Backgammon Dictionary

Mobility.

[Verb.]  To throw a pair of dice.

[Noun.]  Two thrown dice, each showing a number from 1 to 6.

To make a new point at the leading edge of a prime using checkers from the rear of the prime. Usually the easiest way to roll a prime forward is to slot the point immediately in front of the prime.

To analyze a position by playing it out over and over again.

To estimate the equity of a position by means of computer simulation; see rollout.

An estimate of the equity of a position obtained through computer simulation. A rollout consists of numerous trials, the results of which are averaged together. See post by Gregg Cattanach.  See also: Truncated Rollout, Cubeless Rollout, Cubeful Rollout, Random Error, and Systematic Error.

A backgammon variant in which players have a once-per-game option of rerolling their own dice or asking for a reroll of the opponent's dice.  See: How to Play Roll-Over.

Bar.

[Because you "root" for your opponent to roll one.]  A dice roll that forces a position to collapse.

A period in a tournament during which each contestant (except those who received a bye) plays another contestant. For example, each round of an elimination tournament eliminates half the players.

A tournament format in which every contestant plays every other contestant in turn. The number of rounds required is one less than the number of contestants.  Compare: Elimination Format.

To escape a runner from the opponent's home board and it advance toward home as quickly as possible.

One of the two checkers that began the game on the opponent's one-point.

Any checker on the bar or in the opponent's home board.

The strategy employed by a player who is ahead in the race and tries to bring his checkers home and bear them off with as little interaction with the opponent as possible.

The stage of a backgammon game which begins when contact with the opponent is broken; a pure race.

A backgammon variant in which all checkers start off the board, and both players enter in the same quadrant, move around the board (1) in the same direction, and bear off from the same quadrant.  See: How to Play Russian Backgammon.

Free from danger of being hit.

See: Magriel's Safe-Bold Criteria.

A play that leaves no blots, or a play that leaves blots only in positions where the opponent is unlikely to hit.  Compare: Bold Play.

Move a checker out of danger of being hit.

Cover a blot or move it out of range of being hit.

To conceal or misrepresent your true ability.

To enter a tournament division below your skill level.