For the first 29 moves Karpov and I fought tooth and nail and we reached this position. Black's game is solid and the bishops of opposite colors give it a drawing flavor. The only loose pawn on a6 can be protected easily. Karpov finds a way to improve his position and create winning chances.
30.h6
Bf8
Keeping the pawn h6 under observation.
31.Kc3
[Karolyi devotes six pages to 31.g5
The move locks the kingside, protects the h-pawn, but it is not easy to envison how white could break through. Anyway, Karolyi shows the winning ways and concludes that white's king move is the only inaccuracy Karpov made during the entire game.]
31...fxg4
32.Bxg4
Kf7
33.Be6+
Kf6
34.Bg8
[White was able to dribble his bishop to g8, attacking the h-pawn. After 34.Kb4
a5+
35.Kb3
Rc7
36.a3
g5
black is fine.]
34...Rc7
[Surprisingly, the computer engines suggest a pawn sacrifice as the way out. After 34...e6
35.Bxe6
(35.dxe6
Rh5=
; 35.Bxh7
exd5
36.Rg1
(36.Bg8
Bxh6!
37.Rxh6
Kg7=/+
) 36...Rxc4+
37.Kd3
Rxf4
38.Rxg6+
Kf7
the white pieces stumble against each other.) 35...a5
36.Kb3
Rc7
37.Ka4
Rxc4+
38.Kxa5
Be7
white still has some chances. (After 38...Rxf4
39.a4
the passed a-pawn is dangerous.) ]
35.Bxh7
e6
36.Bg8
exd5
37.h7
[37.Bxd5
Rh7=
]
37...Bg7?
[37...Rxc4+!
38.Kd3
(Better seems 38.Kb3
Bg7
39.Bxd5
Rc8
40.Be4
threatening 41.Rg1.) 38...Bg7
39.h8Q?!
(39.Bxd5
would be the only try to win, but after 39...Rc5
40.Ke4
Bh8
41.Rg1
Rb5+/=
black has some chances to hold.) 39...Bxh8
40.Rxh8
and I missed the backward rook move 40...Rc8!
threatening 41...Kg7, black draws. (But not 40...Kg7
41.Bxd5
Rc5
42.Rg8+
Kh7
43.Be6
wins.) ]
38.Bxd5
Bh8
39.Kd3
Kf5
40.Ke3
Re7+
41.Kf3
a5
42.a4
Rc7
43.Be4+
Kf6
44.Rh6
Rg7
[Unfortunately, 44...Kg7
45.Rxg6+
Kxh7
46.Rg1+
Kh6
47.Rh1+
Kg7
48.Rh7+
drops a rook.]
45.Kg4
Black is in zugzwang and must lose the pawn on g6. 1-0