# “O” Backgammon Terms

## Terms that Start with “O” Letter

There are - 28 - terms.

### Odds

The ratio of the probability of an event happening to that of its not happening, or vice versa. Usually the higher number is given first. For example, the odds of rolling double 6's are "35 to 1 against".

### Off (the Board)

Said of checkers which have been borne off.

### One-Checker Model

A model for estimating winning chances in a pure race based on the players' pip counts. In this model, all of a player's pips are represented by just one checker on a infinitely-long backgammon board. The one-checker model overestimates winning chances in positions where one side has more wastage than the other. See post by: Hugh Sconyers.

### One-Point

The deepest point (1) in a player's home board, the point farthest from the bar and closest to being borne off; also called the ace-point.

### One-Point Match

A backgammon variant where the goal is to be the first player to bear off all of your checkers. There is no doubling cube and no bonus for gammons or backgammons (2). Since you never lose more than one point (4), back games are more of an option in this variant than in regular backgammon. See posts by Lou Poppler and Bernhard Kaiser.

### One-Sided Bearoff Database

A bearoff database where the arrangement of checkers on only one player's side is considered. The values in the database are calculated assuming the goal at each turn is to minimize the average number of rolls required to bear offCompare: Two-Sided Bearoff Database.

### Online Backgammon

This refers to playing backgammon over the Internet. Online backgammon allows players all over the world to compete against one another. You can play for rating points or for real money.  See: Backgammon Server.

### On Roll

The player whose turn it is. You are on roll as soon as your opponent picks up his dice to end his turn, and before you throw the dice to begin your own turn. For example, the only time you may double is when you are on roll.

### On the Bar

Where a checker is placed after it is hit. When you have a checker on the bar, you may not move any of your other checkers until that checker has been entered back onto the board.

### Open Division

The main division of a tournament; the division that any player may enter. Also called the championship division, it generally has the highest entry fee, the largest prizes, and attracts the strongest players.  Compare: Novice Division and Intermediate Division.

### Opening Game

The first phase of a backgammon game where the players have yet to establish their initial game plans.   Compare: Middle Game and End Game.

### Opening Roll

The first roll of the game in which both players simultaneously roll one die. This roll determines both the player to go first and the numbers that player must play.

### Open Point

A position on the board not occupied by two or more of the opponent's checkers.

### Open Tournament

A tournament open to any player regardless of strength or experience.  See: Open Division.

### Otter

[Another furry rodent, by analogy to beaver and raccoon.]  An immediate redouble (while retaining ownership of the cube) by the player who just accepted a raccoon.

### Outer Board

The side of the board away from where the players bear off their checkers. Each player's outer board comprises that player's points seven through twelve.  Compare: Home Board.