Unity Chess Club
Artur Jussupow 2630 Alexander Beliavsky 2690 Frankfurt rapid 1998 Black to move
It would appear that the position is roughly equal: the pawns are equal, and the opposite-coloured bishops enhance the drawing tendencies. But these considerations would only be true if queens were not on the board. All the while they are, the possibility exists of a powerful attack on the white king.
Black finds a way to break up White’s pawn chain and get at the white king.
White will not manage to get his attack on the enemy king going. It was essential to switch to defence with 29.Kf3 gxf4 30.exf4, although here too, Black has a serious initiative after 30...Qd4 31.Qd2 Bc5.
Now, the black bishop will join in and White’s position is hardly defensible.
Unity Chess Club
Alexander Khalifman 2655 Friso Nijboer 2605 Groningen 1997 White to move
If White plays 26.a3, Black gets control of the a-file, whilst after 26.b5, Black gets the c5-square. Exploiting the more active position of his pieces, White found a way to break up the black pawn chain:
After 31...Nf8 32.d7 Nxd7 33.Rxe6 Rxe6 34.Bxe6+ Ke7 35.Bg8, Black loses his kingside pawns.
32.Rxe6 Qxb3 33.Re7+ Kf8 34.Rf7+ Kg8 35.Bxb3 b5 36.Rxd7+ c4 37.Re7 Kf8 38.Rxe8+ Kxe8 39.Bc2 Kd7 40.f3 Kxd6 41.Kf2
A technical decision. The position of the Bd4 is undermined, and the pawn on b7 becomes backward.