The knight also can fill the role played by a bishop in Morphy’s mate. Here White has the Black king trapped in the corner by his rook, which drives down the open g-file. The rook seals off the king’s only flight squares; any pressure against the king’s position on h8 thus will create checkmate. A bishop on the long diagonal could provide that pressure, but so can a knight stationed on f7. This particular pattern is a little less common because the knight has less flexibility; it has to be on f7, because that is the only square from which it can attack h8 without blocking the g-file. But we will see other uses of this general principle in due course—as when we study the Arabian mate, which is based on a related idea.