In what activity were Garry Kasparov and Bobby Fisher world champions?
Garry Kasparov the Classical Variation of the Caro-Kann Defence and on the Scheveningen Variation of the Sicilian Defence. Kasparov has also contributed extensively to the five-volume openings series "Encyclopedia of Chess Openings". In 2000, Kasparov co-authored "Kasparov Against the World: The Story of the Greatest Online Challenge" with grandmaster Daniel King. The 202-page book analyzes the 1999 Kasparov versus the World game, and holds the record for the longest analysis devoted to a single chess game. In 2003, the first volume of his five-volume work "Garry Kasparov on My Great Predecessors" was published. This volume, which deals with the world chess champions
Garry Kasparov removed Kasparov and Short from the FIDE rating lists. Thus, till this was in effect, there was a parallel rating list presented by PCA which featured all world top players, regardless of their relation to FIDE. There were now two World Champions: PCA champion Kasparov, and FIDE champion Karpov. The title remained split for 13 years. Kasparov defended his title in a 1995 match against Viswanathan Anand at the World Trade Center in New York City. Kasparov won the match by four wins to one, with thirteen draws. It was the last World Championship to be held under the auspices