Chess Opening Theory/1. e4/1...c5/2. Nf3/2...Nc6/3. d4/3...cxd4/4. Nxd4/4...g6/5. Nc3/5...Bg7/6. Be3/6...Nf6

Modern variation B34 Sicilian defence → Accelerated dragon → Modern variation → 6. Be3 6...Nf6 Black develops their knight to its natural square where it controls the centre, and prepares to castle. 7. f3?! is the most common move in amateur games, but it is inaccurate. White thinks to play in the manner of the Yugoslav attack, where f3 is necessary to defend e4 and control g4, preventing ...Ng4 and freeing the queen to move to d2. However, in this line, after 7...O-O 8. Qd2, Black has 8...d5!. Compared to the regular dragon, Black saved a tempo by skipping ...d6 and so played ...d5 one turn earlier, before White has had the chance to long castle. White doesn't have the time to deliver their crushing kingside attack and Black has achieved equality. The modern line is 7. Bc4. By increasing control of d5, White takes the sting out of ...d5 so that they can continue the plan of opposite side castling. It is still possible for White to err in move order here: 7...O-O 8. f3?! is a common inaccuracy on account of 8...Qb6, a double attack on b2 and d4 which threatens the sacrifice ...Nxe4. 8. Be3 must be included to protect b2. 7. Be2, intending 7...O-O 8. O-O, is an alternative. The line continues 8...d5 9. exd5 Nxd5 10. Nxd5 Qxd5 11. Bf3. 7. Nxc6 is another minor side line. This differs from the exchange variation (5. Nxc6) in that White intends 7...bxc6 8. e5, attacking Black's other knight. Theory table 1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4. Nxd4 g6 5. Nc3 Bg7 6. Be3 Nf6 7 Bc4O-O = References