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{{Short description|Board and dice game for two players}} | {{Short description|Board and dice game for two players}} | ||
{{other uses}} | {{other uses}} | ||
{{Infobox game | {{Infobox game | ||
| italic title = no | | italic title = no | ||
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| skills = {{cslist|[[Strategy game|Strategy]]|[[Tactic (method)|tactics]]|[[counting]]|[[probability]]}} | | skills = {{cslist|[[Strategy game|Strategy]]|[[Tactic (method)|tactics]]|[[counting]]|[[probability]]}} | ||
| related = [[Irish (game)|Irish]], [[Nard (game)|Nard]] | | related = [[Irish (game)|Irish]], [[Nard (game)|Nard]] | ||
| footnotes = Origin: 17th-century England<br/>Descended from: [[Irish (game)|Irish]] | | footnotes = Origin: 17th-century England<br />Descended from: [[Irish (game)|Irish]] | ||
}} | }} | ||
'''Backgammon''' is a two-player [[board game]] played with counters and dice on [[tables board]]s.<!-- "tables" is correct here, not "table" --> It is the most widespread Western member of the large family of [[tables game]]s, whose ancestors date back at least 1,600 years. The earliest record of backgammon itself dates to 17th-century England, being descended from the 16th-century [[Irish (game)|game of Irish]].<ref name=Cram>Forgeng, Johnson and Cram (2003), p. 269.</ref> | '''Backgammon''' is a two-player [[board game]] played with counters and dice on [[tables board]]s.<!-- "tables" is correct here, not "table" --> It is the most widespread Western member of the large family of [[tables game]]s, whose ancestors date back at least 1,600 years. The earliest record of backgammon itself dates to 17th-century England, being descended from the 16th-century [[Irish (game)|game of Irish]].<ref name=Cram>Forgeng, Johnson and Cram (2003), p. 269.</ref> | ||
Backgammon is a two-player game of [[contrary movement]] in which each player has | Backgammon is a two-player game of [[contrary movement]] in which each player has 15 [[piece (tables game)|pieces]] known traditionally as men (short for "tablemen"), but increasingly known as "checkers" in the United States in recent decades.<ref>{{Cite web |title=Backgammon Rules |url=https://www.bkgm.com/rules.html |access-date=2025-11-04 |website=www.bkgm.com}}</ref> The backgammon table pieces move along 24 "[[point (tables game)|points]]" according to the roll of two [[dice]]. The objective of the game is to move the 15 pieces around the board and be first to ''[[bear off]]'', i.e., remove them from the board. The achievement of this while the opponent is still a long way behind results in a triple win known as a ''backgammon'', hence the name of the game. | ||
Backgammon involves a combination of strategy and luck from rolling of the dice. While the dice may determine the outcome of a single game, the better player will accumulate the better record over a series of many games. With each roll of the dice, players must choose from numerous options for moving their pieces and anticipate possible counter-moves by the opponent. The optional use of a doubling cube allows players to raise the stakes during the game. | Backgammon involves a combination of strategy and luck from rolling of the dice. While the dice may determine the outcome of a single game, the better player will accumulate the better record over a series of many games. With each roll of the dice, players must choose from numerous options for moving their pieces and anticipate possible counter-moves by the opponent. The optional use of a doubling cube allows players to raise the stakes during the game. | ||
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[[File:British Museum Royal Game of Ur.jpg|thumb|One of the [[gameboard]]s found by [[Leonard Woolley|Sir Leonard Woolley]] in the [[Royal Cemetery at Ur]] ([[British Museum]])<ref>{{cite web |title=game-board {{!}} British Museum |url=https://www.britishmuseum.org/collection/object/W_1928-1009-378 |website = The British Museum |access-date=18 November 2021 |language=en}}</ref>]] | [[File:British Museum Royal Game of Ur.jpg|thumb|One of the [[gameboard]]s found by [[Leonard Woolley|Sir Leonard Woolley]] in the [[Royal Cemetery at Ur]] ([[British Museum]])<ref>{{cite web |title=game-board {{!}} British Museum |url=https://www.britishmuseum.org/collection/object/W_1928-1009-378 |website = The British Museum |access-date=18 November 2021 |language=en}}</ref>]] | ||
The history of board games can be traced back nearly 5,000 years to archaeological discoveries of the [[Jiroft culture]], | The history of board games can be traced back nearly 5,000 years to archaeological discoveries of the [[Jiroft culture]], in [[Iran]], the world's oldest game set having been discovered in the region with equipment comprising a dumbbell-shaped board, counters and dice. Although its precise rules are unknown, it has been termed the [[Game of 20 Squares]] and [[Irving Finkel]] has suggested a possible reconstruction. The [[Royal Game of Ur]] from 2600 BC may also be an ancestor or intermediate of modern-day table games like backgammon and is the oldest game for which rules have been handed down. It used tetrahedral dice. Various other board games spanning the 10th to 7th centuries BC have been found throughout modern day Iraq, Syria, Egypt and western Iran.<ref name="Iranica board game">{{cite encyclopedia |last1=Schädler |first1=Ulrich |last2=Dunn-Vaturi |first2=Anne-Elizabeth |title=Board Games in pre-Islamic Persia |url=http://www.iranicaonline.org/articles/board-games-in-pre-islamic-persia |encyclopedia=Encyclopædia Iranica |access-date=2018-04-11}}</ref><ref name=":4">{{Cite book|title=Ancient Board Games in Perspective: Papers from the 1990 British Museum Colloquium, with Additional Contributions|last=Becker|first=Andrea|date=2007|publisher=British Museum Press|isbn=9780714111537|editor-last=Finkel|editor-first=Irving|editor-link=Irving Finkel|location=London, England|pages=16|chapter=The Royal Game of Ur|oclc=150371733}}</ref><ref name=":3">{{Cite book|title=It's all a game : the history of board games from Monopoly to Settlers of Catan|last=Donovan|first=Tristan|publisher=Thomas Dunne Books|year=2017|isbn=9781250082725|edition=First|location=New York|pages=13–16|oclc=960239246}}</ref> | ||
==== Sasanian Empire ==== | ==== Sasanian Empire ==== | ||
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==== Western Europe ==== | ==== Western Europe ==== | ||
[[Image:Codex Manesse 262v Herr Goeli.jpg|thumb|upright= | [[Image:Codex Manesse 262v Herr Goeli.jpg|thumb|upright=1.2|Poet [[Herr Goeli]] playing in the 14c, ''[[Codex Manesse]]'', [[Heidelberg University Library]]]] | ||
Tables games first appeared in France during the 11th century and became a favourite pastime of gamblers. In 1254, Louis IX issued a decree prohibiting his court officials and subjects from playing.<ref name="murray">{{cite book |last=Murray |first=H.J.R. |author-link=H. J. R. Murray |chapter=6: Race-Games |title=A History of Board-Games Other than Chess |publisher=Hacker Art Books |year=1952 |isbn=978-0-87817-211-5}}</ref><ref name="lillich">{{cite journal|last=Lillich|first=Meredith Parsons|title=The Tric-Trac Window of Le Mans|journal=The Art Bulletin|volume=65|issue=1|date=March 1983|pages=23–33|doi=10.2307/3050296|jstor=3050296}}</ref> They were played in Germany in the 12th century, and had reached Iceland by the 13th century. In Spain, the [[Alfonso X]] manuscript ''[[Libro de los Juegos]]'', completed in 1283, describes rules for a number of dice and table games in addition to its discussion of [[chess]].<ref name="wollesen">{{cite journal|last=Wollesen|first=Jens T.|title=Sub specie ludi...: Text and Images in Alfonso El Sabio's Libro de Acedrex, Dados e Tablas|journal=Zeitschrift für Kunstgeschichte|volume=53|issue=3|year=1990|pages=277–308|doi=10.2307/1482540|jstor=1482540}}</ref> By the 17th century, games at tables had spread to Sweden. A wooden board and counters were recovered from the wreck of the [[Regalskeppet Vasa|''Vasa'']] among the belongings of the ship's officers. Tables games appear widely in paintings of this period, mainly those of Dutch and German painters, such as [[Adriaen van Ostade|van Ostade]], [[Jan Steen]], [[Hieronymus Bosch]], and [[Pieter Bruegel the Elder|Bruegel]]. Among surviving artworks are [[Cardsharps (Caravaggio)|''Cardsharps'']] by [[Caravaggio]]. | Tables games first appeared in France during the 11th century and became a favourite pastime of gamblers. In 1254, Louis IX issued a decree prohibiting his court officials and subjects from playing.<ref name="murray">{{cite book |last=Murray |first=H.J.R. |author-link=H. J. R. Murray |chapter=6: Race-Games |title=A History of Board-Games Other than Chess |publisher=Hacker Art Books |year=1952 |isbn=978-0-87817-211-5}}</ref><ref name="lillich">{{cite journal|last=Lillich|first=Meredith Parsons|title=The Tric-Trac Window of Le Mans|journal=The Art Bulletin|volume=65|issue=1|date=March 1983|pages=23–33|doi=10.2307/3050296|jstor=3050296}}</ref> They were played in Germany in the 12th century, and had reached Iceland by the 13th century. In Spain, the [[Alfonso X]] manuscript ''[[Libro de los Juegos]]'', completed in 1283, describes rules for a number of dice and table games in addition to its discussion of [[chess]].<ref name="wollesen">{{cite journal|last=Wollesen|first=Jens T.|title=Sub specie ludi...: Text and Images in Alfonso El Sabio's Libro de Acedrex, Dados e Tablas|journal=Zeitschrift für Kunstgeschichte|volume=53|issue=3|year=1990|pages=277–308|doi=10.2307/1482540|jstor=1482540}}</ref> By the 17th century, games at tables had spread to Sweden. A wooden board and counters were recovered from the wreck of the [[Regalskeppet Vasa|''Vasa'']] among the belongings of the ship's officers. Tables games appear widely in paintings of this period, mainly those of Dutch and German painters, such as [[Adriaen van Ostade|van Ostade]], [[Jan Steen]], [[Hieronymus Bosch]], and [[Pieter Bruegel the Elder|Bruegel]]. Among surviving artworks are [[Cardsharps (Caravaggio)|''Cardsharps'']] by [[Caravaggio]]. | ||
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==== Early backgammon ==== | ==== Early backgammon ==== | ||
