The "Duplicate" variation of which card game is the only IOC recognized card competition? A major championship in this sport is the Bermuda Bowl, held every two years since 1950, though only three times actually in Bermuda. Name this game, supposedly descended from a game called "Russian whist", this game's modern development was pushed by Harold S. Vanderbilt, and in the 1940s was the most popular team card game in the United States.
(contract) Bridge