#include <iomanip>
#include <sstream>
-#include "bitcount.h"
+#include "bitboard.h"
#include "evaluate.h"
#include "material.h"
#include "pawns.h"
// attacked by a given color and piece type (can be also 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.
+ Bitboard attackedBy2[COLOR_NB];
+
// kingRing[color] is the zone around the king which is considered
// by the king safety evaluation. This consists of the squares directly
// adjacent to the king, and the three (or two, for a king on an edge file)
// 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),
// Outpost[knight/bishop][supported by pawn] contains bonuses for knights and
// bishops outposts, bigger if outpost piece is supported by a pawn.
const Score Outpost[][2] = {
- { S(42,11), S(63,17) }, // Knights
- { S(18, 5), S(27, 8) } // Bishops
+ { S(43,11), S(65,20) }, // Knights
+ { S(20, 3), S(29, 8) } // Bishops
};
// ReachableOutpost[knight/bishop][supported by pawn] contains bonuses for
// knights and bishops which can reach an outpost square in one move, bigger
// if outpost square is supported by a pawn.
const Score ReachableOutpost[][2] = {
- { S(21, 5), S(31, 8) }, // Knights
- { S( 8, 2), S(13, 4) } // Bishops
+ { S(21, 5), S(35, 8) }, // Knights
+ { S( 8, 0), S(14, 4) } // Bishops
};
// RookOnFile[semiopen/open] contains bonuses for each rook when there is no
// friendly pawn on the rook file.
- const Score RookOnFile[2] = { S(19, 10), S(43, 21) };
+ const Score RookOnFile[2] = { S(20, 7), S(45, 20) };
// ThreatBySafePawn[PieceType] contains bonuses according to which piece
// type is attacked by a pawn which is protected or is not attacked.
// Assorted bonuses and penalties used by evaluation
const Score MinorBehindPawn = S(16, 0);
const Score BishopPawns = S( 8, 12);
- const Score RookOnPawn = S( 7, 27);
+ const Score RookOnPawn = S( 8, 24);
const Score TrappedRook = S(92, 0);
- const Score Checked = S(20, 20);
- const Score ThreatByHangingPawn = S(70, 63);
- const Score Hanging = S(48, 28);
- const Score ThreatByPawnPush = S(31, 19);
+ const Score CloseEnemies = S( 7, 0);
+ const Score SafeCheck = S(20, 20);
+ const Score OtherCheck = S(10, 10);
+ const Score ThreatByHangingPawn = S(71, 61);
+ const Score LooseEnemies = S( 0, 25);
+ const Score WeakQueen = S(35, 0);
+ const Score Hanging = S(48, 27);
+ const Score ThreatByPawnPush = S(38, 22);
const Score Unstoppable = S( 0, 20);
// Penalty for a bishop on a1/h1 (a8/h8 for black) which is trapped by
// 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 };
// Penalties for enemy's safe checks
const int QueenContactCheck = 89;
- const int QueenCheck = 50;
- const int RookCheck = 45;
- const int BishopCheck = 6;
- const int KnightCheck = 14;
+ const int QueenCheck = 62;
+ const int RookCheck = 57;
+ const int BishopCheck = 48;
+ const int KnightCheck = 78;
// eval_init() initializes king and attack bitboards for a given color
const Square Down = (Us == WHITE ? DELTA_S : DELTA_N);
ei.pinnedPieces[Us] = pos.pinned_pieces(Us);
- Bitboard b = ei.attackedBy[Them][KING] = pos.attacks_from<KING>(pos.square<KING>(Them));
+ Bitboard b = ei.attackedBy[Them][KING];
ei.attackedBy[Them][ALL_PIECES] |= b;
