Figure[White to move]

White has no promising checks or mate threats, and only Black’s rooks (and a pawn) are loose. Experiment with captures to see how they and the responses they force would change the board. White has an interesting one available in Nxe5; Black would reply NxN. Evacuating the knight from f3 would open the familiar line for the queen to reach h5, and from there to check the Black king. Qh5 also would attack the Black knight that would then be at e5.

At first this looks like a perfect double attack, but actually it isn’t; for consider as well what move you then would make if you were in Black’s shoes. As we recently saw, a common hazard of making a knight the object of a double attack is that it can jump out of harm’s way and block the check at the same time. That would happen here: Black would play his attacked knight from e5 to g6. But just keep pushing, always asking what lines would then be open and what checks then would be possible. With White’s queen on h5, Black’s knight over on g6 instead of on c6, and the e5 pawn off the board, White has another, more effective attack: recall that the a8 rook is loose; and now White has a fresh mating threat to create with Qd5, adding to the bishop’s existing attack on f7 (remember that a bishop attacking that square early in the game always is a promising setup for a double attack). After Black fends off the mating threat, White takes the rook with his queen.

If you look at the original position again you might be able to see the outlines of a fork waiting to happen: if White could get his queen onto d5 and clear the c6 knight out of the way, he would win the rook on a8 by creating a mate threat against f7. But making those adjustments takes a couple of moves and requires the queen to take a circuitous route.