const Score Unstoppable = S( 0, 20);
const Score Hanging = S(31, 26);
const Score PawnAttackThreat = S(20, 20);
+ const Score PawnSafePush = S( 5 , 5);
// Penalty for a bishop on a1/h1 (a8/h8 for black) which is trapped by
// a friendly pawn on b2/g2 (b7/g7 for black). This can obviously only
score += more_than_one(b) ? KingOnMany : KingOnOne;
}
- // Add bonus for safe pawn pushes which attacks an enemy piece
+ // Add a small bonus for safe pawn pushes
b = pos.pieces(Us, PAWN) & ~TRank7BB;
b = shift_bb<Up>(b | (shift_bb<Up>(b & TRank2BB) & ~pos.pieces()));
b &= ~pos.pieces()
& ~ei.attackedBy[Them][PAWN]
- & (ei.attackedBy[Us][PAWN] | ~ei.attackedBy[Them][ALL_PIECES]);
+ & (ei.attackedBy[Us][ALL_PIECES] | ~ei.attackedBy[Them][ALL_PIECES]);
+ if (b)
+ score += popcount<Full>(b) * PawnSafePush;
+
+ // Add another bonus if the pawn push attacks an enemy piece
b = (shift_bb<Left>(b) | shift_bb<Right>(b))
& pos.pieces(Them)
& ~ei.attackedBy[Us][PAWN];
- if(b)
+ if (b)
score += popcount<Max15>(b) * PawnAttackThreat;
if (Trace)
void init() {
- const double MaxSlope = 8.7;
- const double Peak = 1280;
- double t = 0.0;
+ const int MaxSlope = 8700;
+ const int Peak = 1280000;
+ int t = 0;
- for (int i = 1; i < 400; ++i)
+ for (int i = 0; i < 400; ++i)
{
- t = std::min(Peak, std::min(0.027 * i * i, t + MaxSlope));
- KingDanger[i] = apply_weight(make_score(int(t), 0), Weights[KingSafety]);
+ t = std::min(Peak, std::min(i * i * 27, t + MaxSlope));
+ KingDanger[i] = apply_weight(make_score(t / 1000, 0), Weights[KingSafety]);
}
}