// 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)
+ // adjacent to the king, and (only for a king on its first rank) the
// squares two ranks in front of the king. For instance, if black's king
// is on g8, kingRing[BLACK] is a bitboard containing the squares f8, h8,
// f7, g7, h7, f6, g6 and h6.
// 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[4][32] = {
+ const 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
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(-58,-76), S(-27,-18), S(-15, 28), S(-10, 55), S( -5, 69), S( -2, 82), // Rooks
+ S( 9,112), S( 16,118), S( 30,132), S( 29,142), S( 32,155), S( 38,165),
+ S( 46,166), S( 48,169), S( 58,171) },
{ 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),
// RookOnFile[semiopen/open] contains bonuses for each rook when there is no
// friendly pawn on the rook file.
- 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.
- const Score ThreatBySafePawn[PIECE_TYPE_NB] = {
- S(0, 0), S(0, 0), S(176, 139), S(131, 127), S(217, 218), S(203, 215)
- };
+ const 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
};
const Score ThreatByRook[PIECE_TYPE_NB] = {
- S(0, 0), S(0, 25), S(40, 62), S(40, 59), S( 0, 34), S(35, 48)
+ S(0, 0), S(0, 25), S(40, 62), S(40, 59), S(0, 34), S(35, 48)
};
// ThreatByKing[on one/on many] contains bonuses for king attacks on
// pawns or pieces which are not pawn-defended.
- const Score ThreatByKing[2] = { S(3, 62), S(9, 138) };
+ const Score ThreatByKing[] = { S(3, 62), S(9, 138) };
// Passed[mg/eg][Rank] contains midgame and endgame bonuses for passed pawns.
// We don't use a Score because we process the two components independently.
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
- };
+ // KingProtector[PieceType-2] contains a bonus according to distance from king
+ const Score KingProtector[] = { S(-3, -5), S(-4, -3), S(-3, 0), S(-1, 1) };
// Assorted bonuses and penalties used by evaluation
- const Score MinorBehindPawn = S(16, 0);
- const Score BishopPawns = S( 8, 12);
- const Score RookOnPawn = S( 8, 24);
- const Score TrappedRook = S(92, 0);
- const Score WeakQueen = S(50, 10);
- const Score OtherCheck = S(10, 10);
- const Score CloseEnemies = S( 7, 0);
- const Score PawnlessFlank = S(20, 80);
- const Score ThreatByHangingPawn = S(71, 61);
- const Score ThreatByRank = S(16, 3);
- const Score Hanging = S(48, 27);
- const Score ThreatByPawnPush = S(38, 22);
- const Score HinderPassedPawn = S( 7, 0);
+ const Score MinorBehindPawn = S( 16, 0);
+ const Score BishopPawns = S( 8, 12);
+ const Score RookOnPawn = S( 8, 24);
+ const Score TrappedRook = S( 92, 0);
+ const Score WeakQueen = S( 50, 10);
+ const Score OtherCheck = S( 10, 10);
+ const Score CloseEnemies = S( 7, 0);
+ const Score PawnlessFlank = S( 20, 80);
+ const Score ThreatByHangingPawn = S( 71, 61);
+ const Score ThreatBySafePawn = S(182,175);
+ const Score ThreatByRank = S( 16, 3);
+ const Score Hanging = S( 48, 27);
+ const Score ThreatByPawnPush = S( 38, 22);
+ const Score HinderPassedPawn = S( 7, 0);
// Penalty for a bishop on a1/h1 (a8/h8 for black) which is trapped by
// a friendly pawn on b2/g2 (b7/g7 for black). This can obviously only
const int KingAttackWeights[PIECE_TYPE_NB] = { 0, 0, 78, 56, 45, 11 };
// Penalties for enemy's safe checks
- const int QueenCheck = 745;
- const int RookCheck = 688;
- const int BishopCheck = 588;
- const int KnightCheck = 924;
+ const int QueenCheck = 780;
+ const int RookCheck = 880;
+ const int BishopCheck = 435;
+ const int KnightCheck = 790;
- // Threshold for lazy evaluation
- const Value LazyThreshold = Value(1500);
+ // Threshold for lazy and space evaluation
+ const Value LazyThreshold = Value(1500);
+ const Value SpaceThreshold = Value(12222);
// eval_init() initializes king and attack bitboards for a given color
// adding pawn attacks. To be done at the beginning of the evaluation.
