A mulligan is a second chance to perform an action, usually after the first chance went wrong through bad luck or a blunder. Its best-known meaning is in golf, whereby a player is informally allowed to replay a stroke, even though this is against the formal rules of golf. The term has also been applied to other sports and games, and to other fields generally. The origin of the term is unclear.

There are many theories about the origin of the term. The United States Golf Association (USGA) cites three stories explaining that the term derived from the name of a Canadian golfer, David Mulligan, one time manager of the Waldorf Astoria Hotel in New York City, who played at the Country Club of Montreal golf course, in Saint-Lambert near Montreal during the 1920s. One version has it that one day after hitting a poor tee shot, Mulligan re-teed and shot again. He called it a "correction shot," but his friends thought it more fitting to name the practice after him. David Mulligan then brought the concept from Canada to the famous U.S. golf club Winged Foot. A second version has the extra shot given to Mulligan due to his being jumpy and shaky after a difficult drive over the Victoria Bridge to the course. The final version of the David Mulligan story gives him an extra shot after having overslept, rushing to get ready to make the tee time.

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