Backgammon

== Overview ==
Backgammon is one of the oldest board games known. It is a two player game where playing pieces are moved according to the roll of dice, and a player wins by removing all of his pieces from the board before their opponent. Backgammon is a member of the tables family, one of the oldest classes of board games in the world.
Backgammon involves a combination of strategy and luck (from rolling dice). While the dice may determine the outcome of a single game, over a series of many games, the better player will accumulate the better record, somewhat like poker. Thus, records of matches between players are good indicators of relative skill.[1] With each roll of the dice, players must choose from numerous options for moving their checkers and anticipate possible counter-moves by the opponent. In variants that originate from early 20th century New York, players may raise the stakes during the game. There is an established repertoire of common tactics and occurrences.
Like chess, backgammon has been studied with great interest by computer scientists. Owing to this research, backgammon software has been developed that is capable of beating world-class human players (see TD-Gammon for an example).
== History ==
=== Roman and Byzantine Empire ===
Tάβλη (tabula) meaning "table" or "board" in Byzantine Greek, is the oldest game with rules known to be nearly identical to backgammon; it is described in an epigram of Byzantine Emperor Zeno (AD 476–491).  The board was the same with 24 points, 12 on each side. As today, each player had 15 checkers and used cubical dice with sides numbered one to six.  The object of the game, to be the first to bear off all of one's checkers, was also the same.  Hitting a blot, reentering a piece from the bar, and bearing off, all followed the modern rules. The only differences with modern backgammon were the use of an extra die (three rather than two) and the starting of all pieces off the board (with them entering in the same way that pieces on the bar enter in modern backgammon).  The name τάβλη is still used for backgammon in Greece, where it is frequently played in town plateias and cafes.
The epigram of Zeno describes a particularly bad dice roll the emperor had for his given position. Zeno, who was white, had a stack of seven checkers, three stacks of two checkers and two blots, checkers that stand alone on a point and are therefore in danger of being put outside the board by an incoming opponent checker. Zeno threw the three dice with which the game was played and obtained 2, 5 and 6. As in backgammon, Zeno could not move to a space occupied by two opponent (black) pieces. The white and black checkers were so distributed on the points that the only way to use all of the three results, as required by the game rules, was to break the three stacks of two checkers into blots, exposing them and ruining the game for Zeno.
The τάβλη of Zeno's time is believed to be a direct descendant of the earlier Roman Ludus duodecim scriptorum ("Game of twelve lines") with that board's middle row of points removed, and only the two outer rows remaining.  Ludus duodecim scriptorum used a board with three rows of 12 points each with the 15 checkers being moved in opposing directions by the two players across three rows according to the roll of the three cubical dice.  Little specific text about the gameplay of Ludus duodecim scriptorum has survived; it may have been related to the older Ancient Greek dice game Kubeia. The earliest known mention of the game is in Ovid's Ars Amatoria (The Art of Love) (written between 1 BC and 8 AD).
=== Egypt and Iraq ===
Race board games involving dice have existed for millennia in the Near East and eastern Mediterranean, including the game senet of Ancient Egypt and theRoyal Game of Ur in Babylon. The ancient Egyptian game senet was excavated, along with illustrations, from Egyptian royal tombs dating to 3500 BC. Though using a board that is quite different from backgammon, it may be a predecessor. The Royal Game of Ur, originating in ancient Mesopotamia before 2600 BC, may also be an ancestor of modern-day table games like backgammon. It used tetrahedral dice. In the modern Middle East, backgammon is a common feature of coffeehouses.
=== Persia (Iran) ===
Excavations at Shahr-e Sukhteh (Persian شهر سوخته, literally "The Burnt City") in Iran have shown that a board race game existed there around 3000 BC. The artifacts include two dice and 60 checkers, and the set is believed to be 100 to 200 years older than the Royal Game of Ur. On the board found at Shahr-e Sukhteh the fields are fashioned by the coils of a snake.