Backgammon's immediate predecessor was the 16th century tables game of [[Irish (game)|Irish]].<ref name=Cram/> Irish was the Anglo-Scottish equivalent of the French ''Toutes Tables'' and Spanish ''Todas Tablas'', the latter name first being used in the 1283 ''[[El Libro de los Juegos]]'', a translation of Arabic manuscripts by the [[Toledo School of Translators]]. Irish had been popular at the Scottish court of James IV and considered to be "the more serious and solid game" when the variant which became known as Backgammon began to emerge in the first half of the 17th century.<ref name="Howell 1635, Vol. 2, No. 68"/> In medieval Italy, | Backgammon's immediate predecessor was the 16th century tables game of [[Irish (game)|Irish]].<ref name=Cram/> Irish was the Anglo-Scottish equivalent of the French ''Toutes Tables'' and Spanish ''Todas Tablas'', the latter name first being used in the 1283 ''[[El Libro de los Juegos]]'', a translation of Arabic manuscripts by the [[Toledo School of Translators]]. Irish had been popular at the Scottish court of James IV and considered to be "the more serious and solid game" when the variant which became known as Backgammon began to emerge in the first half of the 17th century.<ref name="Howell 1635, Vol. 2, No. 68"/> In medieval Italy, Barail was played on a backgammon board, with the important difference that both players moved their pieces counter-clockwise and starting from the same side of the board.<ref>Murray, H.J.R. 1951. A History of Board-Games Other Than Chess. Oxford: Clarendon Press, p. 122</ref> The game rules for Barail are recorded in a 13th-century manuscript held in the Italian National Library in Florence.<ref>Ms National Library Florence, Banco Rari, 6 p. 2 no. 1</ref> | ||
[[File:Darnica Gurieli by Christoforo de Castelli mid 17th century.jpg|thumb|upright=0.75|A [[Georgians|Georgian]] [[noblewoman]] | [[File:Darnica Gurieli by Christoforo de Castelli mid 17th century.jpg|thumb|upright=0.75|A [[Georgians|Georgian]] [[noblewoman]] | ||
[[Danica (given name)|Darnica]] [[Gurieli]] with backgammon in the foreground, circa 1635]] | [[Danica (given name)|Darnica]] [[Gurieli]] with backgammon in the foreground, circa 1635]] | ||
The earliest mention of backgammon, under the name ''Baggammon'', was by James Howell in a letter dated 1635.<ref>Howell (1650), p. 105.</ref>{{efn|The fact that this is the earliest mention is stated in Fiske (1905), p. 285.}} In English, the word "backgammon" is most likely derived from "back" and {{langx|enm|gamen}}, meaning "game" or "play". Meanwhile, the first use documented by the Oxford English Dictionary was in 1650.<ref name="oed">{{cite book|chapter=backgammon|title=The Oxford English Dictionary|edition=Second|url=http://dictionary.oed.com/|year=1989|access-date=2006-08-05|archive-date=2006-06-25|archive-url=https://web.archive.org/web/20060625103623/http://dictionary.oed.com/|url-status=dead}}</ref> In 1666, it is reported that the "old name for backgammon used by Shakespeare and others" was Tables.<ref>Wheately (1666), p. 70.</ref> However, it is clear from | The earliest mention of backgammon, under the name ''Baggammon'', was by James Howell in a letter dated 1635.<ref>Howell (1650), p. 105.</ref>{{efn|The fact that this is the earliest mention is stated in Fiske (1905), p. 285.}} In English, the word "backgammon" is most likely derived from "back" and {{langx|enm|gamen}}, meaning "game" or "play". Meanwhile, the first use documented by the ''Oxford English Dictionary'' was in 1650.<ref name="oed">{{cite book|chapter=backgammon|title=The Oxford English Dictionary|edition=Second|url=http://dictionary.oed.com/|year=1989|access-date=2006-08-05|archive-date=2006-06-25|archive-url=https://web.archive.org/web/20060625103623/http://dictionary.oed.com/|url-status=dead}}</ref> In 1666, it is reported that the "old name for backgammon used by Shakespeare and others" was Tables.<ref>Wheately (1666), p. 70.</ref> However, it is clear from Willoughby that "tables" was a generic name and that the phrase "playing at tables" was used in a similar way to "playing at cards".<ref name=Willughby>Willughby (c. 1660-1672), entries for "Cards", "Tables", "Irish" and "Back Gammon."</ref> The first known rules of "Back Gammon" were produced by [[Francis Willughby|Francis Willoughby]] around 1672;<ref>Willughby (c. 1672)</ref> they were quickly followed by [[Charles Cotton]] in 1674.<ref>Cotton (1674), pp. 156–158.</ref> | ||
[[Image:Hoyle-backgammon.png|thumb|upright=0.75|right|''A Short Treatise on the Game of Back-Gammon'']] | [[Image:Hoyle-backgammon.png|thumb|upright=0.75|right|''A Short Treatise on the Game of Back-Gammon'']] | ||
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The most recent major development in backgammon was the addition of the doubling cube. Doubles had originally been recorded by placing "common parlour matches" on the bar in the centre of the board.<ref>''The Retail Bookseller'' (1930). p. 34.</ref> A doubling cube was first introduced in the 1920s in New York City among members of gaming clubs on the Lower East Side.<ref name="robertie-501">{{cite book|last=Robertie|first=Bill|author-link=Bill Robertie|title=501 Essential Backgammon Problems|edition=Second Printing|year=2002|page=22|publisher=Cardoza|isbn=978-1-58042-019-8}}</ref> The cube required players not only to select the best move in a given position, but also to estimate the probability of winning from that position, transforming backgammon into the [[expected value]]-driven game played in the 20th and 21st centuries.<ref name="robertie-501"/> | The most recent major development in backgammon was the addition of the doubling cube. Doubles had originally been recorded by placing "common parlour matches" on the bar in the centre of the board.<ref>''The Retail Bookseller'' (1930). p. 34.</ref> A doubling cube was first introduced in the 1920s in New York City among members of gaming clubs on the Lower East Side.<ref name="robertie-501">{{cite book|last=Robertie|first=Bill|author-link=Bill Robertie|title=501 Essential Backgammon Problems|edition=Second Printing|year=2002|page=22|publisher=Cardoza|isbn=978-1-58042-019-8}}</ref> The cube required players not only to select the best move in a given position, but also to estimate the probability of winning from that position, transforming backgammon into the [[expected value]]-driven game played in the 20th and 21st centuries.<ref name="robertie-501"/> | ||
The popularity of backgammon surged in the mid-1960s, in part due to the charisma of [[Prince Alexis Obolensky]] who became known as "The Father of Modern Backgammon".<ref name=GAM>{{cite web|url=http://www.gammonlife.com/news/the_inventor_of_doubling_in_backgammon.htm|title=The Inventor of Doubling in Backgammon|website=www.gammonlife.com}}</ref> "Obe", as he was called by friends, co-founded the International Backgammon Association,<ref>{{cite web|url=http://www.gammonvillage.com/backgammon/news/article_display.cfm?resourceid=937|title=The Father Of Modern Backgammon - GammonVillage Magazine|website=www.gammonvillage.com}}</ref> which published a set of official rules. He also established the World Backgammon Club of Manhattan, devised a backgammon tournament system in 1963, then organized the first major international backgammon tournament in March 1964, which attracted royalty, celebrities and the press. The game became a huge fad and was played on college campuses, in discothèques and at country clubs;<ref name=GAM/> stockbrokers and bankers began playing at conservative men's clubs.<ref name=NYT>{{cite news|title=Urge to Play Backgammon Sweeping Men's Clubs|url=https://www.nytimes.com/1966/01/13/archives/an-old-old-game-gains-new-favor-urge-to-play-backgammon-sweeping.html?sq=Tim%2520Holland%2520backgammon&scp=14&st=cse|quote=A disk and dice game that has been played in Middle Eastern streets for thousands of years, in English homes for hundreds of years, and on Bronx stoops for dozens of years has suddenly gripped the bankers and brokers of old-line men's clubs all over town.|work=[[The New York Times]]|date=January 13, 1966|access-date=2010-09-10 }}</ref> People young and old all across the country dusted off their boards and pieces. Cigarette, liquor and car companies began to sponsor tournaments, and [[Hugh Hefner]] held backgammon parties at the [[Playboy Mansion]].<ref>{{cite web|url=http://www.play65.com/World-Backgammon-Championships-History.html|title=World Backgammon Championships History | The popularity of backgammon surged in the mid-1960s, in part due to the charisma of [[Prince Alexis Obolensky]] who became known as "The Father of Modern Backgammon".<ref name=GAM>{{cite web|url=http://www.gammonlife.com/news/the_inventor_of_doubling_in_backgammon.htm|title=The Inventor of Doubling in Backgammon|website=www.gammonlife.com}}</ref> "Obe", as he was called by friends, co-founded the International Backgammon Association,<ref>{{cite web|url=http://www.gammonvillage.com/backgammon/news/article_display.cfm?resourceid=937|title=The Father Of Modern Backgammon - GammonVillage Magazine|website=www.gammonvillage.com}}</ref> which published a set of official rules. He also established the World Backgammon Club of Manhattan, devised a backgammon tournament system in 1963, then organized the first major international backgammon tournament in March 1964, which attracted royalty, celebrities and the press. The game became a huge fad and was played on college campuses, in discothèques and at country clubs;<ref name=GAM/> stockbrokers and bankers began playing at conservative men's clubs.<ref name=NYT>{{cite news|title=Urge to Play Backgammon Sweeping Men's Clubs|url=https://www.nytimes.com/1966/01/13/archives/an-old-old-game-gains-new-favor-urge-to-play-backgammon-sweeping.html?sq=Tim%2520Holland%2520backgammon&scp=14&st=cse|quote=A disk and dice game that has been played in Middle Eastern streets for thousands of years, in English homes for hundreds of years, and on Bronx stoops for dozens of years has suddenly gripped the bankers and brokers of old-line men's clubs all over town.|work=[[The New York Times]]|date=January 13, 1966|access-date=2010-09-10 }}</ref> People young and old all across the country dusted off their boards and pieces. Cigarette, liquor and car companies began to sponsor tournaments, and [[Hugh Hefner]] held backgammon parties at the [[Playboy Mansion]].<ref name=PLAY65>{{cite web|url=http://www.play65.com/World-Backgammon-Championships-History.html|title=World Backgammon Championships History |website=www.play65.com|access-date=2009-06-06|archive-date=2013-06-28|archive-url=https://web.archive.org/web/20130628003813/http://www.play65.com/World-Backgammon-Championships-History.html|url-status=dead}}</ref> Backgammon clubs were formed and tournaments were held, resulting in a World Championship promoted in Las Vegas in 1967.<ref name=PLAY65/> | ||
In the second half of the 20th century, new terms were introduced in America, such as 'beaver' and 'checkers' for men (although American backgammon experts [[Oswald Jacoby|Jacoby]] and [[John R. Crawford|Crawford]] continued to use both the older terms as well as the new ones).<ref>Jacoby & Crawford (1970), pp. 55 & 188.</ref> | In the second half of the 20th century, new terms were introduced in America, such as 'beaver' and 'checkers' for men (although American backgammon experts [[Oswald Jacoby|Jacoby]] and [[John R. Crawford|Crawford]] continued to use both the older terms as well as the new ones).<ref>Jacoby & Crawford (1970), pp. 55 & 188.</ref> | ||
