Figure 4.5.1.3[Black to move]

The sight of White’s king and queen on the same line here may seem less conspicuous than the alignments in the other problems of this sort we have seen. Take notice: pieces on squares adjacent to the enemy king can be skewered—especially the queen, which often is a good catch even if the king can protect it when it steps out of the way (an issue we will examine in detail later). But when in doubt you can't go wrong by just looking at every check you can offer. Black has six with his queen that go nowhere and two with his bishop: Be2+, which loses the piece, and Bd5+, which keeps the piece safe and forces the king to move. Safe checks that force the king to move are always of great interest, in part because they may leave whatever lies behind the king exposed. Here Black follows Bd5+ with BxQ.