Material::Entry* me;
Pawns::Entry* pe;
- Bitboard pinnedPieces[COLOR_NB];
Bitboard mobilityArea[COLOR_NB];
// attackedBy[color][piece type] is a bitboard representing all squares
#define V(v) Value(v)
#define S(mg, eg) make_score(mg, eg)
- // MobilityBonus[PieceType][attacked] contains bonuses for middle and end game,
+ // 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] = {
- {}, {},
- { 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),
- S( 92, 90), S( 97, 94) },
- { S(-56,-78), S(-25,-18), S(-11, 26), S( -5, 55), S( -4, 70), S( -1, 81), // Rooks
- S( 8,109), S( 14,120), S( 21,128), S( 23,143), S( 31,154), S( 32,160),
- S( 43,165), S( 49,168), S( 59,169) },
- { S(-40,-35), S(-25,-12), S( 2, 7), S( 4, 19), S( 14, 37), S( 24, 55), // Queens
- S( 25, 62), S( 40, 76), S( 43, 79), S( 47, 87), S( 54, 94), S( 56,102),
- S( 60,111), S( 70,116), S( 72,118), S( 73,122), S( 75,128), S( 77,130),
- S( 85,133), S( 94,136), S( 99,140), S(108,157), S(112,158), S(113,161),
- S(118,174), S(119,177), S(123,191), S(128,199) }
+ const Score MobilityBonus[4][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
+ S( 55, 54), S( 63, 57), S( 63, 65), S( 68, 73), S( 81, 78), S( 81, 86),
+ S( 91, 88), S( 98, 97) },
+ { S(-60,-77), S(-26,-20), S(-11, 27), S( -6, 57), S( -3, 69), S( -1, 82), // Rooks
+ S( 10,109), S( 16,121), S( 24,131), S( 25,143), S( 32,155), S( 32,163),
+ S( 43,167), S( 48,171), S( 56,173) },
+ { S(-39,-36), S(-21,-15), S( 3, 8), S( 3, 18), S( 14, 34), S( 22, 54), // Queens
+ S( 28, 61), S( 41, 73), S( 43, 79), S( 48, 92), S( 56, 94), S( 60,104),
+ S( 60,113), S( 66,120), S( 67,123), S( 70,126), S( 71,133), S( 73,136),
+ S( 79,140), S( 88,143), S( 88,148), S( 99,166), S(102,170), S(102,175),
+ S(106,184), S(109,191), S(113,206), S(116,212) }
};
// Outpost[knight/bishop][supported by pawn] contains bonuses for minor
S( 9, 10), S( 2, 10), S( 1, -8), S(-20,-12),
S(-20,-12), S( 1, -8), S( 2, 10), S( 9, 10)
};
+
+ // Protector[PieceType-2][distance] contains a protecting bonus for our king,
+ // indexed by piece type and distance between the piece and the king.
+ const Score Protector[4][8] = {
+ { S(0, 0), S( 7, 9), S( 7, 1), S( 1, 5), S(-10,-4), S( -1,-4), S( -7,-3), S(-16,-10) }, // Knight
+ { S(0, 0), S(11, 8), S(-7,-1), S(-1,-2), S( -1,-7), S(-11,-3), S( -9,-1), S(-16, -1) }, // Bishop
+ { S(0, 0), S(10, 0), S(-2, 2), S(-5, 4), S( -6, 2), S(-14,-3), S( -2,-9), S(-12, -7) }, // Rook
+ { S(0, 0), S( 3,-5), S( 2,-5), S(-4, 0), S( -9,-6), S(-4, 7), S(-13,-7), S(-10, -7) } // Queen
+ };
// Assorted bonuses and penalties used by evaluation
const Score MinorBehindPawn = S(16, 0);
const Score OtherCheck = S(10, 10);
const Score CloseEnemies = S( 7, 0);
const Score PawnlessFlank = S(20, 80);
- const Score LooseEnemies = S( 0, 25);
const Score ThreatByHangingPawn = S(71, 61);
const Score ThreatByRank = S(16, 3);
const Score Hanging = S(48, 27);
const int KingAttackWeights[PIECE_TYPE_NB] = { 0, 0, 78, 56, 45, 11 };
// Penalties for enemy's safe checks
- const int QueenContactCheck = 997;
const int QueenCheck = 745;
const int RookCheck = 688;
const int BishopCheck = 588;
const int KnightCheck = 924;
// Threshold for lazy evaluation
- const Value LazyEval = Value(1500);
+ const Value LazyThreshold = Value(1500);
// eval_init() initializes king and attack bitboards for a given color
// adding pawn attacks. To be done at the beginning of the evaluation.