Most recently, the United States Backgammon Federation (USBGF) was organized in 2009 to repopularize the game in the United States. Board and committee members include many of the top players, tournament directors and writers in the worldwide backgammon community. The USBGF has recently created Standards of Ethical Practice<ref>{{Cite web|title=Standards of Ethical Practice|url=https://usbgf.org/standards-of-ethical-practice/|access-date=2022-12-29|website=U.S. Backgammon Federation|language=en-US}}</ref> to address issues on which tournament rules fail to touch. | Most recently, the United States Backgammon Federation (USBGF) was organized in 2009 to repopularize the game in the United States. Board and committee members include many of the top players, tournament directors and writers in the worldwide backgammon community. The USBGF has recently created Standards of Ethical Practice<ref>{{Cite web|title=Standards of Ethical Practice|url=https://usbgf.org/standards-of-ethical-practice/|access-date=2022-12-29|website=U.S. Backgammon Federation|date=2 February 2021 |language=en-US}}</ref> to address issues on which tournament rules fail to touch. | ||
In its country of origin, the UK Backgammon Federation is the national authority and runs a backgammon {{nowrap|championship{{tsp}}{{mdash}}}}{{tsp}}the Backgammon Galaxy UK Open {{nowrap|Tournament{{tsp}}{{mdash}}}}{{tsp}}as well as club championships, online leagues and knockout tournaments. Like the USBGF they are active members of the [[World Backgammon Federation]] (WBF) and their tournament rules have been adopted in their entirety by the WBF.<ref>{{Cite web|title=What Is The UKBGF?|url=https://ukbgf.com/what-is-the-ukbgf/|access-date=2022-12-29|website=UKBGF|language=en-GB}}</ref> | In its country of origin, the UK Backgammon Federation is the national authority and runs a backgammon {{nowrap|championship{{tsp}}{{mdash}}}}{{tsp}}the Backgammon Galaxy UK Open {{nowrap|Tournament{{tsp}}{{mdash}}}}{{tsp}}as well as club championships, online leagues and knockout tournaments. Like the USBGF they are active members of the [[World Backgammon Federation]] (WBF) and their tournament rules have been adopted in their entirety by the WBF.<ref>{{Cite web|title=What Is The UKBGF?|url=https://ukbgf.com/what-is-the-ukbgf/|access-date=2022-12-29|website=UKBGF|language=en-GB}}</ref> | ||
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Backgammon entered the computer era in the 1990s when software was developed to play and analyze games, and for people to play one another over the internet. | Backgammon entered the computer era in the 1990s when software was developed to play and analyze games, and for people to play one another over the internet. | ||
*''Johnson's Expert Backgammon'', introduced in 1990, was the first commercially available software package to analyze positions and provide stats for wins, losses, gammons, and backgammons. It was based on conventional programming techniques and only achieved a level of play of weak intermediate.<ref name=Bagai>https://static1.squarespace.com/static/536b3994e4b0ef7a9fb66678/t/536d60b5e4b0561102297915/1399677109882/introcbr.pdf</ref> | *''Johnson's Expert Backgammon'', introduced in 1990, was the first commercially available software package to analyze positions and provide stats for wins, losses, gammons, and backgammons. It was based on conventional programming techniques and only achieved a level of play of weak intermediate.<ref name="Bagai">{{Cite web |title=Preface to the Second Edition |url=https://static1.squarespace.com/static/536b3994e4b0ef7a9fb66678/t/536d60b5e4b0561102297915/1399677109882/introcbr.pdf |website=static1.squarespace.com}}</ref> | ||
*''TD-Gammon'', written by Gerry Tesauro at IBM, used [[neural net]] techniques that allowed it to ''learn'' based on experience. A full package with [[Rollout (backgammon)|rollouts]] was never released to the public.<ref name=Bagai /> | *''TD-Gammon'', written by Gerry Tesauro at IBM, used [[neural net]] techniques that allowed it to ''learn'' based on experience. A full package with [[Rollout (backgammon)|rollouts]] was never released to the public.<ref name=Bagai /> | ||
*''JellyFish'', written by Fredriik Dahl and released in 1994, was the first commercially available software based on neural networks, and like TD-Gammon its play approached or surpassed that of the best human players.<ref name=Bagai /> | *''JellyFish'', written by Fredriik Dahl and released in 1994, was the first commercially available software based on neural networks, and like TD-Gammon its play approached or surpassed that of the best human players.<ref name=Bagai /> | ||
*''Snowie'', written by André Nicoulin and Olivier Egger and released in 1998, was a neural-net program that had similar playing strength to its neural net predecessors, but had a more advanced user interface; in particular it could analyze an entire match instead of just one move at a time.<ref name=Bagai /> | *''Snowie'', written by André Nicoulin and Olivier Egger and released in 1998, was a neural-net program that had similar playing strength to its neural net predecessors, but had a more advanced user interface; in particular it could analyze an entire match instead of just one move at a time.<ref name=Bagai /> | ||
*''gnubg'', written by many programmers as part of the [[gnu]] free software project, was released in 2001. It has a similar strength to JellyFish, but is free software. It is still supported and is available for Windows, macOS and most varieties of Linux. Since it is open-source, the source code is publicly available.<ref>https://www.gnu.org/software/gnubg/</ref><ref>{{cite web | title=All About GNU Backgammon | url=https://bkgm.com/gnu/AllAboutGNU.html }}</ref> | *''gnubg'', written by many programmers as part of the [[gnu]] free software project, was released in 2001. It has a similar strength to JellyFish, but is free software. It is still supported and is available for Windows, macOS and most varieties of Linux. Since it is open-source, the source code is publicly available.<ref>{{Cite web |title=GNU Backgammon |url=https://www.gnu.org/software/gnubg/ |archive-url=https://web.archive.org/web/20250720065222/https://www.gnu.org/software/gnubg/ |archive-date=2025-07-20 |access-date=2025-08-02 |website=www.gnu.org |language=en |url-status=live }}</ref><ref>{{cite web | title=All About GNU Backgammon | url=https://bkgm.com/gnu/AllAboutGNU.html }}</ref> | ||
*''[[eXtreme Gammon]]'', written by Xavier Dufaure de Citres and released in 2009, is available for Windows and mobile platforms. According to the ''[[Financial Times]]'', the program is the best backgammon player in the world, and the near-exclusive study tool for all serious backgammon players.<ref name="FT">{{Cite news |last=Roeder |first=Oliver |date=2023-07-28 |title=Backgammon's AI super-brain is for sale |work=Financial Times |url=https://www.ft.com/content/4c01969d-4d79-4feb-8e4f-bfa9833ddfea |access-date=2023-08-01}}</ref> | *''[[eXtreme Gammon]]'', written by Xavier Dufaure de Citres and released in 2009, is available for Windows and mobile platforms. According to the ''[[Financial Times]]'', the program is the best backgammon player in the world, and the near-exclusive study tool for all serious backgammon players.<ref name="FT">{{Cite news |last=Roeder |first=Oliver |date=2023-07-28 |title=Backgammon's AI super-brain is for sale |work=Financial Times |url=https://www.ft.com/content/4c01969d-4d79-4feb-8e4f-bfa9833ddfea |access-date=2023-08-01}}</ref> | ||
Real-time online play began with the First Internet Backgammon Server in July 1992,<ref name="fibs-hist">{{cite web|last=Schneider|first=Andreas|url=http://www.fibs.com/guide.html#history|title=Brief history of FIBS|publisher=FIBS, the First Internet Backgammon Server|access-date=2006-08-05|archive-url=https://web.archive.org/web/20060813210439/http://www.fibs.com/guide.html#history|archive-date=2006-08-13|url-status=dead|display-authors=etal}}</ref> but there are now a range of options.<ref>{{cite web | title=Online Backgammon Sites | url=https://ukbgf.com/backgammon-resources/online-backgammon-sites/ }}</ref><ref>{{cite web|last=Keith|first=Tom|title=Backgammon Play Sites|url=http://www.bkgm.com/servers.html|publisher=Backgammon Galore!|access-date=6 March 2017}}</ref> | Real-time online play began with the First Internet Backgammon Server in July 1992,<ref name="fibs-hist">{{cite web|last=Schneider|first=Andreas|url=http://www.fibs.com/guide.html#history|title=Brief history of FIBS|publisher=FIBS, the First Internet Backgammon Server|access-date=2006-08-05|archive-url=https://web.archive.org/web/20060813210439/http://www.fibs.com/guide.html#history|archive-date=2006-08-13|url-status=dead|display-authors=etal}}</ref> but there are now a range of options.<ref>{{cite web | title=Online Backgammon Sites | url=https://ukbgf.com/backgammon-resources/online-backgammon-sites/ }}</ref><ref>{{cite web|last=Keith|first=Tom|title=Backgammon Play Sites|url=http://www.bkgm.com/servers.html|publisher=Backgammon Galore!|access-date=6 March 2017}}</ref> As the game transitioned into the 21st century, a distinction emerged between the "two worlds" of backgammon: the traditional social game and the computer-optimized competitive scene. <ref>{{Cite web |title=Two Worlds Collide: Casual and Formal Backgammon, by Mark Driver |url=https://bkgm.com/articles/Driver/TwoWorlds/ |access-date=2026-05-04 |website=bkgm.com}}</ref> By 2026, browser-native environments have bridged this gap by serving as onboarding platforms for casual players. Industry analysis highlights that the digital ecosystem now maintains a "dual identity," where high-accessibility web implementations, such as those on 24/7 Backgammon and [[CrazyGames]], act as entry points for newcomers. <ref>{{Cite web |date=2026-03-14 |title=Backgammon Online Games Market Size & Share 2026-2032 |url=https://www.360iresearch.com/library/intelligence/backgammon-online-games |access-date=2026-05-04 |website=360iResearch |language=en}}</ref> These platforms utilize "move-guidance" systems and visual highlights to assist novices in mastering the game's contrary movement and doubling-point logic in a low-pressure environment before they transition to more rigorous analysis tools like [[eXtreme Gammon]]. <ref>{{Cite web |title=Backgammon Online 🎲 Play on CrazyGames |url=https://www.crazygames.com/game/classic-backgammon |access-date=2026-05-04 |website=www.crazygames.com |language=en}}</ref> | ||
== Rules == | == Rules == | ||
[[Image:BackgammonBoard.svg|thumb|Backgammon board in starting position with two dice and a doubling cube]] | [[Image:BackgammonBoard.svg|thumb|Backgammon board in starting position with two dice and a doubling cube]] | ||
[[Image:Bg-movement.svg|thumb|Paths of movement for red and black, with | [[Image:Bg-movement.svg|thumb|Paths of movement for red and black, with pieces in the starting position; viewed from the black side, with home or inner board at lower right]] | ||
Since 2018, backgammon has been overseen internationally by the [[World Backgammon Federation]] who set the rules of play for international tournaments. | Since 2018, backgammon has been overseen internationally by the [[World Backgammon Federation]] who set the rules of play for international tournaments. | ||
