Accelerated Dragon, Modern Bc4 Variation

With 7. Bc4, White develops the bishop toward d5 and f7 before committing to f3 and Qd2, so Black cannot answer with the freeing ...d5 that equalizes after 7. f3 O-O 8. Qd2. After the usual 7...O-O, the bishop has to move again with 8. Bb3 before White carries on with f3, Qd2 and O-O-O. Moves played too early allow counterplay against d4 and the e3-bishop: 8. f3 runs into 8...Qb6, and 8. Qd2 into 8...Ng4. The line became popular in the 1950s. In Fischer–Reshevsky, 1958, Black tried to remove the bishop with ...Na5, lost quickly to a sacrifice on f7, and the result secured Fischer the US Championship.

The sideline 7...Qa5 pins the c3-knight and rules out long castling. It sets tactical traps such as 8. Qd2 Nxe4 9. Nxc6 Qxc3 10. Qxc3 Bxc3+ 11. bxc3 dxc6, which favors Black, so White normally unpins with 8. O-O. 7...d6 transposes to the Dragon Variation. The engine rates the position as roughly balanced, and results in online play are close to even.