How betting odds work: what they are and how to use them
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. By shifting the line, they encourage bettors to wager on the opposite side, helping maintain even exposure on both outcomes. They range from player stats, like total points scored by a star player, to quirky events like the length of the national anthem.
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.
Excludes cashout, E/W, Multis, Ineligible Markets football betting not on gamstop & Odds Boosts. 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.
“Double the odds” applies to fractional odds profits only, with extra winnings paid in cash on settlement. Get your initial stake back (up to £30) credited in set football markets. Free bets valid 7 days from individual release, stake not returned, no cash out.
Min 10 qualifying bets, stake not returned. 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).
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. Moneyline, or American, odds are favoured by US bookmakers and punters, and are often expressed as positive and negative values (e.g. +250, -400). Bet £10+ on any sportsbook markets at odds of evens (2.00) or greater.
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.
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. 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 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)”. In gambling, odds are often given as the ratio of the possible net profit to the possible net loss, and sometimes this is called fractional odds.