{ S(25, 30), S(36, 35), S(40, 35), S(40, 35),
S(40, 35), S(40, 35), S(36, 35), S(25, 30) } };
- // Backward pawn penalty by opposed flag and file
- const Score Backward[2][FILE_NB] = {
- { S(50, 52), S(63, 56), S(69, 56), S(69, 56),
- S(69, 56), S(69, 56), S(63, 56), S(50, 52) },
- { S(40, 38), S(49, 41), S(53, 41), S(53, 41),
- S(53, 41), S(53, 41), S(49, 41), S(40, 38) } };
+ // Backward pawn penalty by opposed flag
+ const Score Backward[2] = { S(67, 42), S(49, 24) };
// Connected pawn bonus by opposed, phalanx, twice supported and rank
Score Connected[2][2][2][RANK_NB];
// Unsupported pawn penalty
const Score UnsupportedPawnPenalty = S(20, 10);
- // Center bind bonus: Two pawns controlling the same central square
- const Bitboard CenterBindMask[COLOR_NB] = {
- (FileDBB | FileEBB) & (Rank5BB | Rank6BB | Rank7BB),
- (FileDBB | FileEBB) & (Rank4BB | Rank3BB | Rank2BB)
- };
-
const Score CenterBind = S(16, 0);
// Weakness of our pawn shelter in front of the king by [distance from edge][rank]
const Value ShelterWeakness[][RANK_NB] = {
- { V( 99), V(20), V(26), V(54), V(85), V( 92), V(108) },
- { V(117), V( 1), V(27), V(71), V(94), V(104), V(118) },
- { V(104), V( 4), V(51), V(76), V(82), V(102), V( 97) },
- { V( 80), V(12), V(43), V(65), V(88), V( 91), V(115) } };
+ { V( 97), V(21), V(26), V(51), V(87), V( 89), V( 99) },
+ { V(120), V( 0), V(28), V(76), V(88), V(103), V(104) },
+ { V(101), V( 7), V(54), V(78), V(77), V( 92), V(101) },
+ { V( 80), V(11), V(44), V(68), V(87), V( 90), V(119) } };
// Danger of enemy pawns moving toward our king by [type][distance from edge][rank]
const Value StormDanger[][4][RANK_NB] = {
- { { V( 0), V( 65), V( 126), V(36), V(30) },
- { V( 0), V( 55), V( 135), V(36), V(23) },
- { V( 0), V( 47), V( 116), V(45), V(26) },
- { V( 0), V( 62), V( 127), V(57), V(34) } },
- { { V(21), V( 45), V( 93), V(50), V(19) },
- { V(23), V( 24), V( 105), V(41), V(13) },
- { V(23), V( 36), V( 101), V(38), V(20) },
- { V(30), V( 19), V( 110), V(41), V(27) } },
- { { V( 0), V( 0), V( 81), V(14), V( 4) },
- { V( 0), V( 0), V( 169), V(30), V( 3) },
- { V( 0), V( 0), V( 168), V(24), V( 5) },
- { V( 0), V( 0), V( 162), V(26), V(10) } },
- { { V( 0), V(-283), V(-298), V(57), V(29) },
- { V( 0), V( 63), V( 137), V(42), V(18) },
- { V( 0), V( 67), V( 145), V(49), V(33) },
- { V( 0), V( 62), V( 126), V(53), V(21) } } };
+ { { V( 0), V( 67), V( 134), V(38), V(32) },
+ { V( 0), V( 57), V( 139), V(37), V(22) },
+ { V( 0), V( 43), V( 115), V(43), V(27) },
+ { V( 0), V( 68), V( 124), V(57), V(32) } },
+ { { V(20), V( 43), V( 100), V(56), V(20) },
+ { V(23), V( 20), V( 98), V(40), V(15) },
+ { V(23), V( 39), V( 103), V(36), V(18) },
+ { V(28), V( 19), V( 108), V(42), V(26) } },
+ { { V( 0), V( 0), V( 75), V(14), V( 2) },
+ { V( 0), V( 0), V( 150), V(30), V( 4) },
+ { V( 0), V( 0), V( 160), V(22), V( 5) },
+ { V( 0), V( 0), V( 166), V(24), V(13) } },
+ { { V( 0), V(-283), V(-281), V(57), V(31) },
+ { V( 0), V( 58), V( 141), V(39), V(18) },
+ { V( 0), V( 65), V( 142), V(48), V(32) },
+ { V( 0), V( 60), V( 126), V(51), V(19) } } };
// Max bonus for king safety. Corresponds to start position with all the pawns
// in front of the king and no enemy pawn on the horizon.
const Square Right = (Us == WHITE ? DELTA_NE : DELTA_SW);
const Square Left = (Us == WHITE ? DELTA_NW : DELTA_SE);
+ const Bitboard CenterBindMask =
+ Us == WHITE ? (FileDBB | FileEBB) & (Rank5BB | Rank6BB | Rank7BB)
+ : (FileDBB | FileEBB) & (Rank4BB | Rank3BB | Rank2BB);
+
Bitboard b, neighbours, doubled, supported, phalanx;
Square s;
bool passed, isolated, opposed, backward, lever, connected;
Score score = SCORE_ZERO;
- const Square* pl = pos.
list<PAWN>(Us);
+ const Square* pl = pos.
squares<PAWN>(Us);
const Bitboard* pawnAttacksBB = StepAttacksBB[make_piece(Us, PAWN)];
Bitboard ourPawns = pos.pieces(Us , PAWN);
Bitboard theirPawns = pos.pieces(Them, PAWN);
- e->passedPawns[Us] = 0;
+ e->passedPawns[Us] = e->pawnAttacksSpan[Us] = 0;
e->kingSquares[Us] = SQ_NONE;
e->semiopenFiles[Us] = 0xFF;
e->pawnAttacks[Us] = shift_bb<Right>(ourPawns) | shift_bb<Left>(ourPawns);
File f = file_of(s);
- // This file cannot be semi-open
e->semiopenFiles[Us] &= ~(1 << f);
+ e->pawnAttacksSpan[Us] |= pawn_attack_span(Us, s);
// Flag the pawn
neighbours = ourPawns & adjacent_files_bb(f);
// Test for backward pawn.
// If the pawn is passed, isolated, lever or connected it cannot be
// backward. If there are friendly pawns behind on adjacent files
- // it cannot be backward either.
+ // or if it is sufficiently advanced, it cannot be backward either.
if ( (passed | isolated | lever | connected)
- || (ourPawns & pawn_attack_span(Them, s)))
+ || (ourPawns & pawn_attack_span(Them, s))
+ || (relative_rank(Us, s) >= RANK_5))
backward = false;
else
{
score -= Isolated[opposed][f];
else if (backward)
- score -= Backward[opposed][f];
+ score -= Backward[opposed];
else if (!supported)
score -= UnsupportedPawnPenalty;
e->pawnSpan[Us] = b ? int(msb(b) - lsb(b)) : 0;
// Center binds: Two pawns controlling the same central square
- b = shift_bb<Right>(ourPawns) & shift_bb<Left>(ourPawns) & CenterBindMask[Us];
+ b = shift_bb<Right>(ourPawns) & shift_bb<Left>(ourPawns) & CenterBindMask;
score += popcount<Max15>(b) * CenterBind;
return score;
e->key = key;
e->score = evaluate<WHITE>(pos, e) - evaluate<BLACK>(pos, e);
+ e->asymmetry = popcount<Max15>(e->semiopenFiles[WHITE] ^ e->semiopenFiles[BLACK]);
return e;
}
projects / stockfish / blobdiff