Figure[Black to move]

The drill repeats. Start by looking for the ingredients of a double attack and work backwards. Does White have any loose pieces? Yes, a bishop at b5 and knight at e5. The question is whether Black can check White's king and attack one of those targets at the same time. The path from a5 to the king is clear, and from a5 the queen also could attack the bishop or knight (this is a classic pattern in the opening; we studied it earlier in the chapter). So you've found a forking square, and now the question is how to get the queen to a5. Black’s own pawn is in the way at c7. Try to clear it in a threatening manner that will require a response from White and give him no time to defend against the coming fork. The simple move c7-c6 attacks the bishop, forcing it to move; wherever it goes, Qa5+ then wins the loose knight.