Sports betting

Overview

Sports betting is the activity of predicting sports results and placing a wager on the outcome. Sports bettors place their wagers either legally, through a sportsbook or bookmaker (colloquially known as "bookies"), or illegally through privately run enterprises. The term "book" is a reference to the books used by wage brokers to track wagers, payouts, and debts. Many legal sportsbooks are found online, operated over the Internet from jurisdictions separate from the clients they serve, usually to get around various gambling laws (such as the Unlawful Internet Gambling Enforcement Act of 2006 in the United States) in select markets, such as Las Vegas, or on gambling cruises through self-serve kiosks. There are different types of legalized sports betting now such as game betting, parlays, props, and future bets. They take bets "up-front", meaning the bettor must pay the sportsbook before placing the bet. Due to the nature of their business, illegal bookies can operate anywhere but only require money from losing bettors and do not require the wagered money up front, creating the possibility of debt to the bookie from the bettor. This creates a number of other criminal elements, thus furthering their illegality. There have been a number of sports betting scandals, affecting the integrity of sports events through various acts including point shaving (players affecting the score by missing shots), spot-fixing (a player action is fixed), bad calls from officials at key moments, and overall match-fixing (the overall result of the event is fixed). Examples include the 1919 World Series, the alleged (and later admitted) illegal gambling of former baseball player Pete Rose, and former NBA referee Tim Donaghy.

Types of sports bets in the United States

This is a list of sports bet types common to the United States.