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To start the game, each player rolls one die, and the player with the higher number moves first using the numbers shown on both dice. If the players roll the same number, they must roll again until they roll different numbers.<ref>{{cite web|title=Rules of Backgammon|publisher=Backgammon Galore!|url=https://www.bkgm.com/rules.html|quote=To start the game, each player throws a single die. This determines both the player to go first and the numbers to be played.}}</ref> Both dice must land completely flat on the right-hand side of the gameboard. The players then take alternate turns, rolling two dice at the beginning of each turn.<ref name="robertie-winners"/><ref name="hoyle"/> | To start the game, each player rolls one die, and the player with the higher number moves first using the numbers shown on both dice. If the players roll the same number, they must roll again until they roll different numbers.<ref>{{cite web|title=Rules of Backgammon|publisher=Backgammon Galore!|url=https://www.bkgm.com/rules.html|quote=To start the game, each player throws a single die. This determines both the player to go first and the numbers to be played.}}</ref> Both dice must land completely flat on the right-hand side of the gameboard. The players then take alternate turns, rolling two dice at the beginning of each turn.<ref name="robertie-winners"/><ref name="hoyle"/> | ||
After rolling the dice, players must, if possible, move their pieces according to the number shown on each die. For example, if the player rolls a 6 and a 3 (denoted as "6-3"), the player must move one | After rolling the dice, players must, if possible, move their pieces according to the number shown on each die. For example, if the player rolls a 6 and a 3 (denoted as "6-3"), the player must move one piece six points forward, and another or the same piece three points forward. The same piece may be moved twice, as long as the two moves can be made separately and legally: six and then three, or three and then six. If a player rolls two of the same number, called doubles, that player must play each die twice. For example, a roll of 5-5 allows the player to make four moves of five spaces each. On any roll, a player must move according to the numbers on both dice if it is at all possible to do so. If one or both numbers do not allow a legal move, the player forfeits that portion of the roll and the turn ends. If moves can be made according to either one die or the other, but not both, the higher number must be used. If one piece is unable to be moved, but such a move is made possible by the moving of the other piece, that move is compulsory. | ||
In the course of a move, a | In the course of a move, a piece may land on any point that is unoccupied or is occupied by one or more of the player's own pieces. It may also land on a point occupied by exactly one opposing piece, or "[[blot (tables game)|blot]]". In this case, the blot has been "hit" and is placed in the middle of the board on the bar that divides the two sides of the playing surface. A piece may never land on a point occupied by two or more opposing pieces; thus, no point is ever occupied by pieces from both players simultaneously.<ref name="robertie-winners"/><ref name="hoyle"/> There is no limit to the number of pieces that can occupy a point or the bar at any given time. | ||
Pieces placed on the bar must re-enter the game through the opponent's home board before any other move can be made. A roll of 1 allows the piece to enter on the 24-point (opponent's 1), a roll of 2 on the 23-point (opponent's 2), and so forth, up to a roll of 6 allowing entry on the 19-point (opponent's 6). Pieces may not enter on a point occupied by two or more opposing pieces. Pieces can enter on unoccupied points, or on points occupied by a single opposing piece; in the latter case, the single piece is hit and placed on the bar. A player may not move any other pieces until all pieces belonging to that player on the bar have re-entered the board.<ref name="robertie-winners"/><ref name="hoyle"/> If a player has pieces on the bar, but rolls a combination that does not allow any of those pieces to re-enter, the player does not move. If the opponent's home board is completely "closed" (i.e. all six points are each occupied by two or more pieces), there is no roll that will allow a player to enter a piece from the bar, and that player stops rolling and playing until at least one point becomes open (occupied by one or zero pieces) due to the opponent's moves. | |||
A turn ends only when the player has removed his or her dice from the board. Prior to this moment, a move can be undone and replayed an unlimited number of times. | A turn ends only when the player has removed his or her dice from the board. Prior to this moment, a move can be undone and replayed an unlimited number of times. | ||
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=== Bearing off === | === Bearing off === | ||
When all of a player's | When all of a player's pieces are in that player's home board, that player may start removing them; this is called "bearing off". A roll of 1 may be used to bear off a piece from the 1-point, a 2 from the 2-point, and so on. If all of a player's pieces are on points lower than the number showing on a particular die, the player must use that die to bear off one piece from the highest occupied point.<ref name="robertie-winners"/><ref name="hoyle"/> For example, if a player rolls a 6 and a 5, but has no pieces on the 6-point and two on the 5-point, then the 6 and the 5 must be used to bear off the two pieces from the 5-point. | ||
The first player to bear off all fifteen of their own | The first player to bear off all fifteen of their own pieces wins the game. When keeping score in backgammon, the points awarded depend on the scale of the victory. A player who bears off all fifteen pieces when the opponent has borne off at least one, wins a ''single game'' worth 1 point. If all fifteen have been borne off before the opponent gets at least one piece off, this is a ''gammon'' or ''double game'' worth 2 points. A ''backgammon'' or ''triple game'' is worth 3 points and occurs when the losing player has borne off no pieces and has one or more on the bar and/or in the winner's home table (inner board).<ref name="robertie-winners"/><ref name="hoyle"/> | ||
=== Doubling cube === | === Doubling cube === | ||
[[Image:Backgammon DoublingCube.jpg|upright|thumb|Doubling cube]] | [[Image:Backgammon DoublingCube.jpg|upright|thumb|Doubling cube]] | ||
To speed up match play and to provide an added dimension for strategy, a doubling cube is usually used. The doubling cube is not a die to be rolled, but rather a marker, with the numbers 2, 4, 8, 16, 32, and 64 inscribed on its sides to denote the current stake. At the | To speed up match play and to provide an added dimension for strategy, a doubling cube is usually used. The doubling cube is not a die to be rolled, but rather a marker, with the numbers 2, 4, 8, 16, 32, and 64 inscribed on its sides to denote the current stake. At the beginning of the game, the doubling cube is placed halfway between the players, either on the bar or at the side of the board, with the number 64 face up; the cube is then said to be "centered, on 1". When the cube is still centered, either player may start their turn by proposing that the game be played for twice the current stakes. Their opponent must either accept ("take") the doubled stakes or resign ("drop") the game immediately. | ||
Whenever a player accepts doubled stakes, the cube is placed on their side of the board with the corresponding power of two facing upward, to indicate that the right to redouble | Whenever a player accepts doubled stakes, the cube is placed on their side of the board with the corresponding power of two facing upward, to indicate that the right to redouble belongs exclusively to that player.<ref name="robertie-winners"/><ref name="hoyle"/> If the opponent drops the doubled stakes, they lose the game at the current value of the doubling cube. For instance, if the cube showed the number 2 and a player wanted to redouble the stakes to put it at 4, the opponent choosing to drop the redouble would lose two, or twice the original stake.<ref>{{cite web | title=Backgammon FAQ: Basic Rules | url=https://www.bkgm.com/faq/BasicRules.html#the_doubling_cube }}</ref> There is no limit on the number of redoubles. Although 64 is the highest number depicted on the doubling cube, the stakes may rise to 128, 256, and so on. | ||
In money games, a player who accepts a double may immediately "beaver", doubling the value of the game again while retaining possession of the cube.<ref name="bill_robertie-beavers">{{cite web|url=http://www.gammonvillage.com/backgammon/news/early_beavers.cfm|title=Backgammon Beavers|access-date=2007-10-17|last=Robertie|first=Bill|publisher=GammonVillage}}</ref> The player who originally doubled may refuse the beaver, (resign the game and lose the current doubled stakes) or play on with the cube at 4 times its initial value. A player who is beavered may double the stakes once again ("raccoon"); the opponent then has the option of resigning or accepting the raccoon and playing with the cube at 8 times its initial value; in all cases the doubled player retains ownership of the cube. | |||
Some players use the "automatic double rule": If both opponents roll the same opening number, the doubling cube is incremented. When a player decides to double the opponent, the value is then a double of whatever face value is shown (e.g. if there was one automatic double putting the cube up to 2, the first in-game double will be for 4 points). Players usually agree to limit the number of automatic doubles to one per game. The automatic double rule is not an official rule in backgammon, and since it is not used in match play it is rarely, if ever, used in tournaments.<ref>{{cite web | title=Backgammon FAQ: Basic Rules | url=https://www.bkgm.com/faq/BasicRules.html#what_is_an_automatic_double_ }}</ref><ref>{{cite web | title=Backgammon Rules | url=https://www.bkgm.com/rules.html }}</ref> | |||
Some players | |||
The "Jacoby rule", named after [[Oswald Jacoby]], allows gammons and backgammons to count for their respective double and triple values only if the cube has already been offered and accepted. This encourages a player with a large lead to double, possibly ending the game, rather than to play it to conclusion hoping for a gammon or backgammon. The Jacoby rule is widely used in money play but is not used in match play.<ref name="robertie-serious">{{cite book|last=Robertie|first=Bill|author-link=Bill Robertie|title=Backgammon for Serious Players|edition=second|year=2006|pages=19–22|publisher=Cardoza|isbn=978-0-940685-68-0}}</ref> | The "Jacoby rule", named after [[Oswald Jacoby]], allows gammons and backgammons to count for their respective double and triple values only if the cube has already been offered and accepted. This encourages a player with a large lead to double, possibly ending the game, rather than to play it to conclusion hoping for a gammon or backgammon. The Jacoby rule is widely used in money play but is not used in match play.<ref name="robertie-serious">{{cite book|last=Robertie|first=Bill|author-link=Bill Robertie|title=Backgammon for Serious Players|edition=second|year=2006|pages=19–22|publisher=Cardoza|isbn=978-0-940685-68-0}}</ref> | ||
