3 Check Opening Ideas For Black In the French Sicilian: Part 5 (4. Bc4)

• Play Nd4 to threaten Nxf3+. If your opponent takes on d4 then they will no longer have a Knight on f3 defending h4, g5 and h2. These squares can then be targeted by Black's Queen. 
• At some point you can throw in b5 as a pawn sacrifice to open lines for your Queenside pieces.
• It's often a good idea to push your d-pawn to d3 as a pawn sacrifice to disrupt White's development and to open the a7-g1 diagonal.
• Look for opportunities to sacrifice your Queen on h2 or g2.
• Use your h-pawn aggressively to activate your Rook on the h-file.

Where to put your pieces?

• The Queenside Knight goes to d4.
• The Queen usually goes to h4 but should go to c7 instead if White's Bishop is on e2 as the Queen can be vulnerable to Bg4 ideas. The Queen can sometimes also go to g5 if White's Bishop has been lured to b5 with the typical b7-b5 pawn sacrifice.
• The dark squared Bishop usually goes to d6 but can also potentially go to c5.
• The Kingside Knight usually goes to f6 but can also go to h6 or e7.
• The King often stays in the center but can castle Kingside if needed. Castling Queenside is also not out of the question.
• The light squared Bishop goes on the long diagonal (b7 or c6).
• The Kingside Rook is usually used on the h-file.
• The Queenside Rook can sometimes be used to help defend the King in the center if needed.