const Square Down = (Us == WHITE ? SOUTH : NORTH);
const Bitboard LowRanks = (Us == WHITE ? Rank2BB | Rank3BB: Rank7BB | Rank6BB);
- ei.pinnedPieces[Us] = pos.pinned_pieces(Us);
-
// Find our pawns on the first two ranks, and those which are blocked
Bitboard b = pos.pieces(Us, PAWN) & (shift<Down>(pos.pieces()) | LowRanks);
: Pt == ROOK ? attacks_bb< ROOK>(s, pos.pieces() ^ pos.pieces(Us, ROOK, QUEEN))
: pos.attacks_from<Pt>(s);
- if (ei.pinnedPieces[Us] & s)
+ if (pos.pinned_pieces(Us) & s)
b &= LineBB[pos.square<KING>(Us)][s];
ei.attackedBy2[Us] |= ei.attackedBy[Us][ALL_PIECES] & b;
ei.kingAdjacentZoneAttacksCount[Us] += popcount(b & ei.attackedBy[Them][KING]);
}
- if (Pt == QUEEN)
- b &= ~( ei.attackedBy[Them][KNIGHT]
- | ei.attackedBy[Them][BISHOP]
- | ei.attackedBy[Them][ROOK]);
-
int mob = popcount(b & ei.mobilityArea[Us]);
- mobility[Us] += MobilityBonus[Pt][mob];
+ mobility[Us] += MobilityBonus[Pt-2][mob];
+
+ // Bonus for this piece as a king protector
+ score += Protector[Pt-2][distance(s, pos.square<KING>(Us))];
if (Pt == BISHOP || Pt == KNIGHT)
{
// evaluate_king() assigns bonuses and penalties to a king of a given color
+ const Bitboard QueenSide = FileABB | FileBBB | FileCBB | FileDBB;
const Bitboard CenterFiles = FileCBB | FileDBB | FileEBB | FileFBB;
+ const Bitboard KingSide = FileEBB | FileFBB | FileGBB | FileHBB;
const Bitboard KingFlank[FILE_NB] = {
- CenterFiles >> 2, CenterFiles >> 2, CenterFiles >> 2, CenterFiles, CenterFiles,
- CenterFiles << 2, CenterFiles << 2, CenterFiles << 2
+ QueenSide, QueenSide, QueenSide, CenterFiles, CenterFiles, KingSide, KingSide, KingSide
};
template<Color Us, bool DoTrace>
kingDanger = std::min(807, ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them])
+ 101 * ei.kingAdjacentZoneAttacksCount[Them]
+ 235 * popcount(undefended)
- + 134 * (popcount(b) + !!ei.pinnedPieces[Us])
+ + 134 * (popcount(b) + !!pos.pinned_pieces(Us))
- 717 * !pos.count<QUEEN>(Them)
- 7 * mg_value(score) / 5 - 5;
- // Analyse the enemy's safe queen contact checks. Firstly, find the
- // undefended squares around our king reachable by the enemy queen...
- b = undefended & ei.attackedBy[Them][QUEEN] & ~pos.pieces(Them);
-
- // ...and keep squares supported by another enemy piece.