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== Related games == | == Related games == | ||
{{Main|Tables game}} | {{Main|Tables game}} | ||
[[Image:Alfonso-todas-tablas.jpg|thumb|''Todas tablas'' from the ''[[Libro de los juegos]]'']] | [[Image:Alfonso-todas-tablas.jpg|thumb|''Todas tablas'' from the Spanish ''[[Libro de los juegos]]'' (‘Book of Games’)]] | ||
Minor variations to the standard game are common among casual players in certain regions. For instance, only allowing a maximum of five men on any point (Britain)<ref>{{cite web|url=http://www.bkgm.com/variants/OldEnglish.html|title=Old English Backgammon|publisher=Backgammon Galore!}}</ref> or disallowing "hit-and-run" in the home board (Middle East).<ref>{{cite web|url=http://www.bkgm.com/faq/BasicRules.html#is_hit_and_run_allowed_also_known_as_pick_and_pass_|title=Backgammon FAQ: Basic Rules|publisher=Backgammon Galore!}}</ref><ref>{{cite web|url=http://usbgf.org/learn-backgammon/rules-of-backgammon/|title=Backgammon Rules – And How To Play|date=8 May 2021 |publisher=US Backgammon Federation}}</ref> | Minor variations to the standard game are common among casual players in certain regions. For instance, only allowing a maximum of five men on any point (Britain)<ref>{{cite web|url=http://www.bkgm.com/variants/OldEnglish.html|title=Old English Backgammon|publisher=Backgammon Galore!}}</ref> or disallowing "hit-and-run" in the home board (Middle East).<ref>{{cite web|url=http://www.bkgm.com/faq/BasicRules.html#is_hit_and_run_allowed_also_known_as_pick_and_pass_|title=Backgammon FAQ: Basic Rules|publisher=Backgammon Galore!}}</ref><ref>{{cite web|url=http://usbgf.org/learn-backgammon/rules-of-backgammon/|title=Backgammon Rules – And How To Play|date=8 May 2021 |publisher=US Backgammon Federation}}</ref> | ||
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* Money play means that every point counts evenly and every game stands alone, whether money is actually being wagered or not; sometimes it is called ''unlimited'' play. | * Money play means that every point counts evenly and every game stands alone, whether money is actually being wagered or not; sometimes it is called ''unlimited'' play. | ||
* Match play means that the players play until one side scores (or exceeds) a certain number of points. | * Match play means that the players play until one side scores (or exceeds) a certain number of points. | ||
The format has a significant effect on strategy. In a match, the objective is not to win the maximum possible number of points, but rather to simply reach the score needed to win the match, so optimal play may depend on the match score. In money play, the theoretically correct | The format has a significant effect on strategy. In a match, the objective is not to win the maximum possible number of points, but rather to simply reach the score needed to win the match, so optimal play may depend on the match score. In money play, the theoretically correct piece play and cube action would never vary based on the score. | ||
Backgammon has an established [[Backgammon opening theory|opening theory]], although it is less detailed than that of chess. The [[Game tree|tree]] of positions expands rapidly because of the number of possible dice rolls and the moves available on each turn. Recent computer analysis has offered more insight on opening plays, but the midgame is reached quickly. After the opening, backgammon players frequently rely on some established general strategies, combining and switching among them to adapt to the changing conditions of a game. | Backgammon has an established [[Backgammon opening theory|opening theory]], although it is less detailed than that of chess. The [[Game tree|tree]] of positions expands rapidly because of the number of possible dice rolls and the moves available on each turn. Recent computer analysis has offered more insight on opening plays, but the midgame is reached quickly. After the opening, backgammon players frequently rely on some established general strategies, combining and switching among them to adapt to the changing conditions of a game. | ||
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* The ''running game'' is a strategy minimizing or breaking contact while ahead in the race.<ref name="magriel">{{cite book|last=Magriel|first=Paul|author-link=Paul Magriel|title=Backgammon|year=1976|publisher=Quadrangle/The New York Times Book Co|isbn=978-0-8129-0615-8}}</ref> | * The ''running game'' is a strategy minimizing or breaking contact while ahead in the race.<ref name="magriel">{{cite book|last=Magriel|first=Paul|author-link=Paul Magriel|title=Backgammon|year=1976|publisher=Quadrangle/The New York Times Book Co|isbn=978-0-8129-0615-8}}</ref> | ||
* <div>The ''holding game'' is holding a point on the opponent's side of the board, called an anchor. As the game progresses, the player may gain an advantage by hitting an opponent's blot from the anchor or by rolling large doubles that allow the | * <div>The ''holding game'' is holding a point on the opponent's side of the board, called an anchor. As the game progresses, the player may gain an advantage by hitting an opponent's blot from the anchor or by rolling large doubles that allow the pieces to escape into a running game.<ref name="magriel"/></div> | ||
* The ''priming game'' involves building a wall of | * The ''priming game'' involves building a wall of pieces, called a prime, covering a number of consecutive points. This obstructs opposing pieces that are behind the prime. A piece trapped behind a six-point prime cannot escape until the prime is broken.<ref name="magriel"/> | ||
* <div>The ''attacking game'', sometimes called a ''blitz'', is a strategy of covering the home board as quickly as possible while hitting one's opponent and keeping them on the bar. Because the opponent has difficulty re-entering from the bar or escaping, a player can quickly gain a race advantage and win the game, often with a gammon.<ref name="robertie-winners"/></div> | * <div>The ''attacking game'', sometimes called a ''blitz'', is a strategy of covering the home board as quickly as possible while hitting one's opponent and keeping them on the bar. Because the opponent has difficulty re-entering from the bar or escaping, a player can quickly gain a race advantage and win the game, often with a gammon.<ref name="robertie-winners"/></div> | ||
A ''backgame'' is a strategy that involves holding two or more anchors in an opponent's home board while being substantially behind in the race.<ref>{{cite web|url=http://www.bkgm.com/gloss/lookup.cgi?back+game%20game|title=Backgammon Glossary/Back Game|publisher=Backgammon Galore!}}</ref> The anchors obstruct the opponent's | A ''backgame'' is a strategy that involves holding two or more anchors in an opponent's home board while being substantially behind in the race.<ref>{{cite web|url=http://www.bkgm.com/gloss/lookup.cgi?back+game%20game|title=Backgammon Glossary/Back Game|publisher=Backgammon Galore!}}</ref> The anchors obstruct the opponent's pieces and create opportunities to hit them as they move home. The backgame is generally used only to salvage a game wherein a player is already significantly behind. Using a backgame as an initial strategy is usually unsuccessful.<ref name="robertie-winners"/><ref name="magriel"/> | ||
''Duplication'' refers to the placement of | ''Duplication'' refers to the placement of pieces such that one's opponent needs the same dice rolls to achieve different goals. For example, players may position all of their blots in such a way that the opponent must roll a 2 in order to hit any of them, reducing the probability of being hit more than once.<ref name="robertie-winners"/><ref name="magriel"/> | ||
''Diversification'' refers to a complementary tactic of placing one's own | ''Diversification'' refers to a complementary tactic of placing one's own pieces in such a way that more numbers are useful.<ref name="magriel"/> | ||
The ''[[Pip (counting)#Dice|pipcount]]'' is number of pips needed to move a player's | The ''[[Pip (counting)#Dice|pipcount]]'' is number of pips needed to move a player's pieces around and off the board. Many positions require a measurement of a player's standing in the race, for example, in making a doubling cube decision, or in determining whether to run home and begin bearing off. The difference between the two players' pip counts is a measure of the leader's racing advantage. For cube decisions, a number of formulas have been developed over the years,<ref>{{Cite web |title=Backgammon Articles: When and How to Use the Doubling Cube |url=https://www.bkgm.com/articles/page04.html#pip_counting |access-date=2024-10-11 |website=www.bkgm.com}}</ref> including the Thorpe count,<ref>{{Cite web |title=Backgammon Cube Handling in Races |url=https://www.bkgm.com/rgb/rgb.cgi?view+772 |access-date=2024-10-11 |website=www.bkgm.com}}</ref> the Ward count, the Keith count,<ref>{{Cite web |title=Cube Handling in Noncontact Positions |url=https://www.bkgm.com/articles/CubeHandlingInRaces/#comparing_the_formulas |access-date=2024-10-11 |website=www.bkgm.com}}</ref> and iSight.<ref>{{Cite web |last=Reichert |first=Axel |date=2014-06-12 |title=Improved Cube Handling in Races: Insights with Isight |url=https://bkgm.com/articles/Reichert/insights-with-isight.pdf |website=bkgm.com}}</ref> These calculations enable a player to determine whether to offer or take a double based on the pipcount in non-contact positions. | ||
===Cube handling=== | ===Cube handling=== | ||
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* The ''live cube model'' assumes a maximum value for sole cube access (i.e. that the taker may use the cube most efficiently by either raising the stakes or doubling out the opponent). It estimates that the takepoint is 20% and the doubling window opens at 80%. | * The ''live cube model'' assumes a maximum value for sole cube access (i.e. that the taker may use the cube most efficiently by either raising the stakes or doubling out the opponent). It estimates that the takepoint is 20% and the doubling window opens at 80%. | ||
