#define S(mg, eg) make_score(mg, eg)
// Isolated pawn penalty by opposed flag
- const Score Isolated[2] = { S(45, 40), S(30, 27) };
+ const Score Isolated[] = { S(45, 40), S(30, 27) };
// Backward pawn penalty by opposed flag
- const Score Backward[2] = { S(56, 33), S(41, 19) };
+ const Score Backward[] = { S(56, 33), S(41, 19) };
// Unsupported pawn penalty for pawns which are neither isolated or backward
const Score Unsupported = S(17, 8);
Score Connected[2][2][2][RANK_NB];
// Doubled pawn penalty
- const Score Doubled = S(18,38);
+ const Score Doubled = S(18, 38);
// Lever bonus by rank
const Score Lever[RANK_NB] = {
};
// Weakness of our pawn shelter in front of the king by [distance from edge][rank].
- // RANK_1 = 0 is used for files where we have no pawns, or where our pawn is behind our king.
+ // RANK_1 = 0 is used for files where we have no pawns or our pawn is behind our king.
const Value ShelterWeakness[][RANK_NB] = {
{ V(100), V(20), V(10), V(46), V(82), V( 86), V( 98) },
{ V(116), V( 4), V(28), V(87), V(94), V(108), V(104) },
// Danger of enemy pawns moving toward our king by [type][distance from edge][rank].
// For the unopposed and unblocked cases, RANK_1 = 0 is used when opponent has no pawn
- // on the given file, or his pawn his behind our king.
+ // on the given file, or their pawn is behind our king.
const Value StormDanger[][4][RANK_NB] = {
{ { V( 0), V(-290), V(-274), V(57), V(41) }, //BlockedByKing
{ V( 0), V( 60), V( 144), V(39), V(13) },
const Square Left = (Us == WHITE ? NORTH_WEST : SOUTH_EAST);
Bitboard b, neighbours, stoppers, doubled, supported, phalanx;
+ Bitboard lever, leverPush, connected;
Square s;
- bool opposed, lever, connected, backward;
+ bool opposed, backward;
Score score = SCORE_ZERO;
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);
// Flag the pawn
opposed = theirPawns & forward_bb(Us, s);
stoppers = theirPawns & passed_pawn_mask(Us, s);
- lever = theirPawns & pawnAttacksBB[s];
- doubled = ourPawns & (s + Up);
+ lever = theirPawns & PawnAttacks[Us][s];
+ leverPush = theirPawns & PawnAttacks[Us][s + Up];
+ doubled = ourPawns & (s - Up);
neighbours = ourPawns & adjacent_files_bb(f);
phalanx = neighbours & rank_bb(s);
supported = neighbours & rank_bb(s - Up);
}
// Passed pawns will be properly scored in evaluation because we need
- // full attack info to evaluate them.
- if (!stoppers && !(ourPawns & forward_bb(Us, s)))
+ // full attack info to evaluate them. Include also not passed pawns
+ // which could become passed after one or two pawn pushes when are
+ // not attacked more times than defended.
+ if ( !(stoppers ^ lever ^ leverPush)
+ && !(ourPawns & forward_bb(Us, s))
+ && popcount(supported) >= popcount(lever)
+ && popcount(phalanx) >= popcount(leverPush))
e->passedPawns[Us] |= s;
+ else if ( stoppers == SquareBB[s + Up]
+ && relative_rank(Us, s) >= RANK_5)
+ {
+ b = shift<Up>(supported) & ~theirPawns;
+ while (b)
+ if (!more_than_one(theirPawns & PawnAttacks[Us][pop_lsb(&b)]))
+ e->passedPawns[Us] |= s;
+ }
+
// Score this pawn
if (!neighbours)
score -= Isolated[opposed];
if (connected)
score += Connected[opposed][!!phalanx][more_than_one(supported)][relative_rank(Us, s)];
- if (doubled)
+ if (doubled && !supported)
score -= Doubled;
if (lever)
b = theirPawns & file_bb(f);
Rank rkThem = b ? relative_rank(Us, frontmost_sq(Them, b)) : RANK_1;
- safety -= ShelterWeakness[std::min(f, FILE_H - f)][rkUs]
+ int d = std::min(f, FILE_H - f);
+ safety -= ShelterWeakness[d][rkUs]
+ StormDanger
[f == file_of(ksq) && rkThem == relative_rank(Us, ksq) + 1 ? BlockedByKing :
rkUs == RANK_1 ? Unopposed :
rkThem == rkUs + 1 ? BlockedByPawn : Unblocked]
- [std::min(f, FILE_H - f)][rkThem];
+ [d][rkThem];
}
return safety;