ei.attackedBy[Us][ALL_PIECES] = b | ei.attackedBy[Us][PAWN];
// Init our king safety tables only if we are going to use them
- if (pos.non_pawn_material(Them) >= QueenValueMg)
+ if (pos.non_pawn_material(Them) >= RookValueMg + KnightValueMg)
{
- ei.kingRing[Us] = b | shift<Up>(b);
+ ei.kingRing[Us] = b;
+ if (relative_rank(Us, pos.square<KING>(Us)) == RANK_1)
+ ei.kingRing[Us] |= shift<Up>(b);
+
ei.kingAttackersCount[Them] = popcount(b & ei.pe->pawn_attacks(Them));
ei.kingAdjacentZoneAttacksCount[Them] = ei.kingAttackersWeight[Them] = 0;
}
template<bool DoTrace, Color Us = WHITE, PieceType Pt = KNIGHT>
Score evaluate_pieces(const Position& pos, EvalInfo& ei, Score* mobility) {
- const PieceType NextPt = (Us == WHITE ? Pt : PieceType(Pt + 1));
const Color Them = (Us == WHITE ? BLACK : WHITE);
+ const PieceType NextPt = (Us == WHITE ? Pt : PieceType(Pt + 1));
const Bitboard OutpostRanks = (Us == WHITE ? Rank4BB | Rank5BB | Rank6BB
: Rank5BB | Rank4BB | Rank3BB);
const Square* pl = pos.squares<Pt>(Us);
int mob = popcount(b & ei.mobilityArea[Us]);
- mobility[Us] += MobilityBonus[Pt-2][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))];
+ score += KingProtector[Pt - 2] * distance(s, pos.square<KING>(Us));
if (Pt == BISHOP || Pt == KNIGHT)
{
Score score = ei.pe->king_safety<Us>(pos, ksq);
// Main king safety evaluation
- if (ei.kingAttackersCount[Them])
+ if (ei.kingAttackersCount[Them] > (1 - pos.count<QUEEN>(Them)))
{
// Find the attacked squares which are defended only by our king...
undefended = ei.attackedBy[Them][ALL_PIECES]
// number and types of the enemy's attacking pieces, the number of
// attacked and undefended squares around our king and the quality of
// the pawn shelter (current 'score' value).
