{ S(20, 28), S(29, 31), S(33, 31), S(33, 31),
S(33, 31), S(33, 31), S(29, 31), S(20, 28) } };
- // Connected pawn bonus by opposed, phalanx flags and rank
- Score Connected[2][2][RANK_NB];
+ // Connected pawn bonus by opposed, phalanx, twice supported and rank
+ Score Connected[2][2][2][RANK_NB];
// Levers bonus by rank
const Score Lever[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(23), V(24), V(54), V(85), V( 93), V(107) },
- { V(119), V( 2), V(28), V(72), V(96), V(104), V(114) },
- { V(103), V( 6), V(47), V(74), V(84), V(103), V( 94) },
- { V( 78), V(10), V(41), V(64), V(88), V( 92), V(115) } };
+ { 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) } };
// 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( 125), V(37), V(30) },
- { V( 0), V( 57), V( 136), V(39), V(24) },
- { V( 0), V( 50), V( 114), V(45), V(29) },
- { V( 0), V( 58), V( 129), V(56), V(34) } },
- { { V(20), V( 45), V( 91), V(47), V(20) },
- { V(25), V( 23), V( 105), V(38), V(14) },
- { V(21), V( 37), V( 99), V(35), V(21) },
- { V(30), V( 18), V( 105), V(38), V(28) } },
- { { V( 0), V( 0), V( 81), V(13), V( 4) },
- { V( 0), V( 0), V( 169), V(30), V( 4) },
- { V( 0), V( 0), V( 166), V(24), V( 6) },
- { V( 0), V( 0), V( 164), V(24), V(11) } },
- { { V( 0), V(-289), V(-297), V(57), V(29) },
- { V( 0), V( 66), V( 136), V(43), V(16) },
- { V( 0), V( 66), V( 141), V(50), V(31) },
- { V( 0), V( 63), V( 126), V(52), V(23) } } };
+ { { 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) } } };
// 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 Value MaxSafetyBonus = V(252);
+ const Value MaxSafetyBonus = V(258);
#undef S
#undef V
const Square Right = (Us == WHITE ? DELTA_NE : DELTA_SW);
const Square Left = (Us == WHITE ? DELTA_NW : DELTA_SE);
- Bitboard b, p, doubled, connected;
+ Bitboard b, p, doubled, connected, supported;
Square s;
- bool passed, isolated, opposed, phalanx, backward, unsupported, lever;
+ bool passed, isolated, opposed, phalanx, backward, lever;
Score score = SCORE_ZERO;
const Square* pl = pos.list<PAWN>(Us);
const Bitboard* pawnAttacksBB = StepAttacksBB[make_piece(Us, PAWN)];
e->semiopenFiles[Us] &= ~(1 << f);
// Previous rank
- p = rank_bb(s - pawn_push(Us));
+ p = rank_bb(s - Up);
- // Flag the pawn as passed, isolated, doubled,
- // unsupported or connected (but not the backward one).
+ // Flag the pawn
connected = ourPawns & adjacent_files_bb(f) & (rank_bb(s) | p);
phalanx = connected & rank_bb(s);
- unsupported = !(ourPawns & adjacent_files_bb(f) & p);
+ supported = connected & p;
isolated = !(ourPawns & adjacent_files_bb(f));
doubled = ourPawns & forward_bb(Us, s);
opposed = theirPawns & forward_bb(Us, s);
backward = false;
else
{
- // We now know that there are no friendly pawns beside or behind this
+ // We now know there are no friendly pawns beside or behind this
// pawn on adjacent files. We now check whether the pawn is
// backward by looking in the forward direction on the adjacent
// files, and picking the closest pawn there.
if (isolated)
score -= Isolated[opposed][f];
- if (unsupported && !isolated)
+ if (!supported && !isolated)
score -= UnsupportedPawnPenalty;
if (doubled)
score -= Backward[opposed][f];
if (connected)
- score += Connected[opposed][phalanx][relative_rank(Us, s)];
+ score += Connected[opposed][phalanx][more_than_one(supported)][relative_rank(Us, s)];
if (lever)
score += Lever[relative_rank(Us, s)];
b = e->semiopenFiles[Us] ^ 0xFF;
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];
+ score += popcount<Max15>(b) * CenterBind;
+
return score;
}
for (int opposed = 0; opposed <= 1; ++opposed)
for (int phalanx = 0; phalanx <= 1; ++phalanx)
- for (Rank r = RANK_2; r < RANK_8; ++r)
- {
- int bonus = Seed[r] + (phalanx ? (Seed[r + 1] - Seed[r]) / 2 : 0);
- Connected[opposed][phalanx][r] = make_score(bonus / 2, bonus >> opposed);
- }
+ for (int apex = 0; apex <= 1; ++apex)
+ for (Rank r = RANK_2; r < RANK_8; ++r)
+ {
+ int v = (Seed[r] + (phalanx ? (Seed[r + 1] - Seed[r]) / 2 : 0)) >> opposed;
+ v += (apex ? v / 2 : 0);
+ Connected[opposed][phalanx][apex][r] = make_score(3 * v / 2, v);
+ }
}
projects / stockfish / blobdiff