A designation for certain significant stakes races for three-year-old fillies. An example is the Epsom Oaks.


Odds are values that express the probability of particular outcomes occurring, in relation to the probability that they won't occur.

odds against

The term ‘odds against’ means that the a bet on a selection has a less than even, or 1/1, chance of winning.
Odds against

odds compiler

A bookmaker or other individual who sets the odds for competitors.

odds on

The term ‘odds on’ means that a bet on a selection in a betting market has a better than even, or 1/1, chance of winning.
Odds on

off the board

1. An event for which a bookmaker isn't accepting bets. 2. In pari-mutuel betting, a horse with odds longer than 99 to 1.

off-course bookmaker

A bookmaker not physically present on a racecourse or at an event. For example, off-course bookmakers may operate via telephone or the internet.

off-shore bookmaker

A bookmaker located outside the country where the bet is being placed.

off-track betting

Betting at locations other than the racetrack - for example via the internet.

official rating

Abbreviated as OR, a value assigned to a horse based on its form. It's used to determine the weight to be carried by the horse in handicap races. In the UK, official ratings are assigned by the British Horseracing Authority.

on the bit

An expression meaning that a horse doesn't need riding from the jockey.

on-course bookmaker

A bookmaker physically present at a racecourse or event.


Abbreviation for over/under.

outright betting

In outright betting a bet is placed on the result of a sports tournament instead of on a single game or match in that tournament. Outright bets can be placed before or after a tournament starts. Winning bets are only paid out once the tournament has produced a winner.
Outright betting


A competitor considered unlikely to win an event, as reflected in long (high) odds. The opposite of a favourite.


A term describing a book with a negative profit margin for a bookmaker. In this situation, punters who backed every selection in the book would have returns greater than the total value of their stakes.


Abbreviated as OU, a bet that the total combined points, runs, or goals of both teams in a game will be either higher or lower than a specified combined score. In football, for example, over/under goals bets are popular.

over/under goals bet

An over/under goals bet is a bet on whether the total number of goals scored in a match will be higher or lower than the goal total specified in your bet.
Over/under goals betting


A betting situation in which the potential return is greater than the risk due to odds being inaccurately high.

overnight race

A horse race that's not a stakes race.


A bookmaker's profit margin, which is built into the bookmaker's odds for an event.