- kingDanger = std::min(807, ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them])
- + 101 * ei.kingAdjacentZoneAttacksCount[Them]
- + 235 * popcount(undefended)
- + 134 * (popcount(b) + !!pos.pinned_pieces(Us))
- - 717 * !pos.count<QUEEN>(Them)
- - 7 * mg_value(score) / 5 - 5;
+ kingDanger = ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]
+ + 102 * ei.kingAdjacentZoneAttacksCount[Them]
+ + 201 * popcount(undefended)
+ + 143 * (popcount(b) + !!pos.pinned_pieces(Us))
+ - 848 * !pos.count<QUEEN>(Them)
+ - 9 * mg_value(score) / 8
+ + 40;
// Analyse the safe enemy's checks which are possible on next move
safe = ~pos.pieces(Them);
safe &= ~ei.attackedBy[Us][ALL_PIECES] | (undefended & ei.attackedBy2[Them]);
- b1 = pos.attacks_from<ROOK >(ksq);
+ b1 = pos.attacks_from< ROOK>(ksq);
b2 = pos.attacks_from<BISHOP>(ksq);
// Enemy queen safe checks
// Transform the kingDanger units into a Score, and substract it from the evaluation
if (kingDanger > 0)
- score -= make_score(std::min(kingDanger * kingDanger / 4096, 2 * int(BishopValueMg)), 0);
+ score -= make_score(kingDanger * kingDanger / 4096, kingDanger / 16);
}
// King tropism: firstly, find squares that opponent attacks in our king flank
safeThreats = (shift<Right>(b) | shift<Left>(b)) & weak;
+ score += ThreatBySafePawn * popcount(safeThreats);
+
if (weak ^ safeThreats)
score += ThreatByHangingPawn;
-
- while (safeThreats)
- score += ThreatBySafePawn[type_of(pos.piece_on(pop_lsb(&safeThreats)))];
}
// Squares strongly protected by the opponent, either because they attack the
{
Square s = pop_lsb(&b);
- assert(!(pos.pieces(PAWN) & forward_bb(Us, s)));
+ assert(!(pos.pieces(Them, PAWN) & forward_bb(Us, s + pawn_push(Us))));
bb = forward_bb(Us, s) & (ei.attackedBy[Them][ALL_PIECES] | pos.pieces(Them));
score -= HinderPassedPawn * popcount(bb);
// Adjust bonus based on the king's proximity
ebonus += distance(pos.square<KING>(Them), blockSq) * 5 * rr
- - distance(pos.square<KING>(Us ), blockSq) * 2 * rr;
+ - distance(pos.square<KING>( Us), blockSq) * 2 * rr;
// If blockSq is not the queening square then consider also a second push
if (relative_rank(Us, blockSq) != RANK_8)
} // rr != 0
// 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)))
+ // pawn push to become passed or have a pawn in front of them.
+ if (!pos.pawn_passed(Us, s + pawn_push(Us)) || (pos.pieces(PAWN) & forward_bb(Us, s)))
mbonus /= 2, ebonus /= 2;
score += make_score(mbonus, ebonus) + PassedFile[file_of(s)];
// ...count safe + (behind & safe) with a single popcount.
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.pe->open_files();
- return make_score(bonus * weight * weight / 18, 0);
+ return make_score(bonus * weight * weight / 16, 0);
}
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>();
bool bothFlanks = (pos.pieces(PAWN) & QueenSide) && (pos.pieces(PAWN) & KingSide);
// Compute the initiative bonus for the attacking side
- int initiative = 8 * (asymmetry + kingDistance - 17) + 12 * pawns + 16 * bothFlanks;
+ int initiative = 8 * (asymmetry + kingDistance - 17) + 12 * pos.count<PAWN>() + 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
- evaluate_passer_pawns<BLACK, DoTrace>(pos, ei);
// Evaluate space for both sides, only during opening
- if (pos.non_pawn_material() >= 12222)
+ if (pos.non_pawn_material() >= SpaceThreshold)
score += evaluate_space<WHITE>(pos, ei)
- evaluate_space<BLACK>(pos, ei);
Trace::add(IMBALANCE, ei.me->imbalance());
Trace::add(PAWN, ei.pe->pawns_score());
Trace::add(MOBILITY, mobility[WHITE], mobility[BLACK]);
- if (pos.non_pawn_material() >= 12222)
+ if (pos.non_pawn_material() >= SpaceThreshold)
Trace::add(SPACE, evaluate_space<WHITE>(pos, ei)
, evaluate_space<BLACK>(pos, ei));
Trace::add(TOTAL, score);
<< " Imbalance | " << Term(IMBALANCE)
<< " Pawns | " << Term(PAWN)
<< " Knights | " << Term(KNIGHT)
- << " Bishop | " << Term(BISHOP)
+ << " Bishops | " << Term(BISHOP)
<< " Rooks | " << Term(ROOK)
<< " Queens | " << Term(QUEEN)
<< " Mobility | " << Term(MOBILITY)
projects / stockfish / blobdiff