Ruy Lopez 5.d4 exd4 6.Qxd4 and White is in . After 4...dxc6, the obvious 5.Nxe5 is weak, since 5...Qd4 6.Nf3 Qxe4+ 7.Qe2 Qxe2+ leaves White with no compensation for Black's bishop pair. There are two principal lines after 4.Bxc6 dxc6. In the late 19th and early 20th centuries, Lasker had great success with 5.d4 exd4 6.Qxd4 Qxd4 7.Nxd4. Since then, better defences for Black have been developed, and this line is considered to slightly favour Black. Jon Jacobs wrote in the July 2005 "Chess Life" (p. 21): "A database search (limited to games longer than 20 moves, both players FIDE 2300+) reveals
Ruy Lopez play 8.c3, Black can and often does play 8...d6, which is just the main line in another order. But he can also play 8...d5 for the Marshall Attack. One of Black's more aggressive alternatives is the Marshall Attack: after 3...a6 4.Ba4 Nf6 5.0-0 Be7 6.Re1 b5 7.Bb3 0-0 8.c3 Black plays the gambit 8...d5, sacrificing a pawn. The main line begins with 9.exd5 Nxd5 (9...e4?!, the Herman Steiner variation, is considered weaker) 10.Nxe5 Nxe5 11.Rxe5 c6 (Marshall's original moves, 11...Nf6, and 11...Bb7 are considered inferior, but have also yielded good results at top levels of play for Black. GM Joel