How betting odds work: what they are and how to use them

Last Updated on November 12, 2026

How betting odds work: what they are and how to use them

We are a team of software developers and experienced Matched Bettors, dedicated to helping you earn a sustainable, tax-free income every month. Plus, that gives you the opportunity to take advantage of the bookmakers’ bonuses and earn free cash. The issue with betting odds is that they’re always tipped in the bookmakers’ favour to allow them to make a profit. Because of the many factors involved, it is impossible to calculate exact probability in sports betting. In betting terms, probability is odds expressed as a percentage.

Futures keep you invested throughout the season, adding suspense as teams rise or fall and turning each game into a step toward your bigger prediction. For instance, if the line is 220.5 in an NBA game, you’d bet on whether the teams’ combined score will be over 220 or under 220.5. Totals bets, also known as Over/Under bets, focus on the combined score of both teams rather than who wins. Point spread bets are all about leveling the playing field between teams, making any game more exciting. We’ve followed social sportsbooks and sweepstakes casinos since they first started launching, and remain ahead of the game with rating the best prediction market apps.

The odds or amounts the bookmaker will pay are determined by the total amount that has been bet on all of the possible events. Sports information services are often used by professional and semi-professional sports bettors to help achieve this goal. It was about 3.7% less for wins by the visitors, and 5.7% less for draws. A study on soccer betting found that the probability for the home team to win was generally about 3.4% less than the value calculated from the odds (for example, 46.6% for even odds). The total of these three percentages is 100%, thus representing a fair ‘book’. In a 3-horse race, for example, the true probabilities of each of the horses winning based on their relative abilities may be 50%, 40% and 10%.

Bets in sports betting come in various forms, generally focused on picking winners, predicting score margins, or anticipating total points. Navigating betting odds can be difficult for newer players – especially when you consider that there are multiple odds formats used throughout the wagering world. Whether it’s choosing the top online casinos in the US or the best online casinos in Canada, we help you play with confidence across slots, tables, live dealer games, and more. Convenience is key, while reliability, functionality, live streaming, abundance of betting markets, and features are king. A “wholesale odds” index is an index of all the prices in a probabilistic market operating at 100% competitiveness and displayed without any profit margin factored for market participants. However, if the teams are evenly matched, both teams can have a negative line at the same time (e.g. −110 −110 or −105 −115), due to house take.

Odds can also be expressed as a number, by dividing the terms in the ratio—in this case it is unique (different fractions can represent the same rational number). For example, “odds of a weekend are 2 to 5”, while “chances of a weekend are 2 in 7”. Implied by this definition is the fact that the probability of an event is given by the ratio of favourable outcomes to the total number of possible outcomes. If k is any positive number then X to Y is the same as kX to kY, and similarly if “to” is replaced with “in” or “for”. Multiplying these probabilities by 100% gives the percentage. When probability is expressed as a number between 0 and 1, the relationships between probability p and odds are as follows.

Before a bet, check the archived results and historical odds of the teams or players involved, across leagues and tournaments worldwide. The value bets page compares the odds of each bookmaker with the average odds for the same outcome, highlighting the markets where one price stands out, with the probability included. OddsPortal has a number of betting tools that can bring your attention to interesting markets you may never have thought about betting on before, always with the best available price. The same price is 3/1 in fractional odds and +300 in American odds, which means a 100 bet wins 300 on top of the stake. This is a difficult task considering the huge teams of mathematicians that they employ.

Our real-time data updates live scores non gamstop uk betting sites as soon as a goal is scored, a point is won or a basket is made, and with live odds available for matches in-play, you can compare prices during a match and before it. 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.

When Moneyline odds are quoted as a positive number +X, it means that a wager pays X to 100. However in many situations, the possible loss (“stake” or “wager”) is paid up front and, if the gambler wins, the net win plus the stake is returned. From local leagues to international tournaments, our website shows the top price for every outcome before you bet. OddsPortal is a free odds comparison site where you can compare betting odds from leading bookmakers on every match. Odds comparison, also known as line shopping, means checking the price of the same outcome at several bookmakers and taking the highest one. With results, standings, predictions and the best odds on the same site, you can check the top price before every bet.

Minimum stake £ 30, minimum odds 1.5, stake not returned. Opt in, deposit & bet £10+ on any Sports market at odds of 2.00 or greater within 7 days of registration. Free bet valid 7 days from issue, usable on any Sport/Market as a 3+ fold ACCA with total odds 3.00–21.00, each leg 1.50+. Bonus funds are separate to cash funds and subject to 10x wagering requirement (bonus funds). #AD 18+ New players only. Opt in, deposit and bet £10 on any football market (odds 1/1+) within 7 days of sign up.