Sicilian Defence, Chekhover Variation Sicilian Defence, Chekhover Variation The Sicilian Defence, Chekhover Variation (also sometimes called the Szily Variation or Hungarian Variation) is a chess opening named after Vitaly Chekhover, from the game Chekhover–Lisitsin, Leningrad 1938. It is defined by the moves: On move four White ignores the standard opening principle to not develop the queen too early in the game. Although the Chekhover Variation is somewhat rare at grandmaster level, it is not uncommon among amateurs. The "Encyclopaedia of Chess Openings" (ECO) assigns code B53 to this opening. Black's main response to the Chekhover Variation is 4... Nc6 immediately attacking White's queen, leading
Ruy Lopez, Exchange Variation than this. White now threatens 6.Nxe5 because the sequence 6...Qd4 7.Nf3 Qxe4 to regain the pawn, now fails to 8.Re1 pinning and winning the queen. "ECO" code C68 examines these responses to 5.0-0: 5...Qf6, 5...Qe7, 5...Bd6, 5...Qd6, or 5...Bg4 (all directly defending the e5-pawn, except 5...Bg4 which indirectly defends by pinning the knight). The moves 5...Be6, 5...Be7, and 5...Ne7 are less common moves which have never achieved popularity. The idea behind these moves is that if White plays to win a pawn with 6.Nxe5, 6...Qd4 7.Nf3 Qxe4 is again playable, as the Black minor piece on e6 or e7 blocks