What tournament is annually held in Las Vegas since the 1970s?
World Series of Poker The World Series of Poker (WSOP) is a series of poker tournaments held annually in Las Vegas and, since 2005, sponsored by Caesars Entertainment Corporation (known as Harrah's Entertainment until 2010). It dates its origins to 1970, when Benny Binion invited seven of the best-known poker players to the Horseshoe Casino for a single tournament, with a set start and stop time, and a winner determined by a secret ballot of the seven players.
BDO World Darts Championship The BDO World Darts Championship is a world championship competition in darts, organised by the British Darts Organisation (BDO). It began in 1978, and was, alongside the World Darts Federation's World Cup of Darts, one of two world championship tournaments until 1993. Since 1994, following a dispute with the BDO and the subsequent fallout, a breakaway group (originally known as the World Darts Council, and now known as the Professional Darts Corporation) stages its own annual PDC World Championship, generally before the BDO version in late December and early January of each year.