ei.attackedBy[Us][ALL_PIECES] |= ei.attackedBy[Us][PAWN] = ei.pi->pawn_attacks(Us);
+ ei.attackedBy2[Us] = ei.attackedBy[Us][PAWN] & ei.attackedBy[Us][KING];
// Init king safety tables only if we are going to use them
if (pos.non_pawn_material(Us) >= QueenValueMg)
{
ei.kingRing[Them] = b | shift_bb<Down>(b);
b &= ei.attackedBy[Us][PAWN];
- ei.kingAttackersCount[Us] = b ? popcount<Max15>(b) : 0;
+ ei.kingAttackersCount[Us] = popcount(b);
ei.kingAdjacentZoneAttacksCount[Us] = ei.kingAttackersWeight[Us] = 0;
}
else
if (ei.pinnedPieces[Us] & s)
b &= LineBB[pos.square<KING>(Us)][s];
+ ei.attackedBy2[Us] |= ei.attackedBy[Us][ALL_PIECES] & b;
ei.attackedBy[Us][ALL_PIECES] |= ei.attackedBy[Us][Pt] |= b;
if (b & ei.kingRing[Them])
{
ei.kingAttackersCount[Us]++;
ei.kingAttackersWeight[Us] += KingAttackWeights[Pt];
- bb = b & ei.attackedBy[Them][KING];
- if (bb)
- ei.kingAdjacentZoneAttacksCount[Us] += popcount<Max15>(bb);
+ ei.kingAdjacentZoneAttacksCount[Us] += popcount(b & ei.attackedBy[Them][KING]);
}
if (Pt == QUEEN)
| ei.attackedBy[Them][BISHOP]
| ei.attackedBy[Them][ROOK]);
- int mob = popcount<Pt == QUEEN ? Full : Max15>(b & mobilityArea[Us]);
+ int mob = popcount(b & mobilityArea[Us]);
mobility[Us] += MobilityBonus[Pt][mob];
{
// Bonus for aligning with enemy pawns on the same rank/file
if (relative_rank(Us, s) >= RANK_5)
- {
- Bitboard alignedPawns = pos.pieces(Them, PAWN) & PseudoAttacks[ROOK][s];
- if (alignedPawns)
- score += RookOnPawn * popcount<Max15>(alignedPawns);
- }
+ score += RookOnPawn * popcount(pos.pieces(Them, PAWN) & PseudoAttacks[ROOK][s]);
// Bonus when on an open or semi-open file
if (ei.pi->semiopen_file(Us, file_of(s)))
score -= (TrappedRook - make_score(mob * 22, 0)) * (1 + !pos.can_castle(Us));
}
}
+
+ if (Pt == QUEEN)
+ {
+ // Penalty if any relative pin or discovered attack against the queen
+ if (pos.slider_blockers(pos.pieces(Them, ROOK, BISHOP), s))
+ score -= WeakQueen;
+ }
}
if (DoTrace)
// 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) {
- const Color Them = (Us == WHITE ? BLACK : WHITE);
+ const Color Them = (Us == WHITE ? BLACK : WHITE);
+ const Square Up = (Us == WHITE ? DELTA_N : DELTA_S);
- Bitboard undefended, b, b1, b2, safe;
+ Bitboard undefended, b, b1, b2, safe, other;
int attackUnits;
const Square ksq = pos.square<KING>(Us);
// Main king safety evaluation
if (ei.kingAttackersCount[Them])
{
- // Find the attacked squares around the king which have no defenders
- // apart from the king itself.
- undefended = ei.attackedBy[Them][ALL_PIECES]
- & ei.attackedBy[Us][KING]
- & ~( ei.attackedBy[Us][PAWN] | ei.attackedBy[Us][KNIGHT]
- | ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK]
- | ei.attackedBy[Us][QUEEN]);
+ // Find the attacked squares which are defended only by the king...
+ undefended = ei.attackedBy[Them][ALL_PIECES]
+ & ei.attackedBy[Us][KING]
+ & ~ei.attackedBy2[Us];
+
+ // ... and those which are not defended at all in the larger king ring
+ b = ei.attackedBy[Them][ALL_PIECES] & ~ei.attackedBy[Us][ALL_PIECES]
+ & ei.kingRing[Us] & ~pos.pieces(Them);
// Initialize the 'attackUnits' variable, which is used later on as an
// index into the KingDanger[] array. The initial value is based on the
// the pawn shelter (current 'score' value).
