Section B1 – Min Win
{[#] Black threatens six different moves that would allow him to draw. The
most obvious one is 1…Bd6 =.}
1.Nb5 !
( 1.Nd5 ? Bd6 = )
( 1.Bf2 ? Bd6 2.Bg3 Bxg3 = )
1…Bf6
{Renews the same kind of threat, this time on the e5 square.}
( 1…Bg5 2.Bb8 Kf5 3.Kb3 Bf4 4.Nd4+ Ke4 5.Bxf4 Kxf4 6.Kc3 +- {As in
the main line, Black will be checkmated on h1.} )
2.Bb8 Kf5 3.Kb3 !
( 3.Kb1 ? Be5 4.Bxe5 Kxe5 5.Kc2 Ke4 6.Kd2 Kf3 = )
3…Be5 4.Bxe5 Kxe5 5.Kc4 !
( 5.Kc3 ? Ke4 6.Nd4 h5 ! = {Reciprocal zugzwang!} )
5…Ke4 6.Nd4 !
{The first reciprocal zugzwang in the main line, which from here on
becomes an ongoing feature for the next two moves by Black.}
6…h5 7.Kc5 !
( 7.Kc3 Ke3 8.Kc4 Ke4 {waste of time} )
7…h4 8.Kc4 Ke3 9.Kd5 Kf4 10.Ke6 ! +-
{The white king has moved diagonally from a2 to e6 (with a short
deviation) and reached a winning position. From here, the result of
all lines is the same: Black can capture White’s pawn (otherwise he
just loses his own pawn), but will be checkmated on h1. Below a sample
line.}
( 10.Ne6+ Kg4 11.Nd4 Kf4 {waste of time} )
( 10.Ne2+ ? Kf3 11.Nd4+ Kg2 = )
10…Kg4
{Now, it’s checkmate in 23 moves.}
11.Ke5 Kh3 12.Nf3 Kg2
( 12…Kg4 13.Ng1 +- {would lead to a different end when Black does
not capture the h-pawn and instead loses his own. Checkmate in another
20 moves.} )
13.Kf4 h3
( 13…Kh3 {would allow White the additional option to sacrifice the
knight:} 14.Kg5 Kg2 15.Kxh4 Kxf3 16.Kg5 Kg2 17.h4 +- )
14.Ke3 Kf1 15.Kd2 Kg2 16.Ke2 Kh1 17.Nh4 Kg1 18.Ke1 Kh1 19.Kf1 Kxh2 20.Kf2
Kh1 21.Nf5 Kh2
( 21…h2 22.Ng3# )
22.Ne3 Kh1 23.Nf1 h2 24.Ng3# 1-0