In practice, the takepoints and doubling points are somewhere in between, since while cube ownership cannot be ignored, assuming maximal efficiency for a re-cube is also not a valid assumption.<ref>https://www.bkgm.com/articles/Janowski/cubeformulae.pdf</ref> Ignoring gammons and backgammons, the takepoint in money play is about 22%.<ref>{{Cite web |title=GAMMONLIFE.COM - Backgammon Cube Strategy Made Simple |url=http://www.gammonlife.com/writers/simple-backgammon-cube-strategy.htm |access-date=2024-10-11 |website=www.gammonlife.com}}</ref> All of the above ignores gammons and backgammons for either side, so in practice the calculation of takepoints is more complicated.<ref>https://www.bkgm.com/articles/Simborg/WhenToDouble/index.html | In practice, the takepoints and doubling points are somewhere in between, since while cube ownership cannot be ignored, assuming maximal efficiency for a re-cube is also not a valid assumption.<ref>{{Cite web |last=Janowski |first=Rick |title=Take-Points in Money Games |url=https://www.bkgm.com/articles/Janowski/cubeformulae.pdf |website=www.bkgm.com}}</ref> Ignoring gammons and backgammons, the takepoint in money play is about 22%.<ref>{{Cite web |title=GAMMONLIFE.COM - Backgammon Cube Strategy Made Simple |url=http://www.gammonlife.com/writers/simple-backgammon-cube-strategy.htm |access-date=2024-10-11 |website=www.gammonlife.com}}</ref> All of the above ignores gammons and backgammons for either side, so in practice the calculation of takepoints is more complicated.<ref>{{Cite web |title=When to Double |url=https://www.bkgm.com/articles/Simborg/WhenToDouble/index.html |access-date=2025-08-02 |website=www.bkgm.com |quote=I wish there were as good a law for when to take the cube. No one I know has come up with a simple solution for this ...}}</ref> | ||
==Equity== | ==Equity== | ||
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:''Example 1'' | :''Example 1'' | ||
[[File:Bkgm61.jpg|thumb|upright=.7|right]] | [[File:Bkgm61.jpg|thumb|upright=.7|right]] | ||
:Suppose there are only two | :Suppose there are only two pieces left on the board and the player on-roll has a piece on their six point and the opponent has a piece on their one point. The player on-roll will bear off with 27/36 rolls or 75% of the time. If the game was played from that position 100 times the on-roll player would win ~75 games and their opponent would win ~25 for a net win of ~50 points per 100 games. The on-roll player's equity would be .5 and their opponent's would be −.5. | ||
:If the doubling cube was accessible they could offer the cube and increase their equity to 1: either their opponent passes the cube and the game is over, or their opponent takes the cube and loses 100 points per 100 games (instead of the 50 with the cube centered). This illustrates that the raw takepoint for money play is 25%. | :If the doubling cube was accessible they could offer the cube and increase their equity to 1: either their opponent passes the cube and the game is over, or their opponent takes the cube and loses 100 points per 100 games (instead of the 50 with the cube centered). This illustrates that the raw takepoint for money play is 25%. | ||
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:''Example 2'' | :''Example 2'' | ||
:Now, suppose the on-roll player has two | :Now, suppose the on-roll player has two pieces, one on the five point and one on the one point while their opponent still has one on the one point. 23 rolls bear off both pieces so the winning percentage is 64% instead of 75% and the equities are about +0.28 ((64−36)/100) and −0.28. If the on-roll player offers the cube, their equity doubles to 0.56 and their opponent should take the cube because −0.56 is better than −1. | ||
[[File:Bkgm5ptHoldingGame.jpg|thumb|upright=.7|right]] | [[File:Bkgm5ptHoldingGame.jpg|thumb|upright=.7|right]] | ||
:''Example 3'' | :''Example 3'' | ||
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== Social and competitive play == | == Social and competitive play == | ||
[[Image:Wurfzabel.jpg|thumb|Medieval players, from the 13th-century ''[[Carmina Burana]]'']] | [[Image:Wurfzabel.jpg|thumb|Medieval players of a tables game, from the 13th-century ''[[Carmina Burana]]'']] | ||
=== Legality === | === Legality === | ||
In ''State of Oregon v. Barr'', a 1982 court case pivotal to the continued widespread organised playing of backgammon in the US, the State argued that backgammon is a game of chance and that it was therefore subject to Oregon's stringent gambling laws. [[Paul Magriel]] was a key witness for the defence, contradicting Roger Nelson, the expert prosecution witness, by saying, "Game theory, however, really applies to games with imperfect knowledge, where something is concealed, such as poker. Backgammon is not such a game. Everything is in front of you. The person who uses that information in the most effective manner will win." After the closing arguments, Judge Stephen S. Walker concluded that backgammon is a game of skill, not a game of chance, and found the defendant, backgammon tournament director Ted Barr, not guilty of promoting gambling.<ref>{{cite news|newspaper=Backgammon Times|title=The Trial (and Tribulations) of Oregon Promoter Ted Barr|volume=2|issue=2|year=1982|url=http://www.bkgm.com/articles/BackgammonTimes/LuckVsSkill-TrialOfTedBarr/index.html}}</ref> | In ''State of Oregon v. Barr'', a 1982 court case pivotal to the continued widespread organised playing of backgammon in the US, the State argued that backgammon is a game of chance and that it was therefore subject to Oregon's stringent gambling laws. [[Paul Magriel]] was a key witness for the defence, contradicting Roger Nelson, the expert prosecution witness, by saying, "Game theory, however, really applies to games with imperfect knowledge, where something is concealed, such as poker. Backgammon is not such a game. Everything is in front of you. The person who uses that information in the most effective manner will win." After the closing arguments, Judge Stephen S. Walker concluded that backgammon is a [[game of skill]], not a game of chance, and found the defendant, backgammon tournament director Ted Barr, not guilty of promoting gambling.<ref>{{cite news|newspaper=Backgammon Times|title=The Trial (and Tribulations) of Oregon Promoter Ted Barr|volume=2|issue=2|year=1982|url=http://www.bkgm.com/articles/BackgammonTimes/LuckVsSkill-TrialOfTedBarr/index.html}}</ref> | ||
=== Club and tournament play === | === Club and tournament play === | ||
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A successful triangular backgammon tournament, devised by UKBGF,<ref>[https://ukbgf.com/2022-election-statements/ www.ukbgf.com]</ref> was hosted in 2025 by the [[Walbrook Club]] versus the [[Worshipful Company of Haberdashers|Haberdashers']] & [[Worshipful Company of Salters|Salters' Companies]]. | A successful triangular backgammon tournament, devised by UKBGF,<ref>[https://ukbgf.com/2022-election-statements/ www.ukbgf.com]</ref> was hosted in 2025 by the [[Walbrook Club]] versus the [[Worshipful Company of Haberdashers|Haberdashers']] & [[Worshipful Company of Salters|Salters' Companies]]. | ||
Following the 2025 pilot event, the 2026 UKBGF Clubs Championship was scheduled for July 25–26 at the [[University of Kent]] in [[Canterbury]]. The tournament expansion reflects a growing trend in the mid-2020s toward formalized "Inter-Club" play, utilizing digital registration and real-time rating systems to integrate regional clubs into a unified national competitive structure. <ref>{{Cite web |title=UKBGF Clubs Championship 2026 |url=https://www.eastkentbackgammonclub.com/ukbgf-club-championship-2026 |access-date=2026-05-04 |website=East Kent Backgammon |language=en}}</ref> | |||
=== International competition === | === International competition === | ||
{{See also|List of world backgammon champions}} | {{See also|List of world backgammon champions}} | ||
The first world championship competition in backgammon was held in Las Vegas, Nevada, in 1967. [[Tim Holland (backgammon)|Tim Holland]] was declared the winner that year and at the tournament the following year. For unknown reasons, there was no championship in 1970, but in 1971, Tim Holland again won the title. The competition remained in Las Vegas until 1975, when it moved to [[Paradise Island]] in the Bahamas. The years 1976, 1977 and 1978 saw "dual" World Championships, one in the Bahamas attended by the Americans, and the ''European Open Championships'' in Monte Carlo with mostly European players. In 1979, Lewis Deyong, who had promoted the Bahamas World Championship for the prior three years, suggested that the two events be combined.<ref name="PLAY65" | The first world championship competition in backgammon was held in Las Vegas, Nevada, in 1967. [[Tim Holland (backgammon)|Tim Holland]] was declared the winner that year and at the tournament the following year. For unknown reasons, there was no championship in 1970, but in 1971, Tim Holland again won the title. The competition remained in Las Vegas until 1975, when it moved to [[Paradise Island]] in the Bahamas. The years 1976, 1977 and 1978 saw "dual" World Championships, one in the Bahamas attended by the Americans, and the ''European Open Championships'' in Monte Carlo with mostly European players. In 1979, Lewis Deyong, who had promoted the Bahamas World Championship for the prior three years, suggested that the two events be combined.<ref name="PLAY65"/> Monte Carlo was universally acknowledged as the site of the World Backgammon Championship and has remained as such for thirty years.<ref name="mindzine">{{cite web|url=http://www.msoworld.com/mindzine/news/classic/bg/tournaments/world00report.html|title=Backgammon News—World Championships 2000|author=Michael Crane|publisher=Mind Sports Worldwide|date=July 25, 2000|access-date=2006-09-14|archive-url=https://web.archive.org/web/20060907014829/http://www.msoworld.com/mindzine/news/classic/bg/tournaments/world00report.html|archive-date=7 September 2006|url-status=dead}}</ref> The Monte Carlo tournament draws hundreds of players and spectators, and is played over the course of a week.<ref name="maxa"/> | ||