Moneyline bets do not have a spread or handicap, and require the chosen team to win the game outright. The favored team pays lower odds than does the underdog; thus, it acts mainly as an enticement to take the underdog for a better payout. Sometimes a bettor may couple this type of bet on the favored team to increase the payout of a parlay. Spread betting are wagers that are made against the spread (ATS). The spread, or line, is a number assigned by the bookmakers which handicaps one team and favors another when two teams play each other and one is perceived as being more likely to win. The favorite "gives" points from the final score, and the underdog "takes" points. This number can also be in increments of half-a-point (.5) even though very few sports have .5 point scoring (i.e., The Ryder Cup), to avoid the possibility of a tie. For example, before game 5 of the 2012 NBA Finals, the Miami Heat were expected to beat the Oklahoma City Thunder. The line read: Miami −3.5, Oklahoma City +3.5. To determine who wins against the spread, the line is either added or subtracted from a team's final score. In the above example, if the bettor chose Miami, for him to win his bet, Miami would have to win the game by 4 points or more. If a bettor took Oklahoma City, they would have to win outright or lose by 3 points or fewer. If the final adjusted score is a tie, the bet is considered a push. The half point at the end is sometimes added to eliminate the possibility of a push. This is the most common type of bet in American sports betting. Total (Over/Under) bets are wagers made based on the total score between both teams. In an example, if an MLB game has a total of 10.5, an over bettor will want the combined total to be greater, and the opposite for a bettor taking the under. If the combined total is the same as the proposed total, the bet is a push. Most sports books refund all wagers on pushes, though a minority counts them as losses. Proposition bets are wagers made on a very specific outcome of a match not related to the final score, usually of a statistical nature. Examples include predicting the number of goals a star player scores in an association football match, betting whether a player will run for a certain number of yards in an American football game, or wagering that a baseball player on one team will accumulate more hits than another player on the opposing team. Parlays. A parlay involves multiple bets that rewards successful bettors with a greater payout only if all bets in the parlay win. A parlay is at least two bets, but can be as many as the bookmaker will allow. The possible payout of the parlay is determined by the combined likelihood of all bets placed. A parlay of riskier bets (more underdogs) will pay greater than a parlay of more likely bets (more favorites). In a parlay, all bets need to win in order for the parlay to win. If one of the bets on a parlay loses, the whole parlay loses. In the event of a push, the pushed bet would be taken out of the parlay and the parlay would bump down to a set of odds without that bet. Parlays are very appealing to bettors because they pay out much more than the total winnings of their constituent straight bets. However, it is much more difficult to hit on a parlay than it is on a single wager. In some states, parlays account for a substantial share of sportsbook revenue. In Louisiana, for example, parlays accounted for 70% of online sportsbook revenue during fiscal year 2024, according to the Louisiana Gaming Control Board. Teasers. A teaser is a parlay that gives the bettor an advantage at a lower, but still positive, payout if successful. The bettor selects the sport(s), number of games, and number of points given. If the bettor takes two NBA games at +6.5 it will adjust the individual bets at that rate. So a bet on a 3-point underdog at +3 will become a bet at +9.5 points, and for favorites, it will change a 3-point favorite at −3 to +3.5 points. Although the rules to win his bet are the same as a parlay, he is paid less than a regular parlay due to the increased odds of winning. If bets. An if bet consists of at least two straight bets joined by an if clause, which determines the wager process. If the player's first selection complies with the condition (clause), then the second selection will have action; if the second selection complies with the condition, then the third selection will have action and so on. Run line, puck line, or goal line bets. These are wagers offered as alternatives to money line wagers in baseball, hockey, or soccer, respectively. These bets are effectively point spread bets that have the same money line odds on either side of the wager (i.e., industry standard of −110 to −115). Sportsbooks will occasionally shift the moneyline by a few points on either side of these spread bets. Futures wagers. While all sports wagers are by definition on future events, bets listed as "futures" generally have a long-term horizon measured in weeks or months; for example, a bet that a certain NFL team will win the Super Bowl for the upcoming season. Such a bet can be made before the season starts in September for the best possible payout, but futures are typically available year-round, with payouts being reduced as the season progresses and it becomes easier to predict a champion. In this example, winning bets will not pay off until the conclusion of the Super Bowl in January or February (although many of the losing bets will be clear well before then and can be closed out by the book). Odds for such a bet generally are expressed in a ratio of units paid to unit wagered. The team wagered upon might be 50–1 (or +5000) to win the Super Bowl, which means that the bet will pay 50 times the amount wagered if the team does so. In general, most sportsbooks will prefer this type of wager due to the low win-probability, and also the longer period of time in which the house holds the player's money while the bet is pending. For this same reason, most professional bettors do not prefer to place futures bets. A sportsbook may choose to buy in-play futures wagers at a price below the actual payout before a championship is decided if the potential payout is very high (and thus, damaging to the sportsbook due to the money that may be lost). The most recent example of this was when Leicester City pursued and went on to win the 2015/16 Premier League. Head-to-Head. In these bets, bettor predicts competitors results against each other and not on the overall result of the event. One example are Formula One races, where you bet on two or three drivers and their placement among the others. Sometimes you can also bet a "tie", in which one or both drivers either have the same time, drop out, or get disqualified. Totalizators. In totalizators (sometimes called flexible-rate bets) the odds are changing in real-time according to the share of total exchange each of the possible outcomes have received taking into account the return rate of the bookmaker offering the bet. For example: If the bookmakers return percentage is 90%, 90% of the amount placed on the winning result will be given back to bettors and 10% goes to the bookmaker. Naturally the more money bet on a certain result, the smaller the odds on that outcome become. This is similar to parimutuel wagering in horse racing and dog racing. Half bets. A half (halftime) bet applies only to the score of the first or second half. This bet can be placed on the spread (line) or over/under. This can also be applied to a specific quarter in American football or basketball, a fewer number of innings in baseball, or a specific period in hockey. In-play betting. In-play betting, or live betting, is a fairly new feature offered by some online sports books that enables bettors to place new bets while a sporting event is in progress. In-play betting first appeared towards the

