42.Nxh6+ Kf8 43.Ng4 b5 44.Ne5 Bc4 45.Nxc4 bxc4 46.Bxc4 Rc8 47.Bb3 Rd8 48.Be6 Rd2+ 49.Kg3 Rxb2 50.Kf3 Ke7 0-1
White shuts off the long diagonal of the black bishop. This proves sufficient for the black king to feel completely undefended.
Other moves do not save him either:
A) 20...dxe5 21.Ngf6+ Kh8 (21...exf6 22.Qxf6 e4 23.c3+–) 22.Qh4 Bxa1 23.Bg7++–;
B) 20...N4xe5 21.Ndf6+ exf6 22.Nxf6+ Kh8 23.Nxe8 Nd3 24.Qxf7+–;
C) 20...N6xe5 21.Nxe7+ Kh8 22.Qf6#.
A) 20...dxe5 21.Ngf6+ Kh8 (21...exf6 22.Qxf6 e4 23.c3+–) 22.Qh4 Bxa1 23.Bg7++–;
B) 20...N4xe5 21.Ndf6+ exf6 22.Nxf6+ Kh8 23.Nxe8 Nd3 24.Qxf7+–;
C) 20...N6xe5 21.Nxe7+ Kh8 22.Qf6#.
He also loses after 21...Qd8 22.Bxc4 (or 22.Bf8 Kxf8 23.Qh6+ Kg8 24.Ngf6+ exf6 25.exf6+–) 22...bxc4 23.exd6 Qxd6 24.Ndf6+ Kh8 25.Bg7++–.
Unity Chess Club
Anton Korobov 2401 Andrei Volokitin 2469 Kharkov ch-UKR 2001 Black to move
The white queen hopes to protect the king by covering the h3-square. But Black interfered with this defence:
Unity Chess Club
Alexander Karpatchev 2570 Alexander Potapov 2475 St Petersburg ch-RUS 1998 Black to move
White’s hopes are bound up with perpetual check on the c8- and f5-squares. Consequently, Black needs to find a way to drive the white queen off this diagonal. In the game, Black missed a chance to end the game beautifully:
Having seen the winning idea, it is easy to find the right way of executing it: first, the white king is driven to a square where the black pawn will queen with check.