- kingDanger += 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));
+ safe = ~pos.pieces(Them);
+ safe &= ~ei.attackedBy[Us][ALL_PIECES] | (undefended & ei.attackedBy2[Them]);
b1 = pos.attacks_from<ROOK >(ksq);
b2 = pos.attacks_from<BISHOP>(ksq);
const Bitboard TRank2BB = (Us == WHITE ? Rank2BB : Rank7BB);
const Bitboard TRank7BB = (Us == WHITE ? Rank7BB : Rank2BB);
- Bitboard b, weak, defended, safeThreats;
+ Bitboard b, weak, defended, stronglyProtected, 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];
score += ThreatBySafePawn[type_of(pos.piece_on(pop_lsb(&safeThreats)))];
}
- // Non-pawn enemies defended by a pawn
- defended = (pos.pieces(Them) ^ pos.pieces(Them, PAWN)) & ei.attackedBy[Them][PAWN];
+ // Squares strongly protected by the opponent, either because they attack the
+ // square with a pawn, or because they attack the square twice and we don't.
+ stronglyProtected = ei.attackedBy[Them][PAWN]
+ | (ei.attackedBy2[Them] & ~ei.attackedBy2[Us]);
+
+ // Non-pawn enemies, strongly protected
+ defended = (pos.pieces(Them) ^ pos.pieces(Them, PAWN))
+ & stronglyProtected;
- // Enemies not defended by a pawn and under our attack
+ // Enemies not strongly protected and under our attack
weak = pos.pieces(Them)
- & ~ei.attackedBy[Them][PAWN]
+ & ~stronglyProtected
& ei.attackedBy[Us][ALL_PIECES];
// Add a bonus according to the kind of attacking pieces
}
- // evaluate_passed_pawns() evaluates the passed pawns of the given color
+ // evaluate_passer_pawns() evaluates the passed pawns and candidate passed
+ // pawns of the given color.
template<Color Us, bool DoTrace>
- Score evaluate_passed_pawns(const Position& pos, const EvalInfo& ei) {
+ Score evaluate_passer_pawns(const Position& pos, const EvalInfo& ei) {
const Color Them = (Us == WHITE ? BLACK : WHITE);
{
Square s = pop_lsb(&b);
- assert(pos.pawn_passed(Us, s));
assert(!(pos.pieces(PAWN) & forward_bb(Us, s)));
bb = forward_bb(Us, s) & (ei.attackedBy[Them][ALL_PIECES] | pos.pieces(Them));
mbonus += rr + r * 2, ebonus += rr + r * 2;
} // rr != 0
- // Assign a small bonus when the opponent has no pieces left
- if (!pos.non_pawn_material(Them))
- ebonus += 20;
+ // Scale down bonus for candidate passers which need more than one
+ // pawn push to become passed.
+ if (!pos.pawn_passed(Us, s + pawn_push(Us)))
+ mbonus /= 2, ebonus /= 2;
score += make_score(mbonus, ebonus) + PassedFile[file_of(s)];
}
if (DoTrace)
Trace::add(PASSED, Us, score);
- // Add the scores to the middlegame and endgame eval
return score;
}
int kingDistance = distance<File>(pos.square<KING>(WHITE), pos.square<KING>(BLACK))
- distance<Rank>(pos.square<KING>(WHITE), pos.square<KING>(BLACK));
int pawns = pos.count<PAWN>(WHITE) + pos.count<PAWN>(BLACK);
+ bool bothFlanks = (pos.pieces(PAWN) & QueenSide) && (pos.pieces(PAWN) & KingSide);
// Compute the initiative bonus for the attacking side
- int initiative = 8 * (asymmetry + kingDistance - 15) + 12 * pawns;
+ int initiative = 8 * (asymmetry + kingDistance - 17) + 12 * pawns + 16 * bothFlanks;
// 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 be divided by more than two.
- int value = ((eg > 0) - (eg < 0)) * std::max(initiative, -abs(eg / 2));
+ // that the endgame score will never change sign after the bonus.
