Now let's introduce a little complexity. Sometimes, as here, f8 will be open or Black will have time to open it by moving his rook after White plays his queen to the h-file. This gives the king room to flee first to f8 and then to e7. Where this is possible you must satisfy yourself that you can hunt the king down before making the initial sacrifice. The diagram presents a simple example—a skeleton of the position that can arise after the first three moves for each side. If White now plays Qh7+, he blunders away his attack; Black’s king moves to f8 and then escapes to e7. The correct sequence for White here is Qxf7+, Kh8; then QxR#. This idea—starting with Qxf7 rather than Qh7—turns out to be pretty common, so it's important to understand.