attackUnits = std::min(72, ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them])
+ 9 * ei.kingAdjacentZoneAttacksCount[Them]
- + 27 * popcount<Max15>(undefended)
- + 11 * !!ei.pinnedPieces[Us]
+ + 21 * popcount(undefended)
+ + 12 * (popcount(b) + !!ei.pinnedPieces[Us])
- 64 * !pos.count<QUEEN>(Them)
- mg_value(score) / 8;
// Analyse the enemy's safe queen contact checks. Firstly, find the
// undefended squares around the king reachable by the enemy queen...
b = undefended & ei.attackedBy[Them][QUEEN] & ~pos.pieces(Them);
- if (b)
- {
- // ...and then remove squares not supported by another enemy piece
- b &= ei.attackedBy[Them][PAWN] | ei.attackedBy[Them][KNIGHT]
- | ei.attackedBy[Them][BISHOP] | ei.attackedBy[Them][ROOK]
- | ei.attackedBy[Them][KING];
- if (b)
- attackUnits += QueenContactCheck * popcount<Max15>(b);
- }
+ // ...and keep squares supported by another enemy piece
+ attackUnits += QueenContactCheck * popcount(b & ei.attackedBy2[Them]);
+
+ // Analyse the safe enemy's checks which are possible on next move...
+ safe = ~(ei.attackedBy[Us][ALL_PIECES] | pos.pieces(Them));
- // Analyse the enemy's safe distance checks for sliders and knights
- safe = ~(ei.attackedBy[Us][ALL_PIECES] | pos.pieces(Them));
+ // ... and some other potential checks, only requiring the square to be
+ // safe from pawn-attacks, and not being occupied by a blocked pawn.
+ other = ~( ei.attackedBy[Us][PAWN]
+ | (pos.pieces(Them, PAWN) & shift_bb<Up>(pos.pieces(PAWN))));
- b1 = pos.attacks_from<ROOK >(ksq) & safe;
- b2 = pos.attacks_from<BISHOP>(ksq) & safe;
+ b1 = pos.attacks_from<ROOK >(ksq);
+ b2 = pos.attacks_from<BISHOP>(ksq);
// Enemy queen safe checks
- if ((b1 | b2) & ei.attackedBy[Them][QUEEN])
- attackUnits += QueenCheck, score -= Checked;
+ if ((b1 | b2) & ei.attackedBy[Them][QUEEN] & safe)
+ attackUnits += QueenCheck, score -= SafeCheck;
- // Enemy rooks safe checks
- if (b1 & ei.attackedBy[Them][ROOK])
- attackUnits += RookCheck, score -= Checked;
+ // For other pieces, also consider the square safe if attacked twice,
+ // and only defended by a queen.
+ safe |= ei.attackedBy2[Them]
+ & ~(ei.attackedBy2[Us] | pos.pieces(Them))
+ & ei.attackedBy[Us][QUEEN];
- // Enemy bishops safe checks
- if (b2 & ei.attackedBy[Them][BISHOP])
- attackUnits += BishopCheck, score -= Checked;
+ // Enemy rooks safe and other checks
+ if (b1 & ei.attackedBy[Them][ROOK] & safe)
+ attackUnits += RookCheck, score -= SafeCheck;
- // Enemy knights safe checks
- if (pos.attacks_from<KNIGHT>(ksq) & ei.attackedBy[Them][KNIGHT] & safe)
- attackUnits += KnightCheck, score -= Checked;
+ else if (b1 & ei.attackedBy[Them][ROOK] & other)
+ score -= OtherCheck;
+
+ // Enemy bishops safe and other checks
+ if (b2 & ei.attackedBy[Them][BISHOP] & safe)
+ attackUnits += BishopCheck, score -= SafeCheck;
+
+ else if (b2 & ei.attackedBy[Them][BISHOP] & other)
+ score -= OtherCheck;
+
+ // Enemy knights safe and other checks
+ b = pos.attacks_from<KNIGHT>(ksq) & ei.attackedBy[Them][KNIGHT];
+ if (b & safe)
+ attackUnits += KnightCheck, score -= SafeCheck;
+
+ else if (b & other)
+ score -= OtherCheck;
// Finally, extract the king danger score from the KingDanger[]
// array and subtract the score from the evaluation.
