Jiganchine – Jack Cheng, Keres Memorial 2008
Black to move. How to best deal with the attack against the b5 pawn?
In this position, typical for Archangel-Moller variations of the Spanish opening, my opponent took an "easy" way out and just pushed the pawn forward with 15 … b5-b4 That left him with a severely weakened pawn structure on the queenside, and soon White won a pawn, and later – the game:
16. Nc4 Na5 17. Nxb6 cxb6 18. Bxb7 Nxb7 19. Qb3 a5 20. Qd5 Re7 21. Qc6 +-
The weakness of light squares leads to the loss of the pawn on b6. To paraphrase what David Bronstein said – the weakness of the light squares, manifests itself in opponent coming on those light squares and attacking your pawns and pieces that are placed on dark squares.
Did Black have a better continuation? There was a tactical solution! Black just had to ignore the threat to b5, and protect the bishop with 15 … Ra8-b8! The point reveals itself after: 17. Nxb5 Nxd4!!
This quite a computer trick; my opponent must have missed it and was forced to play the weakening b5-b4; this would have allowed him to equalize, since White does not have anything better than 18. Nbxd4 Bxd5 19. exd5 Rxe1+ 20. Qxe1 Bxd4 =
This is a great example to illustrate the idea that tactics should be used to help your strategy. In this case – Black’s strategy should have been to give up the b5 pawn but actively counter attack White’s center by putting pressure on e4 and d4 with all of Black’s pieces.