Sicilian Defence, Chekhover Variation to: Evgeni Vasiukov vs Loek van Wely, 2002 Mikhail Tal vs Robert Eugene Byrne, 1976 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.
Tactical decision game consisted of scenarios that described situations faced by the commanders of battalions, companies, and platoons. In 1982, the Education Center of the United States Marine Corps Development and Education Command used this package as the starting point for a series of three "instructional pamphlets": "Tactical Problems for Battalion Commanders", "Tactical Problems for Platoon Leaders/Company Commanders", and "Tactical Problems for Squad Leaders". In addition to twelve problems taken from "What Now, Lieutenant?", the "Tactical Problems ..." series contained sixteen games that were written expressly for the series by Chief Warrant Officer Bryan N. Lavender, USMC. Like the scenarios in "What Now,