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
Sicilian Defence Closed Sicilian is 2.Nc3 Nc6 3.g3 g6 4.Bg2 Bg7 5.d3 d6 (diagram), when White's main options are 6.Be3 followed by Qd2 and possibly 0-0-0, and 6.f4 followed by Nf3 and 0-0. Other moves besides 2.Nf3 and 2.Nc3 are popular. 2.c3 is the Alapin Variation or c3 Sicilian. Originally championed by Semyon Alapin at the end of the 19th century, it was revived in the late 1960s by Evgeny Sveshnikov and Evgeny Vasiukov. Nowadays its strongest practitioners include grandmasters Sergei Tiviakov and Eduardas Rozentalis. White aims to set up a classical pawn centre with 3.d4, so Black should counter immediately in