National open golf championship

The descriptor "open" is used in a number of sports, and especially in golf, to describe a tournament that is "open" — in theory to all — rather than being closed, i.e., one that is restricted to a particular group. Thus, an amateur tournament, e.g., the U.S. Amateur, is not open, because it is, by definition, closed to professional golfers. The first precise usage of the adjective “open” in golf was in 1861 when the Prestwick Golf Club opened its Medal competition (launched the previous year for professionals only) to amateurs as well; ever since, The Open Championship has been open to all. Any golfer can, in theory, play in The Open either by invitation or by various forms of qualification. In practice, the event is a professional tournament in which a small number of the world’s leading amateurs also play, by invitation or qualification.

Over time the descriptor "open" has been extended to include the premier national tournaments of many countries (starting with the U.S. Open in 1895) and also (mainly in the United States) to some other tournaments, e.g., the Buick Open.

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