Look for checks; look for loose enemy pieces; put them together with Qh7—a queen fork that appears on its face to win the rook at c2. But always you have to ask, especially on an open board like this, whether your opponent might be able to move his loose piece out of danger and block the check at the same time. Here White can do this with Rh2. Does this scotch the idea for Black? No; he persists in looking for his next check and sees that Qb1 would then be mate. (Notice how cramped the White king’s position becomes once the rook is on top of it; the Black king at f3 is doing valuable work cutting off flight squares. These cues suggest the importance of looking carefully at the effect of any attacks you can make against White's king.) So if White is alert, Black’s queen fork wins the rook on c2 after all. If White isn’t alert, he is mated. It’s a study in the value of always examining your next check and its consequences, even if the result of the first one you saw was disappointing.