Poker is a family of gambling card games involving betting and individual play, whereby the winner is determined by the ranks and combinations of players' cards, some of which remain hidden until the end of the game. Poker games vary in the number of cards dealt, the number of shared or "community" cards, and the number of cards that remain hidden. Betting procedures vary widely among dozens of different poker game variants. In most modern poker games, the first round of betting begins with one or more of the players making some form of a forced bet (the blind and/or ante). In standard poker, each player bets according to the rank he believes his hand is worth as compared to the other players. The action then proceeds clockwise as each player in turn must either match, or "call", the maximum previous bet or fold, losing the amount bet so far and all further interest in the hand. A player who matches a bet may also "raise", or increase the bet. The betting round ends when all players have either matched the last bet or folded. If all but one player folds on any round, the remaining player collects the pot and may choose to show or conceal his hand. If more than one player remains in contention after the final betting round, the hands are revealed, and the player with the winning hand takes the pot. With the exception of initial forced bets, money is only placed into the pot voluntarily by a player who either believes the bet has positive expected value or who is trying to bluff other players for various strategic reasons. Thus, while the outcome of any particular hand significantly involves chance, the long-run expectations of the players are determined by their actions chosen on the basis of probability, psychology, and game theory. Poker has gained in popularity since the beginning of the twentieth century and has gone from being primarily a recreational activity confined to small groups of enthusiasts to a widely popular activity, both for participants and spectators, including online, with many professional players and multimillion-dollar tournament prizes
English actor Joseph Cowell reported in his memoirs that the game was played in New Orleans, Louisiana in 1829, with a deck of 20 cards, and four players betting on which player's hand was the most valuable. Jonathan H. Green's book, An Exposure of the Arts and Miseries of Gambling (G. B. Zieber, Philadelphia, 1843), described the spread of the game from there to the rest of the country by Mississippi riverboats, on which gambling was a common pastime. As it spread north along the Mississippi River and to the West during the gold rush, it is thought to have become a part of the frontier pioneer ethos. Officers of the 114th Pennsylvania Infantry playing cards in front of tents. Petersburg, Virginia, August 1864 Soon after this spread, the full 52-card French deck was used and the flush was introduced. The draw was added prior to 1850 (when it was first mentioned in print in a handbook of games). During the American Civil War, many additions were made including stud poker (specifically five-card stud) and the straight. Further American developments followed, such as the wild card (around 1875), lowball and split-pot poker (around 1900), and community card poker games (around 1925). Modern tournament play became popular in American casinos after the World Series of Poker (WSOP) began in 1970. Among the champions from these early WSOP tournaments were Johnny Moss, Amarillo Slim, Bobby Baldwin, Doyle Brunson, and Puggy Pearson. Later in the 1970s, the first serious poker strategy books appeared, including Super/System by Doyle Brunson and Caro's Book of Poker Tells by Mike Caro , followed later by The Theory of Poker by David Sklansky. By the 1980s, poker was being depicted in popular culture as a commonplace recreational activity. For example, it was featured in at least 10 episodes of Star Trek: The Next Generation as a weekly event of the senior staff of the fictional ship's crew. In the 1990s, poker and casino gambling began to expand across the United States. Poker's popularity experienced an unprecedented spike at the beginning of the 21st century, largely because of the introduction of online poker and hole-card cameras, which turned the game into a spectator sport. Not only could viewers now follow the action and drama of the game on television, but they could also play the game in the comfort of their own homes. In the 2003 World Series of Poker, accountant Chris Moneymaker, who had never played professional poker, won the main event. He won his seat into the $10,000 tournament via a $40 multi-table satellite and turned his $40 into $2.5 million. This helped popularize the game further, which became known as the "Moneymaker effect". Following the surge in popularity, new poker tours soon emerged, including the World Poker Tour and European Poker Tour, both televised, and the latter sponsored by online poker company PokerStars. Subsequent tours have since been created by PokerStars, such as Latin American Poker Tour and Asia Pacific Poker Tour, as well as other national tours. In 2009 the International Federation of Poker was founded in Lausanne, Switzerland, becoming the official governing body for poker and promoting the game as a mind sport. In 2011 it announced plans for two new events: The Nations Cup, a duplicate poker team event, to be staged on the London Eye on the banks of the River Thames and “The Table”, the invitation-only IFP World Championship, featuring roughly 130 of the world’s best poker players, in an event to find the 2011 official "World Champion"