Sports betting
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, 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 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, spot-fixing, bad calls from officials at key moments, and overall match-fixing. Examples include the 1919 World Series, the alleged 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. 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 even though very few sports have.5 point scoring, to avoid the possibility of a tie.
- Total 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.
- Teasers. A teaser is a parlay that gives the bettor an advantage at a lower, but still positive, payout if successful.
- 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, 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. 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. 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 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.
- 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 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 bet applies only to the score of the first or second half. This bet can be placed on the spread 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. 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.
Bookmaking
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.
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
for different outcomes in single bet are presented either in European format, UK format, or American format. European format 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 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.| Decimal | Fractional | US | Hong Kong | Indo | Malay | Implied probability |
| 1.50 | 1/2 | −200 | 0.50 | −2.00 | 0.50 | 1 in 1.5 = 67% |
| 2.00 | Evens | +100 | 1.00 | 1.00 | 1.00 | 1 in 2 = 50% |
| 2.50 | 3/2 | +150 | 1.50 | 1.50 | −0.67 | 1 in 2.5 = 40% |
| 3.00 | 2/1 | +200 | 2.00 | 2.00 | −0.50 | 1 in 3 = 33% |
| x | To | Do this |
| Decimal | Fractional | x−1, then convert to fraction |
| Decimal | US | 100 if x>2; −100/ if x<2 |
| Fractional | Decimal | divide fraction, then x+1 |
| Fractional | US | divide fraction, then 100x if x≥1; −100/x if x<1 |
| US | Decimal | +1 if x>0; +1 if x<0 |
| US | Fractional | x/100 if x>0; −100/x if x<0; then convert to fraction |
| Decimal | Hong Kong | x−1 |
| Hong Kong | Indo | x if x≥1; −1/x if x<1 |
| Hong Kong | Malay | x if x≤1; −1/x if x>1 |
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.
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.