# odds

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odds
a statement of the probabilities that an event will or will not happen. If the probability is a/(a + b) that the event will happen and b/(a + b) that it will not happen, then the odds are a-b (or a to b, or a:b) in favor of the event and b-a (or b to a, or b:a) against the event. In the division of the probability into a + b parts the values of a and b are usually chosen so that both numbers are small whole numbers with the smaller number equal to 1 if possible. Generally the odds are stated in whichever form puts the larger number first, and in many cases this will be the odds against the event. Thus 4-1 odds on a horse in a horse race can be viewed as an estimate that the probability of the horse's winning is 1/5.
In some cases, odds are used to express probabilities explicitly: for example, if a geologist says that the odds are 5-1 against a volcano erupting this year, that is an estimate that the probability of an eruption is about 1/6. In betting situations, odds are at least a rough estimate for probabilities, but what they actually establish is the payoff ratio: if an event has a-b odds, then you must bet b in order to receive a + b if the event happens. Thus the odds can be viewed as the ratio of potential profit a to wager b. This traditional use of the word "odd" is believed to come from the old English word ord for a spear point, hence something hazardous.

Dictionary of units of measurement. 2015.

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• odds — S3 [ɔdz US a:dz] n [plural] ▬▬▬▬▬▬▬ 1¦(probability)¦ 2¦(difficulties)¦ 3 be at odds 4¦(horse racing etc)¦ 5 it makes no odds 6 pay over the odds ▬▬▬▬▬▬▬ 1.) ¦(PROBABILITY)¦ the odds how lik …   Dictionary of contemporary English

• odds — [ɒdz ǁ ɑːdz] noun [plural] 1. the odds how likely it is that something will happen: • The odds of us achieving our sales targets are very poor. • The odds are (= it is likely that ) selling will continue. 2. difficulties that make a good result… …   Financial and business terms

• Odds — stellen in der Wahrscheinlichkeitstheorie und Statistik eine Möglichkeit dar, Wahrscheinlichkeiten anzugeben. Beispielsweise spricht man von einer 1:1 Chance, dass bei einem Münzwurf Kopf erscheint. Mathematisch berechnen sich Odds als Quotienten …   Deutsch Wikipedia

• Odds — ([o^]dz), n. sing. & pl. [See {Odd}, a.] 1. Difference in favor of one and against another; excess of one of two things or numbers over the other; inequality; advantage; superiority; hence, excess of chances; probability. The odds are often… …   The Collaborative International Dictionary of English

• odds — [ adz ] noun plural ** 1. ) the chances of something happening: the odds of doing something: The odds of getting hit by a falling satellite are very small. (the) odds are (that) (=it is likely that): The odds are they won t succeed. the odds are… …   Usage of the words and phrases in modern English

• odds — ► PLURAL NOUN 1) the ratio between the amounts staked by the parties to a bet, based on the expected probability either way. 2) (the odds) the chances of something happening or being the case. 3) (the odds) the balance of advantage; superiority… …   English terms dictionary

• odds — [ädz] pl.n. [sometimes, esp. formerly, with sing. v.] 1. Archaic inequalities 2. Now Rare difference or amount of difference 3. difference in favor of one side over the other; advantage 4. an equalizing advantage given or received in betting,… …   English World dictionary

• odds-on — UK US adjective ► thought most likely to happen, succeed, or do a particular thing: odds on to do sth »He is odds on to serve another term as president of the Commission. odds on for sth »Next month looks odds on for a further rise in interest… …   Financial and business terms

• odds-on — adj 1.) odds on favourite the person, horse etc that is most likely to win a race or other competition 2.) BrE informal very likely it s odds on (that) ▪ It s odds on that she won t come. be odds on to do sth ▪ They must have felt they were odds… …   Dictionary of contemporary English

• odds-on — adjective INFORMAL very likely: it is odds on (that): It s odds on that Gerry will miss the meeting again. be odds on to do something: Pearson is odds on to play his last game on Saturday. the odds on favorite the person or animal that people… …   Usage of the words and phrases in modern English

• Odds On —   First edition cover Author(s) …   Wikipedia