In his new book "Nunn's Chess Endings Volume 1," the English grandmaster John Nunn discusses a blockading idea that even strong endgame analysts did get wrong. The Russian GM Yuri Averbach, an author of many endgame manuals, could have reached the position on the diagram in his game against Jan Sefc, played in Dresden 1956, but avoided it and only made a draw. Nunn points out how White wins. Can you find it, too?
1.h6!
(Running for the Queen, the h-pawn deflects the black knight to the wrong square.)
1...Nxh6
[1...Kxh6
2.Kxg4
wins.]
2.Be3+
Kh5
3.Bxh6
Kxh6
4.Kh4!
[White still has to be precise. The careless 4.Kg4?
only draws after 4...Kg6!
]
4...Kg6
5.Kg4
(White has the opposition and wins.)
5...Kf6
[5...Kh6
6.Kf5
]
6.Kh5
1-0