Sicilian Defence, Katalymov Variation GM Christian Bauer, with which he managed to draw a game in 2005 against currently top-ranked GM Magnus Carlsen. It has also been used by top players such as Gata Kamsky and Soviet GM Lev Psakhis. The opening is named after Soviet IM Boris Katalymov (1932–2013). Bibliography Sicilian Defence, Katalymov Variation In chess, the Katalymov Variation (also spelled Katalimov) is a less popular line of the Sicilian Defence that begins with the moves: The Katalymov is considered inferior since it commits Black to a plan with ...b6 rather than more aggressive Sicilian defences incorporating b7–b5. Black must protect the b5-square,
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