Chapter 4 5.bxa6: Early Deviations and Introduction to the Artificial Castling Line 1.d4 Nf6 2.c4 c5 3.d5 b5 4.cxb5 a6 5.bxa6 Acceptance of the Benko Gambit in this way is perhaps the most critical continuation, posing many practical and theoretical problems for Black At the same time, it is the most natural and popular choice, so supporters of the gambit need to be well armed when facing it, knowing a good deal of theory, middlegame motifs, and, last but not least, some typical endings 5.g6 [diagram] A major tabiya for the Benko The main point of this chapter will be positions where White allows the exchange of light-square bishops and then resorts to artificial castling, but of course there are also some lesser-known alternatives, some of which can be described as "oddities" and we will look at them too 6.
Nc3 The main move 6.b3?! is an attempt to oppose bishops on the long diagonal and neutralize the typical Benko pressure. However, it is artificial, and Black is given the chance to obtain a slight plus as follows: 6.Bg7 7.Bb2 0-0 8.g3 White has to resort to an inferior version of a kingside fianchetto here, as otherwise he runs the risk of becoming seriously worse For example, after 8.e3 Nxa6! 9.Nf3 Bb7 10.
Bc4 Nc7u Black recovers the gambit pawn with interest, as he wins the all-important Pd5 under favorable circumstances, with the Bb7 having no opponent on the diagonal a8-h1. 8.Nxa6! Taking on a6 with the knight is best in these positions, as it helps Black apply quickly pressure on d5. 9.Bg2 Bb7 [diagram] 10.Nh3 After 10.e4 e6! 11.Ne2 exd5 12.
exd5 Nb4 13.0-0 Re8! 14.Na3!? (instead, 14.Nbc3?! Ba6! only worsens the white position as the threatened invasion on d3 cannot be prevented by 15.Rb1 due to 15.Nxa2!u) 14.Bxd5 15.Bxd5 Nfxd5 16.
Bxg7 Kxg7 17.Nc2 Qf6 18.a3 Nxc2 19.Qxc2 Qf3 20.Rae1 d6t Black's excellent centralization and higher activity offer him at least a slight edge 10.e6 11.Nf4 Nxd5 12.Bxg7 Kxg7 13.
Nxd5 Bxd5 14.Bxd5 In the event of 14.e4 Bb7 15.0-0 Nb4 16.Nc3 Ba6 17.Re1 d6 18.Qd2 Qc7t Black remains the better side, although White is not without chances. 14.
exd5 15.0-0 [diagram] 15.d4 15.Qf6!? 16.Na3 Nc7 17.Nc2 Rfe8 18.b4! Nb5! 19.bxc5 Nc3 20.
Qd3 Nxe2+ 21.Kg2 Qc3 22.Rfd1 Qxc5 23.Nd4 Qxd4 24.Qxd4+ Nxd4 25.Rxd4 Ra5 26.Rad1 Rxa2 27.Rxd5 Ree2 28.
Rf1 Red2 29.Rxd2 Rxd2t (Endgame 88) is of course drawable but White still has to prove it 16.a3 16.e3! dxe3 17.Nc3!t/= would have given White excellent chances to equalize.