Touraj Daryaee (2006)—on the subject of the first written mention of early precursors of backgammon—writes:
In the 11th century Shahnameh, the Persian poet Ferdowsi credits Burzoe with the invention of the tables game nard in the 6th century. He describes an encounter between Burzoe and a Rajavisiting from India. The Raja introduces the game of chess, and Burzoe demonstrates nard, played with dice made from ivory and teak. Today, Nard is the name for the Persian version of backgammon, which has different initial positions and objectives.  H. J. R. Murray details many versions of backgammon; modern Nard is noted there as being the same as backgammon and maybe dating back to 300–500 AD in the Babylonian Talmud,  although others believe the Talmud references the Greek race game Kubeia.
=== Turkey ===
Women playing tavla in southern Turkey.
Backgammon, which is known as "tavla", from Byzantine Greek τάβλη, is still a very popular game in Turkey, and it is customary to name the dice rolls with their Persian number names: yek (1), dü (2), se (3), chahar (4), pange (5), sheesh (6).
There are many variants of tavla in Turkey, where the course of play changes drastically. The usual tavla is also known as erkek tavlası meaning boys' or men's tavla. The other variant kız tavlası (meaning girls' tavla) is a game that depends only on the dice and involves no strategy. There is another variant called asker tavlası (meaning soldiers' tavla) where the pieces are thrown to the board randomly and the opponents try to flip their pieces over the opponents' pieces to beat them.
The usual Tavla rules are same as in the other neighboring Arab countries and Greece, as established over a millennium ago.
=== Greece ===
Backgammon is popular among Greeks. It is a game in which Greeks usually tease their opponent and they create a lively atmosphere. The game is called "Tavli", derived in Byzantine times from the Latin word "tabula".  A game, almost identical to backgammon, called Tavli (Byzantine Greek: τάβλη) is described in an epigram of the Byzantine Emperor Zeno (AD 476–481). There are four games of Tavli commonly played:
*Portes: Set-up and rules the same as backgammon, except that backgammons count as gammons (2 points) and there is no doubling cube.
*Plakoto: A game where one checker can trap another checker on the same point.
*Fevga: A game where one checker by itself can block a point.
*Asodio: Also known as Acey-deucey where all checkers are off the board, and you enter by rolling either doubles or acey-deucey.
These games are played one after another, in matches of three, five, or seven points. Before starting a match, each player rolls 1 die, and the player with the highest roll picks up both dice and re-rolls (i.e. it is possible to roll doubles for the opening move). Players use the same pair of dice in turns. After the first game, the winner of the previous game starts first. Each game counts as 1 point, if the opponent has borne off at least 1 stone, otherwise 2 points (gammon/backgammon). There is no doubling cube.
=== East Asia ===
Backgammon set from around the 10th century,China
Backgammon was popular in China for a time and was known as "shuanglu" (双陆), with the book Pǔ Shuāng (譜雙) written during the Southern Song(1127–1279) period recording over ten variants - but over time it was replaced by other games such as xiangqi (Chinese chess).
In Japan ban-sugoroku is thought to have been introduced from China in the sixth century. As a gambling game it was made illegal several times.  In the early Edo-era, a new and quick gambling game called Chō-han appeared and sugoroku quickly dwindled. By the 13th century the board game Go, originally played only by the aristocracy, had become popular among the general public.
=== Western Europe ===
The jeux de tables (Games of Tables), predecessors of modern backgammon, first appeared in France during the 11th Century and became a favorite pastime of gamblers. In 1254, Louis IX issued a decree prohibiting his court officials and subjects from playing. Tables games 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 extensive discussion of chess.  By the 17th Century, tables games had spread to Sweden. A wooden board and checkers were recovered from the wreck of theVasa among the belongings of the ship's officers. Backgammon appears widely in paintings of this period, mainly those of Dutch and German painters (Van Ostade, Jan Steen, Hieronymus Bosch, Bruegel and others). Some surviving artworks are "Cardsharps" by Caravaggio (the backgammon board is in the lower left) and "The Triumph of Death" by Pieter Bruegel the Elder (the backgammon board is in the lower right). Others are the Hell of Bosch and interior of an Inn by Jan Steen.
