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.
Ruy Pérez Ponce de León Ruy Pérez Ponce de León Ruy Pérez Ponce de León or Rodrigo Pérez Ponce de León (b. ? - d. 1295) was a Spanish noble of the House of Ponce de León, in the service of the Kingdom of Castile. He was the 15th Grand Master of the Order of Calatrava from 1284 to 1295 under King Sancho IV of Castile and further served as Mayordomo Mayor del Rey from 1293 - 1295, also under Sancho IV. Ruy was the son of the Count of Cabrera, Pedro Ponce de Cabrera and his wife, , one of the illegitimate daughters of