+ // ThreatBonus[][] contains bonus according to which piece type
+ // attacks which one.
+ #define Z S(0, 0)
+
+ const Score ThreatBonus[8][8] = {
+ { Z, Z, Z, Z, Z, Z, Z, Z }, // not used
+ { Z, S(18,37), Z, S(37,47), S(55,97), S(55,97), Z, Z }, // KNIGHT attacks
+ { Z, S(18,37), S(37,47), Z, S(55,97), S(55,97), Z, Z }, // BISHOP attacks
+ { Z, S( 9,27), S(27,47), S(27,47), Z, S(37,47), Z, Z }, // ROOK attacks
+ { Z, S(27,37), S(27,37), S(27,37), S(27,37), Z, Z, Z }, // QUEEN attacks
+ { Z, Z, Z, Z, Z, Z, Z, Z }, // not used
+ { Z, Z, Z, Z, Z, Z, Z, Z }, // not used
+ { Z, Z, Z, Z, Z, Z, Z, Z } // not used
+ };
+
+ // ThreatedByPawnPenalty[] contains a penalty according to which piece
+ // type is attacked by an enemy pawn.
+ const Score ThreatedByPawnPenalty[8] = {
+ Z, Z, S(56, 70), S(56, 70), S(76, 99), S(86, 118), Z, Z
+ };
+
+ #undef Z
+ #undef S
+
+ // Bonus for unstoppable passed pawns