+ int value = ((eg > 0) - (eg < 0)) * std::max(initiative, -abs(eg));
return make_score(0, value);
}
// If we don't already have an unusual scale factor, check for certain
// types of endgames, and use a lower scale for those.
- if ( ei.me->game_phase() < PHASE_MIDGAME
- && (sf == SCALE_FACTOR_NORMAL || sf == SCALE_FACTOR_ONEPAWN))
+ if (sf == SCALE_FACTOR_NORMAL || sf == SCALE_FACTOR_ONEPAWN)
{
if (pos.opposite_bishops())
{
// is almost a draw, in case of KBP vs KB, it is even more a draw.
if ( pos.non_pawn_material(WHITE) == BishopValueMg
&& pos.non_pawn_material(BLACK) == BishopValueMg)
- sf = more_than_one(pos.pieces(PAWN)) ? ScaleFactor(31) : ScaleFactor(9);
+ return more_than_one(pos.pieces(PAWN)) ? ScaleFactor(31) : ScaleFactor(9);
// 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);
+ return ScaleFactor(46);
}
// Endings where weaker side can place his king in front of the opponent's
// pawns are drawish.
else if ( abs(eg) <= BishopValueEg
&& pos.count<PAWN>(strongSide) <= 2
&& !pos.pawn_passed(~strongSide, pos.square<KING>(~strongSide)))
-
sf = ScaleFactor(37 + 7 * pos.count<PAWN>(strongSide));
+
return ScaleFactor(37 + 7 * pos.count<PAWN>(strongSide));
}
return sf;
}
-
- Value lazy_eval(Value mg, Value eg) {
-
- if (mg > LazyEval && eg > LazyEval)
- return LazyEval + ((mg + eg) / 2 - LazyEval) / 4;
-
- else if (mg < -LazyEval && eg < -LazyEval)
- return -LazyEval + ((mg + eg) / 2 + LazyEval) / 4;
-
- return VALUE_ZERO;
- }
-
} // namespace
assert(!pos.checkers());
Score mobility[COLOR_NB] = { SCORE_ZERO, SCORE_ZERO };
+ Value v;
EvalInfo ei;
// Probe the material hash table
ei.pe = Pawns::probe(pos);
score += ei.pe->pawns_score();
- // We have taken into account all cheap evaluation terms.
- // If score exceeds a threshold return a lazy evaluation.
- Value lazy = lazy_eval(mg_value(score), eg_value(score));
- if (lazy)
- return pos.side_to_move() == WHITE ? lazy : -lazy;
+ // Early exit if score is high
+ v = (mg_value(score) + eg_value(score)) / 2;
+ if (abs(v) > LazyThreshold)
+ return pos.side_to_move() == WHITE ? v : -v;
// Initialize attack and king safety bitboards
eval_init<WHITE>(pos, ei);
- evaluate_threats<BLACK, DoTrace>(pos, ei);
// Evaluate passed pawns, we need full attack information including king
- score += evaluate_passed_pawns<WHITE, DoTrace>(pos, ei)
- - evaluate_passed_pawns<BLACK, DoTrace>(pos, ei);
+ score += evaluate_passer_pawns<WHITE, DoTrace>(pos, ei)
+ - evaluate_passer_pawns<BLACK, DoTrace>(pos, ei);
// Evaluate space for both sides, only during opening
if (pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) >= 12222)
ScaleFactor sf = evaluate_scale_factor(pos, ei, eg_value(score));
// Interpolate between a middlegame and a (scaled by 'sf') endgame score
- Value v = mg_value(score) * int(ei.me->game_phase())
- + eg_value(score) * int(PHASE_MIDGAME - ei.me->game_phase()) * sf / SCALE_FACTOR_NORMAL;
+ v = mg_value(score) * int(ei.me->game_phase())
+ + eg_value(score) * int(PHASE_MIDGAME - ei.me->game_phase()) * sf / SCALE_FACTOR_NORMAL;
v /= int(PHASE_MIDGAME);
projects / stockfish / blobdiff