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Computer bridge is the playing of the game contract bridge using computer software. After years of limited progress, since around the end of the 20th century the field of computer bridge has made major advances. In 1996 the American Contract Bridge League (ACBL) established an official World Computer-Bridge Championship, to be held annually along with a major bridge event. The first championship took place in 1997 at the North American Bridge Championships in Albuquerque. Since 1999 the event has been conducted as a joint activity of the American Contract Bridge League and the World Bridge Federation. Alvin Levy, ACBL Board member, initiated this championship and has coordinated the event annually since its inception. The event history, articles and publications, analysis, and playing records can be found at the official website.
The World Computer-Bridge Championship is typically played as a round robin followed by a knock-out between the top four contestants. [1] [2] Winners of the annual event are:
Since 2022, "Unofficial Computer Bridge Championships" have been held. [7] The format is a round-robin event, followed by a semi-final and then a final, with scoring in IMPs (and Victory Points may be used to resolve ties). In 2022, due to "technical difficulties" the round-robin was replaced by a quarter-final.
Winners of the annual event are:
In Zia Mahmood's book, Bridge, My Way (1992), Zia offered a £1 million bet that no four-person team of his choosing would be beaten by a computer. A few years later the bridge program GIB (which can stand for either "Ginsberg’s Intelligent Bridgeplayer" or "Goren In a Box"), [8] brainchild of American computer scientist Matthew Ginsberg, [9] proved capable of expert declarer plays like winkle squeezes in play tests. In 1996, Zia withdrew his bet. Two years later, GIB became the world champion in computer bridge, and also had a 12th place score (11210) in declarer play compared to 34 of the top humans in the 1998 Par Contest (including Zia Mahmood). [10] However, such a par contest measures technical bridge analysis skills only[ clarification needed ], and in 1999 Zia beat various computer programs, including GIB, in an individual round robin match. [11]
Further progress in the field of computer bridge has resulted in stronger bridge playing programs, including Jack [12] and Wbridge5. [13] These programs have been ranked highly in national bridge rankings. A series of articles published in 2005 and 2006 in the Dutch bridge magazine IMP describes matches between five-time computer bridge world champion Jack and seven top Dutch pairs including a Bermuda Bowl winner and two reigning European champions. A total of 196 boards were played. Jack defeated three out of the seven pairs (including the European champions). Overall, the program lost by a small margin (359 versus 385 IMPs).[ volume & issue needed ]
In 2009, Phillip Martin, an expert player, began a four-year project in which he played against the champion bridge program, Jack. He played one hand at one table, with Jack playing the other three; at another table, Jack played the same cards at all four seats, producing a comparison result. He posted his results and analysis in a blog he titled The Gargoyle Chronicles. [14] The program was no match for Martin, who won every contest by large margins.
Bridge poses challenges to its players that are different from board games such as chess and go. Most notably, bridge is a stochastic game of incomplete information. At the start of a deal, the information available to each player is limited to just his/her own cards. During the bidding and the subsequent play, more information becomes available via the bidding of the other three players at the table, the cards of the partner of the declarer (the dummy) being put open on the table, and the cards played at each trick. However, it is usually only at the end of the play that full information is obtained.
Today's top-level bridge programs deal with this probabilistic nature by generating many samples representing the unknown hands. Each sample is generated at random, but constrained to be compatible with all information available so far from the bidding and the play. Next, the result of different lines of play are tested against optimal defense for each sample. This testing is done using a so-called "double-dummy solver" that uses extensive search algorithms to determine the optimum line of play for both parties. The line of play that generates the best score averaged over all samples is selected as the optimal play.
Efficient double-dummy solvers are key to successful bridge-playing programs. Also, as the amount of computation increases with sample size, techniques such as importance sampling are used to generate sets of samples that are of minimum size but still representative.
While bridge is a game of incomplete information, a double-dummy solver analyses a simplified version of the game where there is perfect information; the bidding is ignored, the contract (trump suit and declarer) is given, and all players are assumed to know all cards from the very start. The solver can therefore use many of the game tree search techniques typically used in solving two-player perfect-information win/lose/draw games such as chess, go and reversi. However, there are some significant differences.
In comparison to computer chess, computer bridge has not reached world-class level, but the top robots have demonstrated a consistently high level of play. (See analysis of the last few years of play at www.computerbridge.com.) However see below the Philippe Pionchon's article (1984). Yet, whereas computer chess has taught programmers little about building machines that offer human-like intelligence, more intuitive and probabilistic games such as bridge might provide a better testing ground.
The question of whether bridge-playing programs will reach world-class level in the foreseeable future is not easy to answer. Computer bridge has not attracted an amount of interest anywhere near to that of computer chess. On the other hand, much progress has been made in the last decade by researchers working in the field.
Regardless of bridge robots' level of play, computer bridge already has changed the analysis of the game. Commercially available double-dummy programs can solve bridge problems in which all four hands are known, typically within a fraction of a second. These days, few editors of books and magazines will solely rely on humans to analyse bridge problems before publications. Also, more and more bridge players and coaches utilize computer analysis in the post-mortem of a match.
Contract bridge, or simply bridge, is a plain trick-taking card game played with a standard 52-card deck. It is played by two pairs competing against each other, with the partners facing each other as in Whist.