By the 21st century, the largest international tournaments had established the basis of a tour for top professional players. Major tournaments are held yearly worldwide. [[PartyGaming]] sponsored the first [[World Series of Backgammon]] in 2006 from [[Cannes]] and later the "Backgammon Million" tournament held in the Bahamas in January 2007 with a prize pool of one million dollars, the largest for any tournament to date.<ref name="partygammon">{{cite news|title=PartyGammon.com to Stage First Ever US$1 Million Backgammon Tournament|work=PR Newswire|date=July 10, 2006|publisher=[[Lexis-Nexis]]}}</ref> In 2008, the [[World Series of Backgammon]] ran the world's largest international events in London, the UK Masters, the biggest tournament ever held in the UK with 128 international class players; the Nordic Open, which instantly became the largest in the world with around 500 players in all flights and 153 in the championship, and Cannes, which hosted the Riviera Cup, the traditional follow-up tournament to the World Championships. Cannes also hosted the WSOB championship, the WSOB finale, which saw 16 players play three-point shootout matches for €160,000. The event was recorded for television in Europe and aired on [[Eurosport]]. | By the 21st century, the largest international tournaments had established the basis of a tour for top professional players. Major tournaments are held yearly worldwide. [[PartyGaming]] sponsored the first [[World Series of Backgammon]] in 2006 from [[Cannes]] and later the "Backgammon Million" tournament held in the Bahamas in January 2007 with a prize pool of one million dollars, the largest for any tournament to date.<ref name="partygammon">{{cite news|title=PartyGammon.com to Stage First Ever US$1 Million Backgammon Tournament|work=PR Newswire|date=July 10, 2006|publisher=[[Lexis-Nexis]]}}</ref> In 2008, the [[World Series of Backgammon]] ran the world's largest international events in London, the UK Masters, the biggest tournament ever held in the UK with 128 international class players; the Nordic Open, which instantly became the largest in the world with around 500 players in all flights and 153 in the championship, and Cannes, which hosted the Riviera Cup, the traditional follow-up tournament to the World Championships. Cannes also hosted the WSOB championship, the WSOB finale, which saw 16 players play three-point shootout matches for €160,000. The event was recorded for television in Europe and aired on [[Eurosport]]. | ||
The World Backgammon Association (WBA)<ref>{{cite web|url=http://www.world-backgammon-association.com|title=World Backgammon Association|website=www.world-backgammon-association.com}}</ref> has been holding the biggest backgammon tour on the circuit since 2007, the "European Backgammon Tour"<ref>{{cite web|url=http://www.ebgt.info/|title=Home|website=www.ebgt.info|access-date=2013-11-20|archive-date= | The World Backgammon Association (WBA)<ref>{{cite web|url=http://www.world-backgammon-association.com|title=World Backgammon Association|website=www.world-backgammon-association.com}}</ref> has been holding the biggest backgammon tour on the circuit since 2007, the "European Backgammon Tour"<ref>{{cite web|url=http://www.ebgt.info/|title=Home|website=www.ebgt.info|access-date=2013-11-20|archive-date=2010-12-30|archive-url=https://web.archive.org/web/20101230165744/http://www.ebgt.info/|url-status=dead}}</ref> (EBGT). In 2011, the WBA collaborated with the online backgammon provider Play65 for the 2011 season of the European Backgammon Tour and with "[[Betfair]]" in 2012. The 2013 season of the European Backgammon Tour featured 11 stops and 19 qualified players competing for €19,000 in a grand finale in [[Lefkosa]], Northern Cyprus. | ||
=== Gambling === | === Gambling === | ||
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== Mediterranean and West Asian cultural significance == | == Mediterranean and West Asian cultural significance == | ||
[[File:Damascene-style inlaid Backgammon board, Cairo, Khan el-Khalili.jpg|thumb|upright|[[Damascening|Damascene]]-style [[marquetry]] backgammon board, [[Khan el-Khalili]], Cairo]] | |||
Backgammon is considered the national game in many countries of the [[Eastern Mediterranean]]:<ref name="Arab American Almanac 1984">{{cite book |title=Arab American Almanac |publisher=News Circle Publishing Company |year=1984 |isbn=978-0-915652-03-7 |url=https://books.google.com/books?id=4j0OAQAAMAAJ |access-date=2022-05-03 |page=47|quote=Backgammon: Throughout the Eastern Mediterranean region, it is unquestionably the single most popular game ; tric trac or towleh (table), as it is called, is practically the national sport of Lebanon }}</ref> [[Egypt]],<ref name="Allatson Gallimard (Firm) 1995">{{cite book |last=Allatson |first=W. |author2=Gallimard (Firm) |title=Egypt |publisher=Alfred A. Knopf |series=Knopf Book and Cassette Classics Series |year=1995 |isbn=978-0-679-75566-1 |url=https://books.google.com/books?id=zh8ZAQAAIAAJ |access-date=2022-05-03 |page=495|quote=...''tawla'' (backgammon), the national game…}}</ref> [[Turkey]],<ref name="Ergil 2014">{{cite web |last=Ergil |first=Leyla Yvonne |title=Top Tavla tips for expats to play like a Turk |website=Daily Sabah |date=2014-10-11 |url=https://www.dailysabah.com/life/2014/10/11/top-tavla-tips-for-expats-to-play-like-a-turk |quote=Tavla, otherwise known as backgammon, can easily be considered Turkey's national game and, in the way it is played a metaphor for life in Turkey.}}</ref> [[Cyprus]],<ref name="Hinebaugh 2019">{{cite book |last=Hinebaugh |first=J.P. |title=More Board Game Education: Inspiring Students Through Board Games |publisher=Rowman & Littlefield Publishers |year=2019 |isbn=978-1-4758-4834-2 |url=https://books.google.com/books?id=GPd7DwAAQBAJ&pg=PA49 |access-date=2022-05-03 |page=49|quote=Tavli (Backgammon in Greek) is the national game of Cyprus}}</ref> [[Syria]],<ref name="Los Angeles Times 1988">{{cite web |title=Love of Backgammon : To Arabs, It's the 1 Game That Counts |website=Los Angeles Times |date=1988-02-04 |url=https://www.latimes.com/archives/la-xpm-1988-02-04-mn-40503-story.html |quote=While other games--chess, bridge, even poker--have made inroads from time to time, backgammon has been for centuries the pastime of the Middle East}}</ref> [[Israel]],<ref name="The Israel Economist 1978">{{cite book |title=The Israel Economist |publisher=Kollek. |issue=v. 33 |year=1978 |url=https://books.google.com/books?id=0WseAQAAMAAJ |access-date=2022-05-03 |quote=Even in Israel [Rummikub] took a long time to make an impact, though today it ranks only just behind Shesh-Besh (backgammon) as the national pastime }}</ref> [[Palestine]],<ref name="Khūrī Ḫūrī 1990">{{cite book |last1=Khūrī |first1=F.I. |last2=Ḫūrī |first2=F.I. |title=Tents and Pyramids: Games and Ideology in Arab Culture from Backgammon to Autocratic Rule |publisher=Saqi Books |year=1990 |isbn=978-0-86356-334-8 |url=https://books.google.com/books?id=N_SNAAAAMAAJ |access-date=2022-05-03}}</ref> [[Lebanon]]<ref name="Arab American Almanac 1984" /> and [[Greece]].<ref name="Team 2018">{{cite web |last=Team |first=GCT |title=All You Need To Know About Tavli, Greece's National Board Game |website=Greek City Times |date=2018-01-23 |url=https://greekcitytimes.com/2018/01/23/all-you-need-to-know-about-tavli-greeces-national-board-game/ |access-date=2022-05-02}}</ref> | |||
Backgammon is considered the national game in many countries of the Eastern Mediterranean:<ref name="Arab American Almanac 1984">{{cite book |title=Arab American Almanac |publisher=News Circle Publishing Company |year=1984 |isbn=978-0-915652-03-7 |url=https://books.google.com/books?id=4j0OAQAAMAAJ |access-date=2022-05-03 |page=47|quote=Backgammon: Throughout the Eastern Mediterranean region, it is unquestionably the single most popular game ; tric trac or towleh (table), as it is called, is practically the national sport of Lebanon }}</ref> Egypt,<ref name="Allatson Gallimard (Firm) 1995">{{cite book |last=Allatson |first=W. |author2=Gallimard (Firm) |title=Egypt |publisher=Alfred A. Knopf |series=Knopf Book and Cassette Classics Series |year=1995 |isbn=978-0-679-75566-1 |url=https://books.google.com/books?id=zh8ZAQAAIAAJ |access-date=2022-05-03 |page=495|quote=...''tawla'' (backgammon), the national game…}}</ref> Turkey,<ref name="Ergil 2014">{{cite web |last=Ergil |first=Leyla Yvonne |title=Top Tavla tips for expats to play like a Turk |website=Daily Sabah |date=2014-10-11 |url=https://www.dailysabah.com/life/2014/10/11/top-tavla-tips-for-expats-to-play-like-a-turk |quote=Tavla, otherwise known as backgammon, can easily be considered Turkey's national game and, in the way it is played a metaphor for life in Turkey.}}</ref> Cyprus,<ref name="Hinebaugh 2019">{{cite book |last=Hinebaugh |first=J.P. |title=More Board Game Education: Inspiring Students Through Board Games |publisher=Rowman & Littlefield Publishers |year=2019 |isbn=978-1-4758-4834-2 |url=https://books.google.com/books?id=GPd7DwAAQBAJ&pg=PA49 |access-date=2022-05-03 |page=49|quote=Tavli (Backgammon in Greek) is the national game of Cyprus}}</ref> Syria,<ref name="Los Angeles Times 1988">{{cite web |title=Love of Backgammon : To Arabs, It's the 1 Game That Counts |website=Los Angeles Times |date=1988-02-04 |url=https://www.latimes.com/archives/la-xpm-1988-02-04-mn-40503-story.html |quote=While other games--chess, bridge, even poker--have made inroads from time to time, backgammon has been for centuries the pastime of the Middle East}}</ref> Israel,<ref name="The Israel Economist 1978">{{cite book |title=The Israel Economist |publisher=Kollek. |issue=v. 33 |year=1978 |url=https://books.google.com/books?id=0WseAQAAMAAJ |access-date=2022-05-03 |quote=Even in Israel [Rummikub] took a long time to make an impact, though today it ranks only just behind Shesh-Besh (backgammon) as the national pastime }}</ref> | |||
The popularity of the game across the region is primarily an oral tradition,<ref name="Los Angeles Times 1988" /> and appears to have been strengthened during the era of the Ottoman Empire, which controlled the whole Eastern Mediterranean in the early modern period. [[Afif Bahnassi]], Syria's director of antiquities, stated in 1988: "For some reason, backgammon became the rage of the Ottoman Empire. It really spread across the Arab world with the Turks, and it stayed behind when they left."<ref name="Los Angeles Times 1988" /> The game is a common feature of coffeehouses throughout the region. Since at least the early 19th century, [[Damascus]] became well known as the preeminent location for [[Damascening|Damascene]]-style wooden [[marquetry]] backgammon sets that have become famous throughout the region.<ref name="Los Angeles Times 1988" /> | The popularity of the game across the region is primarily an oral tradition,<ref name="Los Angeles Times 1988" /> and appears to have been strengthened during the era of the [[Ottoman Empire]], which controlled the whole Eastern Mediterranean in the early modern period. Backgammon is also widely popular in [[Armenia]] and frequently played in public spaces.<ref>{{Cite journal |last=Fehlings |first=Susanne Helma Christiane |date=2015-07-07 |editor-last=Professor Carola Silvia Neugebauer and Lela Rekhviashvili |editor-first=Associate |title=Intimacy and exposure – the Armenian “tun” and Yerevan’s public space |url=http://www.emerald.com/ijssp/article/35/7-8/513-532/159399 |journal=International Journal of Sociology and Social Policy |language=en |volume=35 |issue=7/8 |pages=513–532 |doi=10.1108/IJSSP-02-2015-0028 |issn=0144-333X|url-access=subscription }}</ref> [[Afif Bahnassi]], Syria's director of antiquities, stated in 1988: "For some reason, backgammon became the rage of the Ottoman Empire. It really spread across the Arab world with the Turks, and it stayed behind when they left."<ref name="Los Angeles Times 1988" /> The game is a common feature of coffeehouses throughout the region. Since at least the early 19th century, [[Damascus]] became well known as the preeminent location for [[Damascening|Damascene]]-style wooden [[marquetry]] backgammon sets that have become famous throughout the region.<ref name="Los Angeles Times 1988" /> | ||
