Black has played very passively, and now Karpov simply improves his position choking his opponent.
24.Bc5 Ke8 25.d4 Kd7 26.e4 e6 27.b4 Kc8 28.d5 exd5 29.exd5 Rd7 30.d6 Rd8 31.Kg2 Kd7 32.Re2 Kc8 33.Re7 Rd7 34.Ra2 a5 35.Rc2
The best move. White opens the a-file for the rook and the knight on c3 is threatening to jump to e4, which forces Black to play ...d5
White doubles heavy pieces on the a-file to put tremendous pressure against a7.
Passed pawns are also important at the endgame, and even more those who are far away from the king and the rest of pawns. With this sacrifice, Sargissian creates a passed pawn that will leave the knight pretty tied to the rim.
1...Bd8! This was the move that put up more resistance!
1...axb4 2.a5 Kg7 3.a6 Kf8 4.a7 Nb6 5.Ba6 Followed by Bb7 at some point, winning a whole piece.
1...axb4 2.a5 Kg7 3.a6 Kf8 4.a7 Nb6 5.Ba6 Followed by Bb7 at some point, winning a whole piece.
Please note how the black passed pawns (b4 and c6) cannot be pushed and even restrict the black pieces. On the other hand, the white knight and bishop occupy the best squares, attacking and defending simultaneously!
Now we create another passed pawn in the center of the board and involve the king in the action (Kg3-Kf4).