end of the 1990s when some bookmakers would take bets over the telephone whilst a sports event was in progress, and has now evolved into a popular online service in many countries. The introduction of in-play betting has allowed bookmakers to increase the number of markets available to bet on during sports events, and gamblers are able to place bets based on many types of in-game activity during the matches. For example, in football matches, it is possible to bet in on in-play markets including the match result, half-time score, number of goals scored in the first or second half of the game, the number of yellow cards during the match, and the name of the goal scorers. The availability of a particular sport and in-play markets varies from bookmaker to bookmaker. In-play sports betting has structural characteristics that have changed the mechanics of gambling for sports bettors, as they can now place a larger number of bets during a single sports game (as opposed to a single bet on who is going to win). One of the most important differences between being able to place an in-running sports bet opposed to a pre-match bet is that the nature of the market has been turned what was previously a discontinuous form of gambling into a continuous one. The gambling study literature has suggested that in-play sports betting may offer more of a risk to problem gamblers because it allows the option for high-speed continuous betting and requires rapid and impulsive decisions in the absence of time for reflection. There are three different types of in-play sports betting products(cash out, Edit my Acca, and Edit my Bet). Cash Out. Cash Out betting functionality lets the user of a betting website take profit early if their bet is coming in, or get some of their stake back if their bet is going against them—all before the event is over. Cash Out offers are optionally made by the website in real time on some current bets held by the user and are optionally taken by the user by clicking on a button on the webpage to "Cash out". Cash Out sports betting functionality developed on digital betting websites after 2008 with the evolution of betting exchanges. It was later adopted by online sports books and suppliers of betting software. 'Cash out' is offered to users by online sportsbook operators based on the profitability of offering the option to the user to divest their existing bet on an outcome and is sometimes available on singles and multiples. It is regularly offered on a wide range of sports, including American football, tennis, horse racing, basketball, and most other markets. You can Cash Out of bets pre-play, in-play, and between legs, before the outcome of the event. It has proved a key customer retention tool for sports book operators looking to capitalize on the use of mobile handsets while the bettor/user is also watching a given event. Edit My Acca. This feature allows gamblers to remove selections from their accumulator after the bet has been placed and in some instances after the selected event has started. The betting slip is then revised to feature the amended selections and a new potential return amount. This can be done online or via a mobile device. Edit My Bet. The "edit bet" feature can be used by gamblers to "unsettle straight accumulators" before matches have started or whilst they are in-play. The feature can also be used for to swap single bets for new bets, and the gambler is given a new bet selection valued at the bookie's cash out price to reflect live market/game odds for the original bet.

Bookmaking

The bookmaker functions as a market maker for sports wagers, most of which have a binary outcome: a team either wins or loses. The bookmaker accepts both wagers, and maintains a spread (the vigorish) which will ensure a profit regardless of the outcome of the wager. The Federal Wire Act of 1961 was an attempt by the US government to prevent illegal bookmaking. However, this Act does not apply to other types of online gambling. The Supreme Court has not ruled on the meaning of the Federal Wire Act as it pertains to online gambling. Bookmakers usually hold an 11–10 advantage over their customers—for small wagers it is closer to a 6–5 advantage—so the bookmaker will most likely survive over the long term. Successful bookmakers must be able to withstand a large short term loss. (Boyd, 1981) Many of the leading gambling bookmakers from the 1930s to the 1960s got their start during the prohibition era of the 1920s. They were often descendants of the influx of immigrants coming into the US at this time. Although the common stereotype is that these bookies were of Italian descent, many leading bookies were of eastern European ancestry.

Odds

Odds for different outcomes in single bet are presented either in European format (decimal odds), UK format (fractional odds), or American format (money line odds). European format (decimal odds) are used in continental Europe, Canada, and Australia. They are the ratio of the full payout to the stake, in a decimal format. Decimal odds of 2.00 are an even bet. UK format (fractional odds) are used by British bookmakers. They are the ratio of the amount won to the stake – the solidus "/" is pronounced "to"; for example, 7/1 is "seven to one". Fractional odds of 1/1 are an even bet. US format odds are the amount won on a 100 stake when positive, and the stake needed to win 100 when negative. US odds of 100 are an even bet.

In Asian betting markets, other frequently used formats for expressing odds include Hong Kong, Malaysian, and Indonesian-style odds formats. Odds are also quite often expressed in terms of implied probability, which corresponds to the probability with which the event in question would need to occur for the bet to be a break-even proposition (on the average). Many online tools also exist for automated conversion between these odds formats. In setting odds, the bookmaker is subject to a number of limitations:

The probability implied by the odds should be greater than the true probability for each possible outcome to guarantee positive expected profit. If the wagers on each outcome are made in ratio to the implied odds, then the bookmaker is guaranteed a profit (balanced book).

Legality and regulation

In many countries, bookmaking (the profession of accepting sports wagers) is regulated but not criminalized. The opinions of betting from sport authorities are mixed.

Argentina

In Argentina, the legality of sports betting is mainly regulated at the provincial level, given the federal nature of the country which grants each of its provinces the autonomy to legislate on gambling. This has resulted in a diverse landscape of sports betting regulation, with some provinces allowing and regulating sports betting extensively, while others maintain tighter restrictions. At the national level, there are efforts to create a more uniform regulatory framework, particularly for online sports betting, which has gained popularity and presents new regulatory challenges. The lack of cohesive federal legislation on online sports betting has led to a fragmented approach, although several provinces have begun to license online operators, seeking to regulate the market and provide consumer protections.

