Scotch Variation Accepted, Main Line

This position is reached by the move order 7...d5 8. exd5 O-O 9. O-O, in which Black delays the recapture on d5 and castles first. White is momentarily a pawn up, but the d5-pawn is weak and Black normally regains it at once. The usual 9...cxd5, chosen in about three games out of four, transposes to the line that arises after 8...cxd5 9. O-O O-O: the c-pawns are undoubled, Black accepts an isolated a-pawn, and play revolves around the open e-file, the half-open b-file and Black's piece activity against White's bishop on d3. Engines consider the position roughly balanced, and results on Lichess are almost even.

The main alternative, 9...Bg4, develops with gain of time against the white queen and postpones taking on d5; Black has scored somewhat better with it. The rare 9...Bxc3 gives up the bishop pair to damage White's queenside structure, and White scores well against it. The 7. Bd3 complex as a whole featured in game five of the 1996 match between Garry Kasparov and Deep Blue.