// friendly pieces.
const Score MobilityBonus[][32] = {
{}, {},
- { S(-65,-50), S(-42,-30), S(-9,-10), S( 3, 0), S(15, 10), S(27, 20), // Knights
- S( 37, 28), S( 42, 31), S(44, 33) },
- { S(-52,-47), S(-28,-23), S( 6, 1), S(20, 15), S(34, 29), S(48, 43), // Bishops
- S( 60, 55), S( 68, 63), S(74, 68), S(77, 72), S(80, 75), S(82, 77),
- S( 84, 79), S( 86, 81) },
- { S(-47,-53), S(-31,-26), S(-5, 0), S( 1, 16), S( 7, 32), S(13, 48), // Rooks
- S( 18, 64), S( 22, 80), S(26, 96), S(29,109), S(31,115), S(33,119),
- S( 35,122), S( 36,123), S(37,124) },
- { S(-42,-40), S(-28,-23), S(-5, -7), S( 0, 0), S( 6, 10), S(11, 19), // Queens
- S( 13, 29), S( 18, 38), S(20, 40), S(21, 41), S(22, 41), S(22, 41),
- S( 22, 41), S( 23, 41), S(24, 41), S(25, 41), S(25, 41), S(25, 41),
- S( 25, 41), S( 25, 41), S(25, 41), S(25, 41), S(25, 41), S(25, 41),
- S( 25, 41), S( 25, 41), S(25, 41), S(25, 41) }
+ { S(-68,-49), S(-46,-33), S(-3,-12), S( 5, -4), S( 9, 11), S(15, 16), // Knights
+ S( 23, 27), S( 33, 28), S(37, 29) },
+ { S(-49,-44), S(-23,-16), S(16, 1), S(29, 16), S(40, 25), S(51, 34), // Bishops
+ S( 55, 43), S( 61, 49), S(64, 51), S(68, 52), S(73, 55), S(75, 60),
+ S( 80, 65), S( 86, 66) },
+ { S(-50,-57), S(-28,-22), S(-11, 7), S(-1, 29), S( 0, 39), S( 1, 46), // Rooks
+ S( 10, 66), S( 16, 79), S(22, 86), S(23,103), S(30,109), S(33,111),
+ S( 37,115), S( 38,119), S(48,124) },
+ { S(-43,-30), S(-27,-15), S( 1, -5), S( 2, -3), S(14, 10), S(18, 24), // Queens
+ S( 20, 27), S( 33, 37), S(33, 38), S(34, 43), S(40, 46), S(43, 56),
+ S( 46, 61), S( 52, 63), S(52, 63), S(57, 65), S(60, 70), S(61, 74),
+ S( 67, 80), S( 76, 82), S(77, 88), S(82, 94), S(86, 95), S(90, 96),
+ S( 94, 99), S( 96,100), S(99,111), S(99,112) }
};
- // Outpost[Bishop/Knight][Square] contains bonuses for knights and bishops
- // outposts, indexed by piece type and square (from white's point of view).
- const Value Outpost[][SQUARE_NB] = {
- {// A B C D E F G H
- V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // Knights
- V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0),
- V(0), V(0), V(4), V(8), V(8), V(4), V(0), V(0),
- V(0), V(4),V(17),V(26),V(26),V(17), V(4), V(0),
- V(0), V(8),V(26),V(35),V(35),V(26), V(8), V(0),
- V(0), V(4),V(17),V(17),V(17),V(17), V(4), V(0) },
- {
- V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // Bishops
- V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0),
- V(0), V(0), V(5), V(5), V(5), V(5), V(0), V(0),
- V(0), V(5),V(10),V(10),V(10),V(10), V(5), V(0),
- V(0),V(10),V(21),V(21),V(21),V(21),V(10), V(0),
- V(0), V(5), V(8), V(8), V(8), V(8), V(5), V(0) }
+ // 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(28, 7), S(42,11) }, // Knights
+ { S(12, 3), S(18, 5) } // Bishops
};
// Threat[defended/weak][minor/major attacking][attacked PieceType] contains
S(0, 0), S(0, 0), S(107, 138), S(84, 122), S(114, 203), S(121, 217)
};
+ const Score ThreatenedByHangingPawn = S(40, 60);
+
// Assorted bonuses and penalties used by evaluation
const Score KingOnOne = S( 2, 58);
const Score KingOnMany = S( 6,125);
}
- // evaluate_outpost() evaluates bishop and knight outpost squares
-
- template<PieceType Pt, Color Us>
- Score evaluate_outpost(const Position& pos, const EvalInfo& ei, Square s) {
-
- const Color Them = (Us == WHITE ? BLACK : WHITE);
-
- assert (Pt == BISHOP || Pt == KNIGHT);
-
- // Initial bonus based on square
- Value bonus = Outpost[Pt == BISHOP][relative_square(Us, s)];
-
- // Increase bonus if supported by pawn, especially if the opponent has
- // no minor piece which can trade with the outpost piece.
- if (bonus && (ei.attackedBy[Us][PAWN] & s))
- {
- if ( !pos.pieces(Them, KNIGHT)
- && !(squares_of_color(s) & pos.pieces(Them, BISHOP)))
- bonus += bonus + bonus / 2;
- else
- bonus += bonus / 2;
- }
-
- return make_score(bonus * 2, bonus / 2);
- }
-
-
// evaluate_pieces() assigns bonuses and penalties to the pieces of a given color
template<PieceType Pt, Color Us, bool Trace>
mobility[Us] += MobilityBonus[Pt][mob];
- // Decrease score if we are attacked by an enemy pawn. The remaining part
- // of threat evaluation must be done later when we have full attack info.
- if (ei.attackedBy[Them][PAWN] & s)
- score -= ThreatenedByPawn[Pt];
-
if (Pt == BISHOP || Pt == KNIGHT)
{
// Bonus for outpost square
- if (!(pos.pieces(Them, PAWN) & pawn_attack_span(Us, s)))
- score += evaluate_outpost<Pt, Us>(pos, ei, s);
+ if ( relative_rank(Us, s) >= RANK_4
+ && !(pos.pieces(Them, PAWN) & pawn_attack_span(Us, s)))
+ score += Outpost[Pt == BISHOP][!!(ei.attackedBy[Us][PAWN] & s)];
// Bonus when behind a pawn
if ( relative_rank(Us, s) < RANK_5
{
// ...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][QUEEN]);
+ | ei.attackedBy[Them][BISHOP]);
if (b)
attackUnits += RookContactCheck * popcount<Max15>(b);
enum { Defended, Weak };
enum { Minor, Major };
- Bitboard b, weak, defended;
+ Bitboard b, weak, defended, safeThreats;
Score score = SCORE_ZERO;
+ // Non-pawn enemies attacked by a pawn
+ weak = (pos.pieces(Them) ^ pos.pieces(Them, PAWN)) & ei.attackedBy[Us][PAWN];
+
+ if (weak)
+ {
+ b = pos.pieces(Us, PAWN) & ( ~ei.attackedBy[Them][ALL_PIECES]
+ | ei.attackedBy[Us][ALL_PIECES]);
+
+ safeThreats = (shift_bb<Right>(b) | shift_bb<Left>(b)) & weak;
+
+ if (weak ^ safeThreats)
+ score += ThreatenedByHangingPawn;
+
+ while (safeThreats)
+ score += ThreatenedByPawn[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];