Brazil

In December 2023, Brazil enacted Law No. 14,790/2023, establishing a federal regulatory framework for fixed-odds sports betting and e-sports. The law authorizes both land-based and online betting, under the supervision of the Ministry of Finance and its Prizes and Betting Secretariat. Licensed operators must be based in Brazil, meet anti-money laundering and consumer protection requirements, and are restricted from using credit cards or cryptocurrencies. Only ".bet.br" domains are permitted. Operators are taxed on gross gaming revenue, and player winnings are subject to income tax. The regulated market launched in January 2025 with 14 companies granted full licences and over 50 operating under provisional status. Early market entrants included Betano, Bet365, Betsson, Sportingbet, Superbet, KTO, and Betfair.

Canada

Under the Criminal Code, provincial governments have the exclusive right to operate and license gambling in Canada. Legal sports betting is typically conducted through provincial lotteries via games promoted under brands such as Sport Select and Pro-Line. In 2021, the federal government passed legislation removing a long-standing prohibition of single-game betting from the Criminal Code. British Columbia, Manitoba, and Saskatchewan (via the Saskatchewan Indian Gaming Authority) offer online sportsbooks exclusively via PlayNow.com, Alberta offers them exclusively via Play Alberta, Quebec offers them exclusively via Espacejeux, and Atlantic Canada offers them exclusively via the Atlantic Lottery Corporation. These services enjoy a legal monopoly; private operators are not allowed to offer online gaming in these provinces. In April 2022, Ontario introduced a regulated internet gaming market open to third-party operators: in 2025, sports betting accounted for around $12 billion in wagers in Ontario's regulated market. In 2025, Alberta passed the iGaming Alberta Act, which will establish a similar model.

European Union

In the European Union (EU), sports betting legality varies among member states. Generally, the EU does not criminalize sports betting, but requires operators to obtain specific licenses within individual countries. Key directives, such as the Services Directive and consumer protection laws, influence the regulatory landscape. Each EU country sets its rules, impacting online and offline betting. Certain countries have recently updated regulations (such as the GlüStV 2021 in Germany), while the EU works to harmonize diverse laws.

India

The CEO of the International Cricket Council believe that sports betting, in particular in India, should be legalized to curb illegal bookies where match fixing has occurred from nontransparent bookmakers. According to the Law Commission of India, all forms of gambling are illegal. Online sports betting is a gray area and is not banned by any particular law in the Indian legal system. That is because specific provisions distinguish between games of chance and games of skill.

Spain

In Spain, sports betting is fully legal and regulated at the national level by the Dirección General de Ordenación del Juego (DGOJ), a body under the Ministry of Consumer Affairs. Since the passing of Law 13/2011 of 27 May on the regulation of gambling, the country has established a clear legal framework for the operation of sports betting both in physical establishments and on online platforms. This legislation covers licensing, advertising, and the protection of gamblers, ensuring a safe and responsible gambling environment. In addition, the regulations include measures to prevent pathological gambling and ensure that operators provide clear information on the odds and risks of gambling. In recent years, Spain has experienced a boom in sports betting, with a wide range of markets and events available to consumers. The DGOJ is responsible for monitoring and updating the relevant regulations to adapt to changes in the market and to protect the interests of players.

United States

In the United States, it was previously illegal under the Professional and Amateur Sports Protection Act of 1992 (PASPA) for states to authorize legal sports betting, hence making it effectively illegal. The states of Delaware, Montana, Nevada, and Oregon—which had pre-existing sports lotteries and sports betting frameworks, were grandfathered in and exempted from the effects of the Act. PASPA was struck down by the Supreme Court in Murphy v. National Collegiate Athletic Association in 2018, paving the way for other states to legalize sports betting. The United States National Football League was previously fully against any sort of legalization of sports betting prior to the late 2010s, strongly protesting it as to not bring corruption into the game. In May 2020, it was reported that since the Supreme Court's PASPA decision, over $20 billion had been spent on sports betting in the United States. As of January 2024, 37 states, Washington, D.C., and the territory of Puerto Rico have operational legalized sports betting, while North Carolina has legalized it though it sports betting operations will begin later in 2024. 30 states, Washington D.C. and Puerto Rico have also legalized online sports betting, though in 8 states that have legalized sports betting, betting can only occur through legal physical sportsbooks.