White has more space, and therefore he refrains from exchanges that do not bring him any concrete benefits.
28...Ke7 29.Ra3 Nb6 30.Ke1 Rc8 31.b3 Rcc7 32.Rda1 Bb7 33.Bd1 Bc8 34.bxa4 bxa4 35.Bxa4 f6 36.Bb3 Rxa3 37.Rxa3 g5 38.Kd2 Kd6 39.Ra5 Re7 40.Nc5 f5 41.Nd3 Nd5 42.f3 Rb7 43.Bxd5 exd5 44.Ra8 1-0
Unity Chess Club
Ivan Sokolov 2669 Wang Hao 2696 Sarajevo 2009 Black to move
Black’s main problem is his restricted light-squared bishop. If he is given time, White will play Rf1-f3, and after the queen moves away, the move g2-g4 follows, further restricting Black’s bishop and preparing f4-f5. One can also not rule out the break f4-f5 without the preparatory g2-g4, aiming for an attack on the f-file. Therefore, Black decided on the radical...
It was important to realise that after the opening of the g-file, Black has the resource ...Re8-e6-g6, liquidating the threat of an attack. At the same time, the weakness of the f5-pawn is balanced by that of e3.
Black has no problems at all. The minor pieces with which White might have been able to exploit the f5-pawn have all been exchanged, and Black has substantial pressure on the e- and g-files. Only White has to worry about maintaining the balance, which in the game he was unable to do:
25.Rg1 Rg6 26.Qc2 Qf6 27.Rd1 Re8 28.Qf2 Qe7 29.Rd4 h5 30.a4 Kf8 31.Rd1 Qf6 32.b5 Re4 33.bxa6 bxa6 34.Rb1 Rxa4 35.Rb8+ Kg7 36.Rg3 Re4 37.Rxg6+ fxg6 38.Qa2 Rxe3 39.Qxa6 Qd4 40.Rb1 Qxf4+
Unity Chess Club
Vasily Smyslov Mikhail Tal Moscow ch-URS 1969 White to move
The position is symmetrical, and so is it equal? No! White has the possibility of spoiling his opponent’s pawn structure.
If this were a middlegame, this exchange would have to be very carefully considered, because of the weakening of the light squares around the white king. But here, the king can have no worries, and White can quietly place his pawns on light squares, restricting the enemy bishop. Meanwhile, the knight is ready to head to the weak square in Black’s camp, namely c5.
More chances of a successful defence were offered by 18...Kf7, maintaining the tension on the queenside
19.f3 Bc2 20.Rxd8+ Rxd8 21.Kf2 Kf7 22.b4 Bf5 23.Ke1 e5 24.Nb7 Rd7 25.Na5 c5 26.bxc5 Rd5 27.Nb7 Rd7 28.Nd6+ Ke7 29.g4
Slightly less accurate is 29.e4, since this move limits the manoeuvrability of his own knight.
29...Be6 30.Rb1 Rc7 31.Rb7 Rxb7 32.Nxb7 Kd7 33.Nd6 h6 34.Kf2 Kc6 35.Ke3 a5 36.Ne8 f5 37.Ng7 Bd7 38.gxf5 gxf5 39.f4 Kd5 40.c6 Bc8 41.c7 Kd6 42.h4