In the Sicilian Defence (1. e4 c5), which we looked at in a previous post, after 2. Nf3 d6 the main line is 3. d4 cxd4 but you can often find that players unfamiliar with the Sicilian will play Bc4 as they don’t know to respond with d4 and the bishop line is open so in something of a panic will move the bishop to Bc4 as shown above.
If you’re expecting d4 from white then this can also be a bit of a surprise for black so better to be prepared for it. Nf6 is really the best move attacking the e4 pawn though Nc6 is also possible as you can see from the top image (courtesy of Stockfish) both of which are good development moves so you stick to your game plan. Nf6 prepares for castling on the black kingside and forces white to defend the e4 pawn with d3 which is the best move for white and you see how black is now calling the shots temporarily which will unsettle your opponent if they’re not used to this position.
You might start thinking defensively as white is now attacking the f7 pawn and play e6 but that isn’t the best move and puts no pressure on white meaning they can castle without much thought which is what the beginner player would be looking to do and then by the time you play Nf6 as black white is already safe and black is under pressure to castle so much better to play Nf6 and attack the weaknesses in the white position. Chess can sometimes be a game of distraction so don’t get distracted!
After 1. e4 c5 2. Nf3 d6 3. Bc4 Nf3 4. d3 and Nc6 white has to be careful as he will be tempted to develop his bishop or knight when actually analysis shows 5. c3 should be played to prepare d4 and that’s often a move that white doesn’t want to play as it feels like you’re not developing pieces and attacking which everyone instinctively wants to do. Castling would also be an option for white which many players would do and in that case black should consider g6 which looks like the Sicilian dragon but e6 is equally good preparing d5.
Actually if you’re going to move the bishop then Bb5+ would be a better move and is a popular move in the Sicilian opening which we can look at in another post.