How betting odds work: what they are and how to use them
Fractions were traditionally used to bet on horse racing and were most popular in high street betting shops in the UK, before the advent of internet gambling. Betting odds are usually expressed either as fractions (e.g. ‘3/1’) or as decimals (e.g. 4.0). All of these have different possibilities, probabilities, chances – or odds – of happening. They give you a quick indication of how much you could expect to win if your bet wins.
However, not all fractional odds are traditionally read using the lowest common denominator (i.e. simplifying the fraction when possible). In either case, having won, the bettor always receives the original stake back too; so if the odds are 4/1 the bettor receives a total of £500 (£400 plus the original £100). Favoured by bookmakers in the United Kingdom and Ireland, and also common in horse racing, fractional odds quote the net profit that will be paid out to the bettor, should they win, relative to the stake. That value may be regarded as the relative probability the event will happen, expressed as a fraction (if it is less than 1), or a multiple (if it is equal to or greater than one) of the likelihood that the event will not happen. The odds are a ratio of probabilities; an odds ratio is a ratio of odds, that is, a ratio of ratios of probabilities.
Major sportsbooks now operate nationwide, often adjusting their lines independently or using odds from other sources, not just Las Vegas. For decades, Vegas was seen as the gold standard for odds-setting, with casinos along the Strip acting as trendsetters for the broader betting market. Sharp action – bets placed by professional or experienced bettors – also triggers line movement. When a large number of casual bettors, often called “public” bettors, place money on one side, the line may shift to reflect this surge in interest.
Void/cashed out bets excluded. Place a first qualifying £10 bet at EVS (2.0) or greater using cash balance. This code is for marketing and tracking purposes only. He is an NCTJ-qualified sports journalist who has accumulated over 10 years of experience in the sports betting industry. Make your first deposit of £10+, then place a £10 single bet from main balance at odds of EVS+ (2.00+) on any sports market (excluding Virtuals). As a result, the term has more historical than literal accuracy in today’s global betting market.
A sports betting odds comparison that only shows the current price for the home win, draw and away win tells you less than one that also shows the opening odds and the payout of each bookie. The hockey odds page lists the next games with the best price for each team, next to recent results and standings. The fact that bookmakers have large teams of maths experts working out odds means that beating them at their own game can be very difficult.
You can check the opening odds of each bookmaker, follow the odds movement over time and compare it with the current odds, so you know how the market has reacted before you decide when to bet. Odds change constantly between the moment a market opens and kick-off, and OddsPortal works as an odds tracker for every match. The same selection is priced differently by each bookmaker, so comparing bookmaker odds is the simplest way to make sure a winning bet pays out as much as possible.
They’re expressed as fractions, like 5/1 or 7/2, showing the ratio of profit to the original stake. Decimal odds make comparing bets straightforward because you’re seeing the total return value in one number. Higher numbers indicate higher potential payouts, while lower numbers signify favorites and lower returns relative to the stake. The key to understanding decimal odds is that they directly represent the total return. Decimal odds are the simplest format for many bettors, popular across Europe, Canada, and Australia. When novice bettors first realize that -125, 1.80 and 4/5 all represent the same probability, it can make them dizzy – but we’re here to lay it all out clearly.
The use of odds in gambling facilitates betting on events where the probabilities of different outcomes vary. However, in more variable situations, such as a multi-runner horse race or a football match between two unequally matched online bookies not on gamstop teams, betting “at odds” provides the possibility to take the respective likelihoods of the possible outcomes into account. Similarly, fair betting odds can be expressed as “(1−p)/p to 1”, “1/p for 1”, “+100(1−p)/p”, “−100p/(1−p)”, “D−N to N”, “D for N”, “+100(D−N)/N”, or “−100N/(D−N)”.
