const Score Unstoppable = S( 0, 20);
const Score Hanging = S(31, 26);
const Score PawnAttackThreat = S(20, 20);
+ const Score Checked = S(20, 20);
// 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
// Enemy queen safe checks
b = (b1 | b2) & ei.attackedBy[Them][QUEEN];
if (b)
+ {
attackUnits += QueenCheck * popcount<Max15>(b);
+ score -= Checked;
+ }
// Enemy rooks safe checks
b = b1 & ei.attackedBy[Them][ROOK];
if (b)
+ {
attackUnits += RookCheck * popcount<Max15>(b);
+ score -= Checked;
+ }
// Enemy bishops safe checks
b = b2 & ei.attackedBy[Them][BISHOP];
if (b)
+ {
attackUnits += BishopCheck * popcount<Max15>(b);
+ score -= Checked;
+ }
// Enemy knights safe checks
b = pos.attacks_from<KNIGHT>(ksq) & ei.attackedBy[Them][KNIGHT] & safe;
if (b)
+ {
attackUnits += KnightCheck * popcount<Max15>(b);
+ score -= Checked;
+ }
// Finally, extract the king danger score from the KingDanger[]
// array and subtract the score from evaluation.