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

In tennis we follow the ATP and WTA tours every week, the Challenger and ITF events in between and the four Grand Slams, from the Australian Open to Wimbledon and the US Open. For beginners, our bet calculator shows the payout of a bet, for a single or an accumulator, in decimal, fractional or American odds. Enter how much you want to wager in total to see the stake for each outcome and the resulting profit. Our sure bets page shows a way to cover every outcome of a match across different bookmakers so that the combined odds return a profit, as long as the prices are still available when you place the bets.

Free bets valid 7 days from individual release, stake not returned, no cash out. To qualify for free bets, the new user must place and settle £20 on easyBet markets and use the bonus code EB20. With the rise of online sportsbooks and the legalization of sports betting across many states, odds are no longer exclusive to Vegas. “Vegas odds” traditionally referred to the betting lines set by Las Vegas sportsbooks, which were once the hub of sports betting in the U.S. When sharp bettors place heavy wagers, sportsbooks take this as a signal that these bettors have valuable information or insights. For example, if the majority of bettors back a popular team, the sportsbook may adjust the line to make the less popular team more attractive.

The odds are a ratio of probabilities; an non gamstop sports betting odds ratio is a ratio of odds, that is, a ratio of ratios of probabilities. In probability theory and statistics, odds and similar ratios may be more natural or more convenient than probabilities. 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.

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%. In formulating the odds to display the bookmaker will have included a profit margin which effectively means that the payout to a successful bettor is less than that represented by the true chance of the event occurring. In gambling, the odds on display do not represent the true chances (as imagined by the bookmaker) that the event will or will not occur, but are the amount that the bookmaker will pay out on a winning bet, together with the required stake.

Our basketball odds page brings together the games of the day, while results and standings go back several seasons. On the blocked odds page, you will be able to see matches or markets that online bookmakers are no longer offering odds for, which can signal a change in the market before other operators react to it. It is where the hot odds of the day show up first, and you can filter it by the last hour, 12 hours or 24 hours, by the percentage of bookies cutting their price and by market. The dropping odds page shows when the odds on a team, player or market have dropped before the start of a match.

For example, if a team is -5.5, they need to win by 6 or more points to win the bet. Instead of just picking a winner, you’re betting on whether a team can “cover the spread,” meaning they either win by a certain margin or avoid losing by too much. If you see +250, that team is the underdog; a $100 bet would return $250 if they win. Moneyline bets are the simplest form of sports betting, focusing solely on picking a winner. Some bets involve combining multiple outcomes for higher rewards, while others target specific in-game events or achievements. Once you’re familiar with the basic math, fractional odds become an easy way to see potential profits relative to the stake.

Free bet – one-time stake of £30, min odds 1.5, stake not returned. To qualify, place a min £10 bet from your cash balance at odds of EVS or higher—only your first bet counts, and it must not be voided or cashed out. Free bet – one-time stake of £10, min odds 1.5, stake not returned. Min 10 qualifying bets, stake not returned.

Moneyline odds use $100 as the evens line, with either positive or negative outcomes. If you’d like a bit more guidance, we have a full guide on how fractional odds work in betting. You may also see odds expressed with the lowest number first e.g. 1/2 or 2/7. Once you understand betting odds and the differences between them, reading them becomes easy.

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.