Connects the rooks and after bd3 creates a battery on the b1 h7 diagonal. White's focus is on the h7 pawn.
9... b5 10. Bc4d3 c5 11. dxc5 Nd7xc5 12. Ra1d1
White seeks to own the open d file and creates a discovered attack on black's queen.
12... Nc5xd3
? Black removes the battery but allows white to exchange with the rook and thereby own the d file, attack black's queen, and double rooks on the d file very efficiently. Doubled rooks greatly increase the power of the rooks and create the possibility of a back rank mate on the d8 square. White also has the option of moving qd2 to triple up on the d file and create an almighty cannon to smash into black's territory.
13. Rd1xd3 Qd8c7 14. Rf1d1 O-O
Castling reopens the possibility for white of attacking the h7 square. If white can post his knight on g5 and move black's knight on f6 there is a possibility of a checkmate with qxh7.
15. Bg5f4
Opens up g5 for the knight and attacks black's queen.
15... Qc7b6 16. Bf4d6 Rf8e8 17. Nf3g5
Knight and queen now eye h7. To force the knight on f6 to move and stop protecting h7 white hopes to play the following sequence Bxe7...rxe7; rd8+...re8; rxe8+...nxe8; qxh7+...Kf8; qh8++
17... Nf6d7
? Black doesn't see white's attack on the h7 square.
18. Bd6xe7
If black plays g6 now he is down a piece but he can still save the game.
18... Re8xe7
?? Missed it.
19. Rd3d6
Black's only options to prevent checkmate by qxh7+...kf8; qh8++ are g6 or nf6 but both result in losing his queen. Black resigns.