=== Great Britain ===
In the sixteenth century, Elizabethan laws and church regulations prohibited playing tables, but by the eighteenth century backgammon was popular among the English clergy.  Edmund Hoyle published A Short Treatise on the Game of Back-Gammon in 1743; this described rules and strategy for the game and was bound together with a similar text on whist.
In English, the word "backgammon" is most likely derived from "back" and Middle English "gamen", meaning "game" or "play". The earliest use documented by the Oxford English Dictionary was in 1650.
=== United States ===
The most recent major development in backgammon was the addition of the doubling cube. It was first introduced in the 1920s in New York City among members of gaming clubs in the Lower East Side.  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.
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".  "Obe", as he was called by friends, co-founded the International Backgammon Association,[65] 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;[64] stockbrokers and bankers began playing at conservative men's clubs.  People young and old all across the country dusted off their boards and checkers. Cigarette, liquor and car companies began to sponsor tournaments and Hugh Hefner held backgammon parties at the Playboy Mansion.  Backgammon clubs were formed and tournaments were held, resulting in a World Championship promoted in Las Vegas in 1967.
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 a Standards of Ethical Practice to address issues on which tournament rules fail to touch.
== How to Play ==
=== Equipment ===
The game of Backgammon is played on a specially designed board consisting of four tables of six thin triangles or points on each table.  The points start from the edges of the board nearest the players and are directed inwards so that they form two rows of 12 points opposite each other.  A bar bisects the board and the two tables on one side are designated the "inner tables" or "home tables", the others being referred to as the "outer tables".  Traditionally, the inner tables should be positioned facing the greatest light source.  There are fifteen white disks, fifteen black disks, two dice, two dice shakers and a doubling cube.  The doubling cube is a die having the numbers 2, 4, 8, 16, 32 and 64 inscribed upon its 6 faces. 
=== Preparation and Objective ===
Each player attempts to move all his pieces into the inner table nearest to him (his home table) and once that is achieved, to move or "bear" the pieces off the board.  The first player to do this wins.  However, that is only half the story because backgammon is not being played properly unless it is being played for stakes.  So the ultimate objective of a Backgammon match is to win more stakes than the opponent.   
=== Starting ===
Pieces can only move in one direction - from the opponent's inner table through the opponent's outer table, back through the player's outer table and finishing in the player's inner table.  White pieces move in a clockwise direction, Black moves in an anti-clockwise direction.  Since the inner tables point towards the light, it should therefore be clear who sits where.
For the purposes of describing the starting position, the points will be numbered1 to 12 on either side of the board starting with the first square of the inner table and finishing with the last square of the outer table.  On Black's side, position 2 white pieces on point 1, 5 black pieces on square 6, 3 black pieces on square 8 and five white pieces on square 12.  White's side should mirror this arrangement exactly.
Although Backgammon is played for stakes, this does not necessarily mean money - one can use counters, beans or one can just keep a score with pen and paper.  However, the gambling element can be eliminated completely by following the normal rules and merely ignoring the doubling cube and the stakes.  Normally, however, a stake is decided up front be it monetary or otherwise.
To begin, each player rolls one die each at the same time.  If a double is rolled, then the stake is doubled and both players roll again.  This is repeated until one player rolls a higher number than the other.  The player with the highest throw then uses the dice throw from both players to take the first turn and also chooses to play white or black (and thus which side to sit).
=== Doubling and stakes ===
At any time after the first turn, either player can offer to double the stakes prior to casting the dice.  Upon being presented with such an ultimatum, the other player must choose either to forfeit the game and the current stake or accept the offer. 
Once the stake has been doubled once in this way, only the player who accepted the most recent offer to double the stake can offer to re-double it.  Whenever this happens, the other player either forfeits the game or accepts the double and the opportunity to offer the next double.
The doubling cube is used to record the current amount of the stake.
=== Basic Play ===
Each turn consists of the opportunity to move counters towards the player's inner table according to the roll of the two dice.   Unless a double is thrown, two moves are allowed, one for each number on the dice.  When a double is thrown, four moves are allowed of the number on the dice.  Players are not allowed to pass on their moves - as many moves as possible must be made each turn.
