ namespace {
if (pos.non_pawn_material() < SpaceThreshold)
return SCORE_ZERO;
constexpr Color Them = (Us == WHITE ? BLACK : WHITE);
constexpr Color Them = (Us == WHITE ? BLACK : WHITE);
constexpr Direction Down = -pawn_push(Us);
constexpr Bitboard SpaceMask =
Us == WHITE ? CenterFiles & (Rank2BB | Rank3BB | Rank4BB)
: CenterFiles & (Rank7BB | Rank6BB | Rank5BB);
@@ -723,12 +677,11 @@ namespace {
// 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);
int bonus = popcount(safe) + popcount(behind & safe);
int weight = pos.count<ALL_PIECES>(Us) - 2 * pe->open_files();
behind |= shift<Down>(behind);
behind |= shift<Down+Down>(behind);
int bonus = popcount(safe) + popcount(behind & safe & ~attackedBy[Them][ALL_PIECES]);
int weight = pos.count<ALL_PIECES>(Us) - 1;
Score score = make_score(bonus * weight * weight / 16, 0);
if (T)
@@ -743,31 +696,44 @@ namespace {
// known attacking/defending status of the players.
template<Tracing T>
Score Evaluation<T>::initiative(Value eg) const {
Score Evaluation<T>::initiative(Score score) const {
Value mg = mg_value(score);
Value eg = eg_value(score);
int outflanking = distance<File>(pos.square<KING>(WHITE), pos.square<KING>(BLACK))
- distance<Rank>(pos.square<KING>(WHITE), pos.square<KING>(BLACK));
bool infiltration = rank_of(pos.square<KING>(WHITE)) > RANK_4
|| rank_of(pos.square<KING>(BLACK)) < RANK_5;
bool pawnsOnBothFlanks = (pos.pieces(PAWN) & QueenSide)
&& (pos.pieces(PAWN) & KingSide);
// Compute the initiative bonus for the attacking side
int complexity = 8 * pe->pawn_asymmetry()
+ 12 * pos.count<PAWN>()
+ 12 * outflanking
+ 16 * pawnsOnBothFlanks
+ 48 * !pos.non_pawn_material()
-118 ;
bool almostUnwinnable = !pe->passed_count()
&& outflanking < 0
&& !pawnsOnBothFlanks;
// 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
// that the endgame score will never change sign after the bonus.
// Compute the initiative bonus for the attacking side
int complexity = 9 * pe->passed_count()
+ 11 * pos.count<PAWN>()
+ 9 * outflanking
+ 12 * infiltration
+ 21 * pawnsOnBothFlanks
+ 51 * !pos.non_pawn_material()
- 43 * almostUnwinnable
- 100 ;
// Now apply the bonus: note that we find the attacking side by extracting the
// sign of the midgame or endgame values, and that we carefully cap the bonus
// so that the midgame and endgame scores do not change sign after the bonus.
int u = ((mg > 0) - (mg < 0)) * std::max(std::min(complexity + 50, 0), -abs(mg));
int v = ((eg > 0) - (eg < 0)) * std::max(complexity, -abs(eg));
if (T)
Trace::add(INITIATIVE, make_score(0, v));
Trace::add(INITIATIVE, make_score(u, v));
return make_score(0, v);
return make_score(u, v);
}
@@ -783,12 +749,12 @@ namespace {
if (sf == SCALE_FACTOR_NORMAL)
{
if ( pos.opposite_bishops()
&& pos.non_pawn_material(WHITE) == BishopValueMg
&& pos.non_pawn_material(BLACK) == BishopValueMg)
sf = 8 + 4 * pe->pawn_asymmetry();
&& pos.non_pawn_material() == 2 * BishopValueMg)
sf = 22 ;
else
sf = std::min(40 + (pos.opposite_bishops() ? 2 : 7) * pos.count<PAWN>(strongSide), sf);
sf = std::min(sf, 36 + (pos.opposite_bishops() ? 2 : 7) * pos.count<PAWN>(strongSide));
sf = std::max(0, sf - (pos.rule50_count() - 12) / 4);
}
return ScaleFactor(sf);
@@ -823,7 +789,7 @@ namespace {
// Early exit if score is high
Value v = (mg_value(score) + eg_value(score)) / 2;
if (abs(v) > LazyThreshold)
if (abs(v) > LazyThreshold + pos.non_pawn_material() / 64)
return pos.side_to_move() == WHITE ? v : -v;
// Main evaluation begins here
@@ -844,14 +810,14 @@ namespace {
+ passed< WHITE>() - passed< BLACK>()
+ space< WHITE>() - space< BLACK>();
score += initiative(eg_value(score));
score += initiative(score);
// Interpolate between a middlegame and a (scaled by 'sf') endgame score
ScaleFactor sf = scale_factor(eg_value(score));
v = mg_value(score) * int(me->game_phase())
+ eg_value(score) * int(PHASE_MIDGAME - me->game_phase()) * sf / SCALE_FACTOR_NORMAL;
v /= int(PHASE_MIDGAME);
v /= PHASE_MIDGAME;
// In case of tracing add all remaining individual evaluation terms
if (T)
@@ -884,6 +850,9 @@ Value Eval::evaluate(const Position& pos) {
std::string Eval::trace(const Position& pos) {
if (pos.checkers())
return "Total evaluation: none (in check)";
std::memset(scores, 0, sizeof(scores));
pos.this_thread()->contempt = SCORE_ZERO; // Reset any dynamic contempt
@@ -899,7 +868,6 @@ std::string Eval::trace(const Position& pos) {
<< " ------------+-------------+-------------+------------\n"
<< " Material | " << Term(MATERIAL)
<< " Imbalance | " << Term(IMBALANCE)
<< " Initiative | " << Term(INITIATIVE)
<< " Pawns | " << Term(PAWN)
<< " Knights | " << Term(KNIGHT)
<< " Bishops | " << Term(BISHOP)
@@ -910,6 +878,7 @@ std::string Eval::trace(const Position& pos) {
<< " Threats | " << Term(THREAT)
<< " Passed | " << Term(PASSED)
<< " Space | " << Term(SPACE)
<< " Initiative | " << Term(INITIATIVE)
<< " ------------+-------------+-------------+------------\n"
<< " Total | " << Term(TOTAL);