Opposite-Color Bishops in the Middlegame

Playing with opposite-color bishops, when there is a comparatively great number of pieces still left on the board, differs from the norm in a great many ways. Here, the ability to mount an attack on the opposing king carries a great deal of weight; because this means the attacker has, effectively, an extra piece, since the opponent’s bishop cannot help at all.

Dydyshko (2480) – S. Kasparov (2315)

Minsk  1997.  Queen's Gambit Accepted [D28]

1.d4 d5 2.c4 dxc4 3.Nf3 Nf6 4.e3 e6 5.Bxc4 a6 6.Qe2 c5 7.dxc5 Bxc5 8.0–0 Nc6 9.e4 Ng4 10.e5 Nd4 11.Nxd4 Qxd4 12.Nd2

White deliberately gives up his center pawn, since he will have plenty of compensation for it.
12...Nxe5 12...Qxe5?? 13.Qxg4i 13.Nb3 Qxc4 14.Qxe5
I have a material advantage already, plus the two bishops. However, the difference in development will be enormous. Now the bishop hangs, as well as the g7-pawn.
14...Bf8 15.Rd1 Qb5 16.Qg3 Bd7 17.Be3 Qh5?! 17...Rc8 was much stronger 18.Qc7! with an attack 18...Bc6 19.Na5!y Bd5 the only move.

Already I could see that Black’s entire defense would hinge on the frontal d5-square; otherwise – it is curtains.
20.Nxb7 Be7?!
20...f6, with the idea of ...Qh5-f7, might have been more accurate.
21.Nd6+?!
Now Black will gladly enter an opposite-color bishop game. 21.Bc5 Bxc5 22.Qxc5 was stronger: Black’s king will not be able to go back, and the attack would be very strong.
21...Bxd6 22.Qxd6
One might expect that the attack would gain power with bishops of opposite colors. And that is what happens here, as we shall see in a few moves.
22...Rd8 22...f6 was better 23.Qa3
Keeping me from castling. I would have been glad to see 23.Qxa6 0-0, since making something out of an advantage in material, with opposite-color bishops and against grandmaster opposition, would have been very difficult.
23...f6
But my king can get around on its own two legs, Ke8-f7.
24.Qxa6?! 24.Rac1 was better 24...0-0
Now I have compensation while White’s advantage has dwindled to practically nothing.
25.Qf1 Bxg2

Now that is what I call an attack on the king – only, it is against White’s king. It is an attractive-looking blow – but I cannot bring myself to give it an exclamation mark, since it is far from being the only way that I could completely equalize the situation! 25...Bxa2= would have been much the same thing in view of the weakness of d1 and his first rank, White would not be able to get that evil black bishop. 25...Bc4 was also quite sufficient: 26.Qe1 Rxd1 27.Rxd1 Bxa2=
26.Kxg2 26.Qxg2?? Rxd1+ 27.Rxd1 Qxd1i+ 26...Qg4+ 27.Kh1 Qf3+ ½-½