+ RedundantQueen * pieceCount[Us][QUEEN];
// Second-degree polynomial material imbalance by Tord Romstad
- for (pt1 = NO_PIECE_TYPE; pt1 <= QUEEN; pt1++)
+ for (pt1 = NO_PIECE_TYPE; pt1 <= QUEEN; ++pt1)
{
pc = pieceCount[Us][pt1];
if (!pc)
v = LinearCoefficients[pt1];
- for (pt2 = NO_PIECE_TYPE; pt2 <= pt1; pt2++)
+ for (pt2 = NO_PIECE_TYPE; pt2 <= pt1; ++pt2)
v += QuadraticCoefficientsSameColor[pt1][pt2] * pieceCount[Us][pt2]
+ QuadraticCoefficientsOppositeColor[pt1][pt2] * pieceCount[Them][pt2];
}
}
- // No pawns makes it difficult to win, even with a material advantage
+ // No pawns makes it difficult to win, even with a material advantage. This
+ // catches some trivial draws like KK, KBK and KNK
if (!pos.count<PAWN>(WHITE) && npm_w - npm_b <= BishopValueMg)
{
e->factor[WHITE] = (uint8_t)
int minorPieceCount = pos.count<KNIGHT>(WHITE) + pos.count<BISHOP>(WHITE)
+ pos.count<KNIGHT>(BLACK) + pos.count<BISHOP>(BLACK);
- e->spaceWeight = minorPieceCount * minorPieceCount;
+ e->spaceWeight = make_score(minorPieceCount * minorPieceCount, 0);
}
// Evaluate the material imbalance. We use PIECE_TYPE_NONE as a place holder