Theme: attacking in the endgame with bishops of opposite colours.
Endings with only bishops of opposite colours have a very high drawing tendency, because the bishops live in different worlds and because it is hard to break down any blockade on the squares of the colour not occupied by your bishop. But if more pieces are involved, then the middlegame rule of thumb that bishops of opposite colour favour the attacking side becomes even more important. In the following case, all it takes is a knight for Ivanchuk to come out triumphant:
59.g4!
Shirov had presumably underestimated this breakthrough. The position may still be drawn, but from now on Black has to be very precise in order to keep White's initiative under control.
59...hxg4
60.h5
e4
61.h6
e3+
62.Ke1
Bg8
63.Nxa2
f5
64.Be5
Ke4
65.Bc7
f4
66.Nc3+
Kf5
67.Nd5
Bh7?!
The first step in the wrong direction. [The immediate 67...g3!
leads to a draw easily: 68.Nxf4
(68.Bxf4
Ke4=
) 68...Kg5=
]
68.Ke2!
Black now loses at least a pawn, but not necessarily the game.
68...g3?
It is normally the correct idea when playing aggressively to put the pawns on the opposite colour of squares from the bishop. [But here it was defence with 68...f3+
which was required: 69.Kxe3
Kg5
70.Bf4+
Kf5
and it seems as though White could not break the blockade, because he always has to keep a watchful eye on the black passed pawns, e.g. 71.Ne7+
Kf6
72.Nc6
Kf5
73.Nd4+
Kg6
74.Kf2
Bg8
75.Kg3
Kh7
76.Be3
Bd5
77.Nb5
Be6
78.Nc3
Bd7
79.Ne4
Bf5
80.Nf6+
Kg6
81.Nxg4
Bxg4
82.Kxg4
f2
83.Bxf2
Kxh6=
]
69.Kf3
e2
[69...g2
does not help any more either: 70.Kxg2
e2
71.Kf2
f3
72.Ba5
Ke6
73.Nb6
Kf5
74.Nd7
Kg6
75.Bd2+-
]
70.Kxe2
g2
71.Kf2
f3
72.Bb6
Ke6
73.Nc3
Kf7
74.Be3
Kg6
75.Nd5
Kf7
76.Kxf3
Bb1
77.Nc3
Bc2
78.Kxg2
Kg6
79.Kg3
Kh5
80.Nd5
Kg6
81.Kh4
Bb1
82.Bg5
Bc2
83.Nf6
Bf5
84.h7
... and Shirov resigned. The continuation could have been [84.h7
Kg7
85.h8Q+
Kxh8
86.Bh6
Bd3
87.Bf8
Bc2
88.Kg5
Bd3
89.Kh6
Bc2
90.Bg7#
And this mating position is a nice finish to the attack with opposite coloured bishops.] 1-0