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);
Bitboard b, weak, defended, safeThreats;
Score score = SCORE_ZERO;
+ // Small bonus if the opponent has loose pawns or pieces
+ if ( (pos.pieces(Them) ^ pos.pieces(Them, QUEEN, KING))
+ & ~(ei.attackedBy[Us][ALL_PIECES] | ei.attackedBy[Them][ALL_PIECES]))
+ score += LooseEnemies;
+
// Non-pawn enemies attacked by a pawn
weak = (pos.pieces(Them) ^ pos.pieces(Them, PAWN)) & ei.attackedBy[Us][PAWN];
while (b)
score += Threat[Rook ][type_of(pos.piece_on(pop_lsb(&b)))];
- b = weak & ~ei.attackedBy[Them][ALL_PIECES];
- if (b)
- score += Hanging * popcount<Max15>(b);
+ score += Hanging * popcount(weak & ~ei.attackedBy[Them][ALL_PIECES]);
b = weak & ei.attackedBy[Us][KING];
if (b)
& pos.pieces(Them)
& ~ei.attackedBy[Us][PAWN];
- if (b)
- score += ThreatByPawnPush * popcount<Max15>(b);
+ score += ThreatByPawnPush * popcount(b);
if (DoTrace)
Trace::add(THREAT, Us, score);
Square s = pop_lsb(&b);
assert(pos.pawn_passed(Us, s));
+ assert(!(pos.pieces(PAWN) & forward_bb(Us, s)));
int r = relative_rank(Us, s) - RANK_2;
int rr = r * (r - 1);
mbonus += rr + r * 2, ebonus += rr + r * 2;
} // rr != 0
- if (pos.count<PAWN>(Us) < pos.count<PAWN>(Them))
- ebonus += ebonus / 4;
-
score += make_score(mbonus, ebonus) + PassedFile[file_of(s)];
}
assert(unsigned(safe >> (Us == WHITE ? 32 : 0)) == 0);
// ...count safe + (behind & safe) with a single popcount
- int bonus = popcount<Full>((Us == WHITE ? safe << 32 : safe >> 32) | (behind & safe));
- int weight = pos.count<KNIGHT>(Us) + pos.count<BISHOP>(Us)
- + pos.count<KNIGHT>(Them) + pos.count<BISHOP>(Them);
+ int bonus = popcount((Us == WHITE ? safe << 32 : safe >> 32) | (behind & safe));
+ bonus = std::min(16, bonus);
+ int weight = pos.count<ALL_PIECES>(Us) - 2 * ei.pi->open_files();
- return make_score(bonus * weight * weight * 2 / 11, 0);
+ return make_score(bonus * weight * weight / 18, 0);
}
// 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 = ScaleFactor(46 * sf / SCALE_FACTOR_NORMAL);
+ sf = ScaleFactor(46);
}
// 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;
assert(!pos.checkers());
+ Score mobility[COLOR_NB] = { SCORE_ZERO, SCORE_ZERO };
EvalInfo ei;
- Score score, mobility[COLOR_NB] = { SCORE_ZERO, SCORE_ZERO };
-
- // Initialize score by reading the incrementally updated scores included in
- // the position object (material + piece square tables). Score is computed
- // internally from the white point of view.
- score = pos.psq_score();
// Probe the material hash table
ei.me = Material::probe(pos);
- score += ei.me->imbalance();
// If we have a specialized evaluation function for the current material
// configuration, call it and return.
if (ei.me->specialized_eval_exists())
return ei.me->evaluate(pos);
+ // 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() + ei.me->imbalance();
+
// Probe the pawn hash table
ei.pi = Pawns::probe(pos);
score += ei.pi->pawns_score();
// Initialize attack and king safety bitboards
ei.attackedBy[WHITE][ALL_PIECES] = ei.attackedBy[BLACK][ALL_PIECES] = 0;
+ ei.attackedBy[WHITE][KING] = pos.attacks_from<KING>(pos.square<KING>(WHITE));
+ ei.attackedBy[BLACK][KING] = pos.attacks_from<KING>(pos.square<KING>(BLACK));
eval_init<WHITE>(pos, ei);
eval_init<BLACK>(pos, ei);