The previous section showed how the mating idea we associate with Morphy or Pillsbury—the use of a bishop on the long dark diagonal, plus another piece to seal off g8—can be achieved using a knight as the second piece rather than a rook or queen. The same is true of Greco’s mate. You will recall that Greco’s idea was to direct a bishop against g8 and then seal off the h-file with a heavy piece. Again a knight sometimes can do the work of the heavy pieces, as the diagram here shows, and in at least one sense it can do the work better. Greco’s mate depended on an obstruction at f8 (or a White rook on the f-file) to prevent the king from slipping away along the back rank. But if you have a knight posted on g6, as White does here, it eliminates f8 as well as h8 as flight squares for the enemy king.