sports betting

sports betting, form of gambling that involves wagering on sports.

Sports betting is one of the most popular forms of gambling because it taps into the passion of sports fans. A bet placed on a race or a game allows fans to prove their knowledge of a sport or to show their loyalty to a particular team or competitor. In addition to promoting camaraderie among friends, sports betting can enliven otherwise boring or one-sided contests when handicapping systems offering odds and point spreads increase the bettors’ stake in the competition.

Although legal sports betting is increasingly common, wagering on athletic competitions is often illegal and is conducted through bookmakers, also known as bookies (operating as individuals or for crime organizations), casinos, Internet gambling operations (which are legal in some countries), and other entities.

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Among the sports that have traditionally been associated with heavy betting are horse racing, dog racing, and boxing, but, increasingly, gamblers wager on the outcomes of most professional sports.

Types and methods

The oldest form of sports betting is probably one in which gamblers bet winner take all on the outcome of a contest. Today one of the most common forms of sports gambling is odds betting, in which a casino or bookmaker evaluates the contestants in a competition and assesses the probability of victory: 2 to 1, 5 to 1, 1 to 4, and so forth. With a $1 wager on a 2-to-1 underdog, for example, a bettor stands to pocket $2 if the underdog wins. A winning bet on the favorite offers a lesser payoff—e.g., a bet of $5 on a 2-to-5 favorite yields a $2 payoff.

For most races (e.g., horses, dogs, camels) and some games (e.g., jai alai), a pari-mutuel wagering system is used. In this system, introduced in the 1860s following the invention of the “totalizator” by Joseph Oller, a calculating machine records the amount bet on each competitor prior to the start of the contest. In horse racing, for example, the “totalizator” calculates the odds, based on the proportion of the total bet on each horse, and determines what should be paid to those who picked the winner. The bookmaker or track owner takes their share by skimming off a percentage of the total amount bet.

Betting on the games and matches of many sports use a system known as a point spread. Bookmakers determine the number of points that will serve as a spread for a particular contest. A bet on the favored team requires that the bettor yield (or give) the point spread. A bet on the underdog team grants the bettor the point spread. For example, an underdog team may be bet as +4, meaning it has four points added to its final score for purposes of determining the winning bettor. A −4 bet on a favored team wins only if that team wins by more than four points (or goals, runs, and so on).

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These systems can be mixed, and other factors can also be included, so that almost any dimension of a sport can be targeted for wagering. In ice hockey, for example, bettors might first get extra goals (or give them up) and then bet with odds. Across many sports, odds are often set for the exact score of the game. Among the many other propositions available is betting on both teams’ combined scores, known as an “over/under” bet because the bookmaker predicts the total points for a game and the bettor bets on the “over” (total points will exceed the predicted amount) or the “under” (total points will fall short of the predicted amount). At the beginning of a sports season, odds are given on whether a team will win a championship. Several bets also can be grouped together in what is known as a parlay bet. To win a parlay bet, the wagerer must win each of the individual bets that have been linked.

Pools and fantasy leagues are also popular methods of sports betting. They are largely organized by friends and coworkers, often using Internet-based companies to run their competitions; these companies also support large-scale versions. Pools range from predictions of the outcome of tournaments or the week’s roster of games to lotteries consisting of numbers that win if they match a final or partial score. Fantasy leagues involve bettors’ selecting actual athletes for a “fantasy team” before a competition (or season) begins. The person with the players who perform the best in terms of selected statistics wins.

Sports betting can be consistently profitable if gamblers have superior knowledge regarding athletes and teams, which many sports fans believe (usually falsely) they have. The proliferation of media coverage of sports and the variety of information services available give bettors a sense of control and confidence that encourages them to wager. They often keep betting even when they lose, blaming losses on bad luck or bad performances by players, coaches, or referees.

Legal status, ethical issues, and athlete involvement in betting schemes

Most bettors assume that athletes in competition perform to the best of their ability. Even the slightest indication that the athletes are “on the take” or “throwing” games or matches for pecuniary gain can irreparably harm a sport. As professional sports grew in popularity in the 19th century, so too did fears that gambling would corrupt the games. Indeed, unregulated gambling routinely attracted criminal elements looking to make easy money, and many scandals resulted. Most involved bribing athletes to lose matches purposely, or, in the case of football and basketball, to “shave” points—that is, to win by less than the point spread.

