Advance Variation, Milner-Barry Gambit

With 6. Bd3 White abandons the defense of d4 to develop rapidly and castle. The pawn cannot be taken at once: after 6...cxd4 7. cxd4 Nxd4? 8. Nxd4 Qxd4 9. Bb5+, a discovered attack wins Black's queen. Black therefore covers the b5-e8 diagonal with ...Bd7 first, either immediately with 6...Bd7, the most popular reply, or after 6...cxd4 7. cxd4 Bd7. The main line then runs 8. O-O Nxd4 9. Nxd4 Qxd4 10. Nc3, and if Black grabs a second pawn with 10...Qxe5, 11. Re1 brings White a strong initiative on the open files. The Sørensen Variation instead deviates with 9. Ng5, while the Hector Variation, 6...cxd4 7. O-O, delays recapturing on d4. After 6...Bd7, White can also clarify with 7. dxc5 Bxc5 8. O-O, where 8...Ne7?? fails to 9. b4, trapping the bishop. Players reluctant to gamble can answer 6...cxd4 7. cxd4 Bd7 with 8. Be2, guarding d4 with the queen but obtaining a less ambitious game. The engine regards the position as balanced, and White scores slightly better in online play.