* A point with two or more pieces of the same colour on it is safe - the opponent cannot land a piece on such a point..
* A point hosting only one piece is called a "blot".  Such a piece is vulnerable - if the opponent lands on this point the piece is captured and moved to the bar (this means physically placed on the middle bar dividing the board). 
* Captured pieces are re-entered on the furthest point from the player's inner table.   A throw of 1 allows the piece to move from the bar to point one of the opponent's inner table.  A throw of 5 allows the piece to enter at point 5 of the opponent's inner table.
* If a player has one or more pieces on the bar, no other pieces can be moved until all such pieces have re-entered play.  So if the dice throw and position of enemy pieces prevents a player from re-entering a piece onto the board from the bar, the player cannot move any other piece and play passes to the opponent.
A point hosting two or more of the opponent's pieces is said to be "blocked".   If six points in a row are blocked, the opponent is said to have formed a "prime".  This is a highly advantageous achievement because a prime cannot be traversed by an opponent but is completely free to be traversed by the player who created it.
=== Bearing Off ===
Once all pieces are present in a player's inner table, that player can start "bearing off".  A throw of 1 allows a player to bear off a piece from point 1 of his inner table, a throw of 2 allows a player to bear off a piece from point 2 of his inner table and so on.  Pieces borne off are simply removed from the board.   Player's do not have to bear off - if available, they can choose to move a piece within their inner table instead.  This is often done to pair up singlets in order to prevent them from capture.
When a player rolls a number that is higher than the highest point of the inner table upon which that player has pieces, the player is allowed to bear off the next highest piece.  For example, with a roll of double 5, if the player has a piece on point 5, two pieces on point 3, one piece on point 2 and one piece on point 1, the player would bear off the four highest placed pieces and be left with just one piece on point 1.
If after starting to bear off, a player's piece is captured, that piece must re-enter at the other side of the board and bearing off cannot re-start until all pieces are once again residing in the inner table.
=== Finishing ===
The first player to bear off all pieces wins the game. 
* If the opponent has borne off at least one piece, a single game is won and the current stake is forfeited. 
* If the opponent has not borne off any pieces, this is a "gammon" and worth double the current stake. 
* If the opponent has a piece left on the bar or within the opponent's inner table, this is a "backgammon" and worth triple the current stake.
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== Variations ==
=== Dutch Backgammon ===
This is played in the same way as Backgammon with only 2 differences:
* All the pieces start off the board "in hand" and all 15 must be entered on the opponent's inner table before any can proceed further
* A player cannot take an opponent's piece until at least one of his pieces has been moved into his inner (bearing) table.
=== Acey Deucey ===
This gambling game is popular with the US military forces and is similar to Dutch Backgammon - the keynote feature is that a throw of a 1 and a 2 is a special throw called "acey deucey".  It is played in the same way as backgammon with the following rule differences:
* At the beginning, the player who starts also chooses which table to enter and the opposing player must enter on the opposite table and travel in the opposite direction.  This, of course, is a purely cosmetic modification to the rules and does not affect the outcome of the game at all.
* All pieces start off the board "in hand".
* It isn't necessary for all pieces to be entered before any other piece can move. This applies at the beginning and during the game.
* A player throwing an acey deucey first moves a 1 and a 2 in the normal way.  Then the player chooses a double from 1 to 6 and moves again, exactly as if that double had been thrown.  e.g. if the player selects double five, that player makes 4 moves of 5 each.  Finally, the player is entitled to another throw of the dice, effectively a new turn.  However, if a player is not able to move both the initial 1 and 2, then the turns stops immediately and the double and the extra throw are forfeited.  Similarly, if all four moves that constitute the double cannot be taken, the ensuing extra throw is forfeited.
* Doubling is not part of Acey Deucey and there is no doubling cube.  However, some people play that the stake is doubled each time an acey-deucey is thrown.
* Acey Deucey also has a different method to determine the winnings each game. At the end of the game, the losing player must pay the winning player the stake times the number of pieces still remaining on the board.
== Links and References ==
Backgammon Rules
How to Play - wikiHow
BoardGameGeek Review