Other moves are no better:
A) 20...a5 21.Bb5+–;
B) 20...Bb7 21.axb4 Nxb4 22.b3+–.
A) 20...a5 21.Bb5+–;
B) 20...Bb7 21.axb4 Nxb4 22.b3+–.
22...Nb4? 23.Rxa3 Nxc2 24.Ra2 Nxd4 25.Nxd4 e5 26.Nc6+–.
The last attempt to save the game was 22...e5! 23.Nxe5 Nb4 24.Rxa3 Nxc2 25.Bxb2 Nxa3 26.Bxa3 Re8 27.f4. White is better, but Black has sufficient chances to save the game.
The last attempt to save the game was 22...e5! 23.Nxe5 Nb4 24.Rxa3 Nxc2 25.Bxb2 Nxa3 26.Bxa3 Re8 27.f4. White is better, but Black has sufficient chances to save the game.
For the rook, White has not only two powerful bishops, but also a strong passed pawn on the c-file. The fate of the game is decided.
27...Rfd8 28.g3 Ng6 29.Kg2 Ne7 30.Be3 Nf5 31.Bb6 Rdb8 32.c5 Ne7 33.Bc4 Nd5 34.Bxd5 exd5 35.Nd4 Kf7 36.Nc6 Re8 37.Rd4 Rec8 38.Na5 Ke6 39.Rd2 Rab8 40.Nb3 g6 41.Nd4+ Kd7 42.Nc2 Kc6 43.Nb4+ Kb5 44.Nxd5 a5
A sudden and deadly move. It is possible because the black queen, which has come out ahead of its minor pieces, has very few squares. White defends the weakness on g5, whilst Black has no way to defend the e4-pawn.
The key point lies in the continuation 15...exf3 16.e4 f2+ 17.Ke2!, and the queen is trapped in the centre of the board.
White traps the queen in beautiful style in the variation 16...Nb4 17.Qb1 Nd3+ 18.Qxd3 exd3 19.e4.
White has won the central pawn for no compensation, and gradually realised it.