Computer chess includes both hardware and software capable of playing chess. Computer chess provides opportunities for players to practice even in the absence of human opponents, and also provides opportunities for analysis, entertainment and training. Computer chess applications that play at the level of a chess grandmaster or higher are available on hardware from supercomputers to smart phones. Standalone chess-playing machines are also available. Stockfish, Leela Chess Zero, GNU Chess, Fruit, and other free open source applications are available for various platforms.
Computer Go is the field of artificial intelligence (AI) dedicated to creating a computer program that plays the traditional board game Go. The field is sharply divided into two eras. Before 2015, the programs of the era were weak. The best efforts of the 1980s and 1990s produced only AIs that could be defeated by beginners, and AIs of the early 2000s were intermediate level at best. Professionals could defeat these programs even given handicaps of 10+ stones in favor of the AI. Many of the algorithms such as alpha-beta minimax that performed well as AIs for checkers and chess fell apart on Go's 19x19 board, as there were too many branching possibilities to consider. Creation of a human professional quality program with the techniques and hardware of the time was out of reach. Some AI researchers speculated that the problem was unsolvable without creation of human-like AI.
Combinatorial game theory measures game complexity in several ways:
Rubber bridge is a form of contract bridge played by two competing pairs using a particular method of scoring. A rubber is completed when one pair becomes first to win two games, each game presenting a score of 100 or more contract points; a new game ensues until one pair has won two games to conclude the rubber. Owing to the availability of various additional bonus and penalty points in the scoring, it is possible, though less common, to win the rubber by amassing more total points despite losing two games out of three. Rubber bridge involves a high degree of skill but there is also a fair amount of luck involved in who gets the best cards. A popular variation of rubber bridge is known as Chicago.
Duplicate bridge is a variation of contract bridge where the same set of bridge deals are played by different competitors, and scoring is based on relative performance. In this way, every hand, whether strong or weak, is played in competition with others playing identical cards, and the element of skill is heightened while that of chance is reduced. This stands in contrast to Bridge played without duplication, where each hand is freshly dealt and where scores may be more affected by chance in the short run.
In duplicate bridge, a board is an item of equipment that holds one deal, or one deck of 52 cards distributed in four hands of 13 cards each. The design permits the entire deal of four hands to be passed, carried or stacked securely with the cards hidden from view in four pockets. This is required for in-person duplicate bridge tournaments, where the same deal is played several times and so the composition of each hand must be preserved during and after each play of each deal. When bridge is played online, the functions of the physical boards are replaced by the software.
The Bridge World (TBW), the oldest continuously published magazine about contract bridge, was founded in 1929 by Ely Culbertson. It has since been regarded as the game's principal journal, publicizing technical advances in bidding and the play of the cards, discussions of ethical issues, bridge politics and leading personalities, and reports of major tournaments.
These terms are used in contract bridge, using duplicate or rubber scoring. Some of them are also used in whist, bid whist, the obsolete game auction bridge, and other trick-taking games. This glossary supplements the Glossary of card game terms.
While a deal of bridge is always played following a unique set of rules, its scoring may vary depending on the type of event the deal is played on. There are two main categories of scoring: rubber and duplicate. Rubber scoring, and its popular variant Chicago, are mostly used in social play. Duplicate scoring is focused on tournament competition and has many variations that compare and rank the relative performance of partnerships and teams playing the same deals as their competitors.
Alfred (Freddy) Sheinwold was an American bridge player, administrator, international team captain, and prolific writer. He and Edgar Kaplan developed the Kaplan–Sheinwold bidding system. Among other administrative assignments that he accepted, Sheinwold chaired the American Contract Bridge League (ACBL) National Laws Commission from 1964 to 1975, and the ACBL Appeals Committee from 1966 to 1970. He was an editor of The Bridge World monthly magazine from 1934 to 1963 and was the editor of the monthly ACBL members' Bridge Bulletin from 1952 to 1958.
In the card game contract bridge, a suit combination is a specific subset of the cards of one suit held respectively in declarer's and dummy's hands at the onset of play. While the ranks of the remaining cards held by the defenders can be deduced precisely, their location is unknown. Optimum suit combination play allows for all possible lies of the cards held by the defenders.
The Laws of Duplicate Bridge is the official rule book of duplicate bridge promulgated by the World Bridge Federation (WBF). The first Laws of Duplicate Contract Bridge were published in 1928. They were revised in 1933, 1935, 1943, 1949, 1963, 1975, 1987, 1997, 2007 and 2017. The Laws are effective worldwide for all duplicate bridge tournaments sponsored by WBF, zonal, national and subordinate organizations.
Bridge Base Online (BBO) is the world's largest bridge-playing online platform, with about 10 million monthly visits as of November 2021.
Alexander L'vovich Brudno was a Russian computer scientist, best known for fully describing the alpha-beta pruning algorithm. From 1991 until his death he lived in Israel.
Dummy whist is one of many variants of the classic trick-taking card game Whist. The general rules of dummy whist are similar to that of bid whist, with two notable exceptions. Bid whist is played by four players, whereas dummy whist is played by only three. Secondly, instead of dealing a kitty, a dummy hand is dealt to be on the team of the player who wins the auction.
Computer Othello refers to computer architecture encompassing computer hardware and computer software capable of playing the game of Othello. It was notably included in Microsoft Windows from 1.0 to XP, where it is simply known as Reversi.
Computer Arimaa refers to the playing of the board game Arimaa by computer programs.
Cheating in bridge refers to a deliberate violation of the rules of the game of bridge or other unethical behaviour that is intended to give an unfair advantage to a player or team. Cheating can occur in many forms and can take place before, during, or after a board or game.