(14) Q-h7+ K-f6
(15) Q-h8+ K-e7
(16) R-h7+ K-d6
(17) Q-f8+ K-e5
(18) P-f4+ K-d4
(19) Q-f6+ K-e3
(20) R-h3+ K-d2
(21) Q-h4

and Black resigns as there is no defense against Q-f2.

Diagram 51 shows a similar example, the only difference being
that it is not the advance of the Black Knight's Pawn but that of
the Rook's Pawn which gives White an opportunity of opening a
file for his Rooks. He will accomplish this by advancing his
Knight's Pawn to g5 and exchanging him against Black's Rook's
Pawn. If he does not want to play P-g4 on the first move, because
Black could take the Pawn with his Knight, he can prepare the
advance by R-g1. But he need not really fear the loss of the
Pawn, because in taking him Black would himself open the g-file
for White's Rook and White is sure to obtain an overwhelming
attack. It would, of course, be futile for Black to try and stop
the advance of White's g-Pawn by P-g5, as White would then simply
open the Rook's file by P-h4 and Pxg5, quite apart from the fact
that he could sacrifice his Bishop e3 for two Pawns, thereby
depriving Black's King of all protection.

+---------------------------------------+
8 | #R | | #B | #Q | | #R | #K | |
|---------------------------------------|