You might think of Anastasia’s mate as yet another variation on the principle of Greco’s mate—except this time your knight takes the place of the bishop that attacks g8, not of the heavy piece on the h-file. Thus in the diagram Black is mated by White’s rook, since g6 and g8 are sealed off as flight squares by White’s knight. Notice that the mate would work just as well if Black still had a pawn on f7: since the work conventionally done by a bishop instead is being done by a knight, no open line through f7 is necessary. The spots show not only the squares the knight attacks, but also the squares from which the knight can reach the critical e7 square. The f5 and d5 squares are especially common launching pads for this mate, which is another reason why they are powerful outposts for a knight.