Let’s have another extended look at how Blackburne’s mate can arise, this time from the game that gave the pattern its name. Blackburne, playing the Black pieces, moved his knight to g4. This threatens mate via Qxh2 and therefore forces White to push his h-pawn to h3. Black doesn’t move his knight, though: he keeps the initiative with Bxf2+. This seems to invite White to play RxB, but not really; for notice that with the knight on g4 the f2 square still is attacked twice. This means that if White plays RxBf2, Black can reply QxRf2+ and force White’s king to h1—and then mate with Qf1. So instead White replies to Bxf2 with Kh1. Now we reach the position in the next frame...