diff --git a/src/evaluate.cpp b/src/evaluate.cpp index 6180c482..84c83269 100644 --- a/src/evaluate.cpp +++ b/src/evaluate.cpp @@ -180,6 +180,16 @@ namespace { S( 9, 10), S( 2, 10), S( 1, -8), S(-20,-12), S(-20,-12), S( 1, -8), S( 2, 10), S( 9, 10) }; + + // Protector[PieceType][distance] contains a protecting bonus for our king, + // indexed by piece type and distance between the piece and the king. + const Score Protector[PIECE_TYPE_NB][8] = { + {}, {}, + { S(0, 0), S( 7, 9), S( 7, 1), S( 1, 5), S(-10,-4), S( -1,-4), S( -7,-3), S(-16,-10) }, // Knight + { S(0, 0), S(11, 8), S(-7,-1), S(-1,-2), S( -1,-7), S(-11,-3), S( -9,-1), S(-16, -1) }, // Bishop + { S(0, 0), S(10, 0), S(-2, 2), S(-5, 4), S( -6, 2), S(-14,-3), S( -2,-9), S(-12, -7) }, // Rook + { S(0, 0), S( 3,-5), S( 2,-5), S(-4, 0), S( -9,-6), S(-4, 7), S(-13,-7), S(-10, -7) } // Queen + }; // Assorted bonuses and penalties used by evaluation const Score MinorBehindPawn = S(16, 0); @@ -294,6 +304,9 @@ namespace { int mob = popcount(b & ei.mobilityArea[Us]); mobility[Us] += MobilityBonus[Pt][mob]; + + // Bonus for this piece as a king protector + score += Protector[Pt][distance(s, pos.square(Us))]; if (Pt == BISHOP || Pt == KNIGHT) {