Among the most infamous of sports-betting scandals in the United States during the 20th century was the Black Sox Scandal, which occurred when eight members of the Chicago White Sox were charged with having thrown the 1919 World Series. In the 1950s, intercollegiate basketball in the United States was rocked by numerous bribery scandals. In subsequent decades it was the turn of German and Italian football (soccer) leagues to suffer from widespread corruption. Professional boxing has been associated with crime syndicates that have influenced prizefighters to “take dives.”

For a long period during the modern era of sports, horse and dog racing and a few other sports were the only sports that allowed gambling. Indeed, many sports organizations and governments enacted strict antigambling policies and laws in order to protect both the public and the legitimacy of sporting competition. The illegality of sports gambling, however, never diminished its popularity, and, by the second half of the 20th century, many countries were looking for ways to allow sports betting while avoiding the corruption that often seems to go hand in hand with it. Pro-gambling groups argued that legalization and regulation were the answers.

In the United States, differences between state and federal laws created a patchwork in which some forms of sports gambling were legal and others were not, though the Professional and Amateur Sports Protection Act, passed by Congress in 1992, imposed, in essence, a nationwide ban on sports betting (with a few exceptions). A ruling by the U.S. Supreme Court in 2018 ended that ban by enabling each U.S. state to establish and regulate sports betting by its residents. The result has been many billions of dollars in legal sports betting, which, in turn, generates tax revenue for states that allow licensed sportsbooks to operate. (Residents of states without legalized sports betting have used prediction markets to place sports bets, resulting in legal challenges from some of those states. Major League Baseball, Major League Soccer, and the National Hockey League entered partnerships with prediction market platforms in 2025–26.)

Great Britain legalized sports betting in 1960. In Germany and many other countries, the profits from lotteries and betting pools are used to subsidize amateur sports.

The influence of gambling on sports has been a source of controversy and, in some cases, legal action. A 1999 University of Michigan survey found that 45 percent of male college athletes in the United States bet on sports, and 5 percent indicated that they furnished information to gamblers. In 2002 it was revealed that members of the Jockey Club in Great Britain manipulated races by giving prohibited drugs to horses and by sharing inside information with gamblers. In 2004 it was alleged that soccer players in Italy skewed matches to help gamblers betting millions around the world.

By 2024 the major professional sports leagues in the United States and many of the leagues’ teams had commercial partnerships with sportsbooks, and broadcasts of their games were saturated with sportsbook advertising. Almost $37 billion was spent on legal sports betting in the United States during the first three months of 2024, according to a gambling industry group. During the first half of that year, several players and others connected to these leagues were suspended for betting on sports, with some facing legal charges. In Major League Baseball, for example, Shohei Ohtani’s interpreter, Ippei Mizuhara, was accused of stealing about $17 million from Ohtani to cover Mizuhara’s sports betting debts; Mizuhara pleaded guilty to fraud charges, while Ohtani was cleared of involvement with Mizuhara’s gambling. A player for the San Diego Padres was banned from the MLB for life because he bet on MLB and other baseball games, and the league also determined that one of its umpires had violated its policies on sports betting. In the National Basketball Association, a player for the Toronto Raptors was suspended from the league for life after an investigation found that he had been involved in betting on his in-game performance; legal action in the United States and Canada followed, and he pleaded guilty to a conspiracy charge in the U.S.

In October 2025 several active and former NBA players and coaches were indicted by the U.S. federal government for involvement in illegal sports betting schemes. The NBA responded by saying the overall integrity of the game was at risk and that the indictments proved existing safeguards were working. One former player pleaded guilty to two charges in April 2026.

Athletes in other sports were also accused of wrongdoing in the United States: in late 2025, federal prosecutors charged two Cleveland Guardians pitchers with throwing specific pitches in exchange for bribes from gamblers who bet on their pitches during MLB games; the players’ representatives denied the charges. Soon afterward, the MLB announced new limits on these types of prop bets made through major American sportsbooks. U.S. federal prosecutors moved again in January 2026, announcing charges against 26 people who, they alleged, were responsible for manipulating the outcomes of NCAA and Chinese professional basketball games so as to benefit bettors.