#define S(mg, eg) make_score(mg, eg)
// Isolated pawn penalty by opposed flag
- const Score Isolated[] = { S(45, 40), S(30, 27) };
+ const Score Isolated[] = { S(27, 30), S(13, 18) };
// Backward pawn penalty by opposed flag
- const Score Backward[] = { S(56, 33), S(41, 19) };
+ const Score Backward[] = { S(40, 26), S(24, 12) };
- // Unsupported pawn penalty for pawns which are neither isolated or backward
- const Score Unsupported = S(17, 8);
-
- // Connected pawn bonus by opposed, phalanx, twice supported and rank
- Score Connected[2][2][2][RANK_NB];
+ // Connected pawn bonus by opposed, phalanx, #support and rank
+ Score Connected[2][2][3][RANK_NB];
// Doubled pawn penalty
const Score Doubled = S(18, 38);
const Square Left = (Us == WHITE ? NORTH_WEST : SOUTH_EAST);
Bitboard b, neighbours, stoppers, doubled, supported, phalanx;
- Bitboard lever, leverPush, connected;
+ Bitboard lever, leverPush;
Square s;
bool opposed, backward;
Score score = SCORE_ZERO;
neighbours = ourPawns & adjacent_files_bb(f);
phalanx = neighbours & rank_bb(s);
supported = neighbours & rank_bb(s - Up);
- connected = supported | phalanx;
// A pawn is backward when it is behind all pawns of the same color on the
// adjacent files and cannot be safely advanced.
// stopper on adjacent file which controls the way to that rank.
backward = (b | shift<Up>(b & adjacent_files_bb(f))) & stoppers;
- assert(!backward || !(pawn_attack_span(Them, s + Up) & neighbours));
+ assert(!(backward && (forward_ranks_bb(Them, s + Up) & neighbours)));
}
// Passed pawns will be properly scored in evaluation because we need
}
// Score this pawn
- if (!neighbours)
+ if (supported | phalanx)
+ score += Connected[opposed][!!phalanx][popcount(supported)][relative_rank(Us, s)];
+
+ else if (!neighbours)
score -= Isolated[opposed];
else if (backward)
score -= Backward[opposed];
- else if (!supported)
- score -= Unsupported;
-
- if (connected)
- score += Connected[opposed][!!phalanx][more_than_one(supported)][relative_rank(Us, s)];
-
if (doubled && !supported)
score -= Doubled;
void init() {
- static const int Seed[RANK_NB] = { 0, 8, 19, 13, 71, 94, 169, 324 };
+ static const int Seed[RANK_NB] = { 0, 13, 24, 18, 76, 100, 175, 330 };
for (int opposed = 0; opposed <= 1; ++opposed)
for (int phalanx = 0; phalanx <= 1; ++phalanx)
- for (int apex = 0; apex <= 1; ++apex)
+ for (int support = 0; support <= 2; ++support)
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(v, v * (r-2) / 4);
+ int v = 17 * support;
+ v += (Seed[r] + (phalanx ? (Seed[r + 1] - Seed[r]) / 2 : 0)) >> opposed;
+
+ Connected[opposed][phalanx][support][r] = make_score(v, v * (r - 2) / 4);
}
}