[[File:Backgammon and Dominos numbers in Ottoman Turkish, 1907.jpg|thumb|Backgammon and Dominos numbers in [[Ottoman Turkish]], in [[V. H. Hagopian]]'s 1907 ''Ottoman-Turkish Conversation-Grammar''. [[James Redhouse]]'s milestone [[Ottoman Turkish]] dictionary in the 19th century described a similar phenomenon alongside many other Ottoman words of Persian or Turkish origin.<ref name="Redhouse 1890">{{cite book |last=Redhouse |first=J.W. |authorlink=James Redhouse|title=A Turkish and English Lexicon: Shewing in English the Significations of the Turkish Terms |publisher=American mission |issue=pt. 2, pp. 1000-2224 |year=1890 |url=https://books.google.com/books?id=mms7AQAAMAAJ&pg=PA1436 |access-date=2022-05-01 |page=1125|quote=P. [for Persian origin]: شش shesh, a. Six. شش اناز A player with six objects. 2. A player at backgammon. شش بش Six and five, in backgammon. شش و يك Six and one. شش بش كورمك (To take the six for a five) To see double. دو شش Sixes, in backgammon}}</ref>]] | [[File:Backgammon and Dominos numbers in Ottoman Turkish, 1907.jpg|thumb|Backgammon and Dominos numbers in [[Ottoman Turkish]] of Persian origin, in [[V. H. Hagopian]]'s 1907 ''Ottoman-Turkish Conversation-Grammar''. [[James Redhouse]]'s milestone [[Ottoman Turkish]] dictionary in the 19th century described a similar phenomenon alongside many other Ottoman words of Persian or Turkish origin.<ref name="Redhouse 1890">{{cite book |last=Redhouse |first=J.W. |authorlink=James Redhouse|title=A Turkish and English Lexicon: Shewing in English the Significations of the Turkish Terms |publisher=American mission |issue=pt. 2, pp. 1000-2224 |year=1890 |url=https://books.google.com/books?id=mms7AQAAMAAJ&pg=PA1436 |access-date=2022-05-01 |page=1125|quote=P. [for Persian origin]: شش shesh, a. Six. شش اناز A player with six objects. 2. A player at backgammon. شش بش Six and five, in backgammon. شش و يك Six and one. شش بش كورمك (To take the six for a five) To see double. دو شش Sixes, in backgammon}}</ref>]] | ||
A unique feature of backgammon throughout the region is players' use of mixed Persian and Turkish numbers to announce dice rolls, rather than Arabic or other local languages.<ref name="Gippert">{{cite book |last=Gippert |first=Jost |url=https://books.google.com/books?id=YdwNAAAAYAAJ |title=XXIII. Deutscher Orientalistentag: vom 16. bis 20. September 1985 in Würzburg : ausgewählte Vorträge |publisher=F. Steiner Verlag Wiesbaden |year=1989 |isbn=978-3-515-04961-0 |editor=Einar von Schuler |series=Zeitschrift der Deutschen Morgenländischen Gesellschaft, Volume 139 (or Volume 7 of Zeitschrift der Deutschen Morgenländischen Gesellschaft: Supplement) |pages=259–273 |language=de |chapter=Ein persisch-türkisches Zählsystem beim Würfelspiel ["A Persian-Turkic counting system used in dice games"]}} This can be read online at [https://titus.fkidg1.uni-frankfurt.de/personal/jg/html/jg1985b.htm] ([https://web.archive.org/web/20020203231823/https://titus.fkidg1.uni-frankfurt.de/personal/jg/html/jg1985b.htm archived]</ref> Related to this phenomenon, the game is frequently referred to as ''Shesh Besh'', which is a rhyming combination ''shesh'', meaning ‘six’ in Persian (as well as many historical and current [[Iranian languages]]), and ''besh'', meaning five in Turkish. ''Shesh besh'' is commonly used to refer to when a player scores a 5 and 6 at the same time on dice.<ref name="BoueriBoutros2006">{{cite book |last1=Boueri |first1=Marijean |last2=Boutros |first2=Jill |last3=Sayad |first3=Joanne |title=Lebanon A to Z: A Middle Eastern Mosaic |url=https://books.google.com/books?id=VIemBhgNmpAC&pg=PA59 |publisher=PublishingWorks |date=April 2006 |pages=59– |isbn=978-0-9744803-4-3}}</ref> This language contains six types of [[irregular inflection]]s: | A unique feature of backgammon throughout the region is players' use of mixed Persian and Turkish numbers to announce dice rolls, rather than Arabic or other local languages.<ref name="Gippert">{{cite book |last=Gippert |first=Jost |url=https://books.google.com/books?id=YdwNAAAAYAAJ |title=XXIII. Deutscher Orientalistentag: vom 16. bis 20. September 1985 in Würzburg : ausgewählte Vorträge |publisher=F. Steiner Verlag Wiesbaden |year=1989 |isbn=978-3-515-04961-0 |editor=Einar von Schuler |series=Zeitschrift der Deutschen Morgenländischen Gesellschaft, Volume 139 (or Volume 7 of Zeitschrift der Deutschen Morgenländischen Gesellschaft: Supplement) |pages=259–273 |language=de |chapter=Ein persisch-türkisches Zählsystem beim Würfelspiel ["A Persian-Turkic counting system used in dice games"]}} This can be read online at [https://titus.fkidg1.uni-frankfurt.de/personal/jg/html/jg1985b.htm] ([https://web.archive.org/web/20020203231823/https://titus.fkidg1.uni-frankfurt.de/personal/jg/html/jg1985b.htm archived]</ref> Related to this phenomenon, the game is frequently referred to as ''Shesh Besh'', which is a rhyming combination ''shesh'', meaning ‘six’ in Persian (as well as many historical and current [[Iranian languages]]), and ''besh'', meaning five in Turkish. ''Shesh besh'' is commonly used to refer to when a player scores a 5 and 6 at the same time on dice.<ref name="BoueriBoutros2006">{{cite book |last1=Boueri |first1=Marijean |last2=Boutros |first2=Jill |last3=Sayad |first3=Joanne |title=Lebanon A to Z: A Middle Eastern Mosaic |url=https://books.google.com/books?id=VIemBhgNmpAC&pg=PA59 |publisher=PublishingWorks |date=April 2006 |pages=59– |isbn=978-0-9744803-4-3}}</ref> This language contains six types of [[irregular inflection]]s: | ||
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* 5) special cases (3–2, 2–2, 1–1); where 3–2 is a version of 2a with a "ba" added for phonetic reasons, 2–2 is {{langx|fa|دوباره}} for "twice" or two-times-two, and 1–1 is a hybrid Turkish-Persian where ''hep'' is Turkish for "altogether".<ref name=Gippert /> | * 5) special cases (3–2, 2–2, 1–1); where 3–2 is a version of 2a with a "ba" added for phonetic reasons, 2–2 is {{langx|fa|دوباره}} for "twice" or two-times-two, and 1–1 is a hybrid Turkish-Persian where ''hep'' is Turkish for "altogether".<ref name=Gippert /> | ||
In the early 20th century, as use of Classical Arabic was being promoted with the rise of Arab nationalism,{{where|date=July 2025}} efforts were made to replace the Persian-Turkish numbers used in backgammon play.<ref name="Suleiman 2013 p. 8">{{cite book |last=Suleiman |first=Y. |title=Arabic Sociolinguistics: Issues and Perspectives |publisher=Taylor & Francis |year=2013 |isbn=978-1-136-77937-4 |url=https://books.google.com/books?id=o8xdAgAAQBAJ&pg=PA8 |access-date=2022-05-01 |page=8}}</ref> | In the early 20th century, as use of Classical Arabic was being promoted with the rise of [[Arab nationalism]],{{where|date=July 2025}} efforts were made to replace the Persian-Turkish numbers used in backgammon play.<ref name="Suleiman 2013 p. 8">{{cite book |last=Suleiman |first=Y. |title=Arabic Sociolinguistics: Issues and Perspectives |publisher=Taylor & Francis |year=2013 |isbn=978-1-136-77937-4 |url=https://books.google.com/books?id=o8xdAgAAQBAJ&pg=PA8 |access-date=2022-05-01 |page=8}}</ref> | ||
{| class="wikitable mw-collapsible mw-collapsed" | {| class="wikitable mw-collapsible mw-collapsed" | ||
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[[Image:GNU bg screenshot.png|thumb|A screen shot of GNU Backgammon, showing an evaluation and rollout of possible moves]] | [[Image:GNU bg screenshot.png|thumb|A screen shot of GNU Backgammon, showing an evaluation and rollout of possible moves]] | ||
Neural network research has resulted in three modern [[Proprietary software|proprietary programs]], JellyFish,<ref>{{cite web|url=http://www.backgammon.help/software.html|title=Backgammon software - Backgammon Online Guide|website=www.backgammon.help|access-date=2015-08-10|archive-url=https://web.archive.org/web/20150816163340/http://www.backgammon.help/software.html|archive-date=2015-08-16|url-status=dead}}</ref> Snowie<ref>{{cite web|url=http://www.bgsnowie.com|title=BackgammonSnowie - | Neural network research has resulted in three modern [[Proprietary software|proprietary programs]], JellyFish,<ref>{{cite web|url=http://www.backgammon.help/software.html|title=Backgammon software - Backgammon Online Guide|website=www.backgammon.help|access-date=2015-08-10|archive-url=https://web.archive.org/web/20150816163340/http://www.backgammon.help/software.html|archive-date=2015-08-16|url-status=dead}}</ref> Snowie<ref>{{cite web|url=http://www.bgsnowie.com|title=BackgammonSnowie - AI Training Backgammon Software|website=www.bgsnowie.com|archive-url=https://web.archive.org/web/20240318183620/http://www.bgsnowie.com/|archive-date=2024-03-18|url-status=dead}}</ref> and [[eXtreme Gammon]],<ref>{{cite web|url=http://www.extremegammon.com|title=eXtreme Gammon|website=www.extremegammon.com}}</ref> as well as the [[shareware]] BGBlitz<ref>{{cite web|url=http://www.bgblitz.com|title=BGBlitz|publisher=BGBlitz|access-date=2009-02-26|archive-url=https://web.archive.org/web/20090225122525/http://bgblitz.com/|archive-date=25 February 2009|url-status=live}}</ref> and the [[free software]] GNU Backgammon.<ref>{{Cite web|title=GNU Backgammon|url=https://www.gnu.org/software/gnubg/gnubg.html|access-date=2022-12-29|website=www.gnu.org}}</ref> JellyFish and Snowie are no longer actively developed or maintained, while eXtreme Gammon, BGBlitz, and GNU Backgammon remain in active use. These programs not only play the game, but offer tools for analyzing games and detailed comparisons of individual moves. The strength of these programs lies in their neural networks' weight tables, which are the result of extensive training. Without them, these programs play no better than a human novice. For the bearoff phase, backgammon software usually relies on a database containing precomputed equities for all possible bearoff positions. There are 54,263 bearoff positions for each side. This means there are 54,263<sup>2</sup> total bearoff positions (approximately 3 billion positions). In 1981 Hugh Sconyers wrote a computer program that solved all positions with nine pieces or fewer for both sides. In the early 1990s Hugh extended his results to all bearoff positions. For each position there are four results: no cube, roller's cube, center cube and opponent's cube. Thus, Hugh's bearoff database contains the exact answers to approximately 12 billion bearoff situations. | ||
Another neural network software developed by Nikolaos Papachristou is Palamedes that was developed in the early 2000s and it can also play variations like Hypergammon, Portes, Plakoto, Fevga, Narde and has multiple engines for each one.<ref>{{Cite web|title=Palamedes |url=https://nikpapa.com/Palamedes/}}</ref> | Another neural network software developed by Nikolaos Papachristou is Palamedes that was developed in the early 2000s and it can also play variations like Hypergammon, Portes, Plakoto, Fevga, Narde and has multiple engines for each one.<ref>{{Cite web|title=Palamedes |url=https://nikpapa.com/Palamedes/}}</ref> | ||