White has three pieces trained on the Black king’s general position, and the king has little mobility and is short on defenders. These indicators suggest the possibility of a mating attack, but how? The obvious checking idea, Qxf6, almost mates, but the pawn has protection from the rook on f8. The rook cannot be taken, so consider pressuring it. White plays Re8, attacking the rook; this may look counterintuitive because now White’s rook can be taken, but of course if that happens White mates on his next move. In this sense Black’s rook is pinned. The power of Re8 is that it starts a sequence in which White dictates Black’s replies one by one. Here Black has to play Kg7, as it is the only move that avoids immediate mate and provides protection for the rook. White plays RxR; Black plays KxR. Now comes Qxf6+, and Black’s king does not have enough room. White mates a few moves later with his queen and bishop. (After 1. Re8, Kg7; 2. RxR, KxR, the sequence, entirely forced, goes 3. Qxf6+, Ke8; 4. Bf7+, Kd7; 5. Qe6+, Kd8; 6. Qe8#.)