There are some situations in chess where you have time to set something up and get it just right, and some where you have to act quickly to take advantage of a temporary situation. One of the commonest sorts of chess mistake consists of thinking a situation is of one type when it is of the other. In the featured game here, black makes a mistake of this type, but is lucky enough to get a chance to put it right.The position above arose in the game Dooley-Oughton. Rob Oughton, black to play here, can make a good central pawn break here with 12...d5, exploiting the inability of the e-pawn to capture it without allowing a fork. This will then give him the opportunity later to decide the central pawn situation in his favour: either he creates a protected passed pawn with ...d4, or he plays ...dxe4 to give himself a mobile pawn majority on the kingside.
Instead, Rob thought he had all the time in the world to make the central pawn break and played 12...Bb7?!, setting up extra protection for the d-pawn when it does go to d5. Play continued 13.Re1 Re8 (he can't now play ...d5 because the e-pawn would hang), reaching the position on the right here:Now white played 14.Bd2?, and black got the second opportunity he'd been waiting for, and played 14...d5, giving him the advantage. He went on to reach a winning position a few moves later.
But there was a way to make things much more difficult for black: 14.c5! cripples the pawn break before it starts. This way, 14...d5 would be harmless because white could just play 15.cxd6, and the positional factors would be slightly in white's favour - the c6 pawn would be isolated and weak. In fact, it's not easy to find a constructive plan for black after 14.c5, simply because so much of his piece placement is devoted to getting ...d5 in.
Indeed, this is a common theme in the opening black chose; in many lines of the Benoni, white snuffs out a potential black pawn roller with a timely a4-a5 advance to make ...b5 impossible without allowing an en passant capture. A common way for black to stop this is to play ...b6 before the pawn reaches a5, thus ensuring that the en passant capture never takes place. The same idea could have happened here as well, with ...d6 on move 12 or 13, which would alter the dynamics of a c5 advance from white.
