A betting pool, sports lottery, sweep, or office pool if done at work, is a form of gambling, specifically a variant of parimutuel betting influenced by lotteries, where gamblers pay a fixed price into a pool (from which taxes and a house "take" or "vig" are removed), and then make a selection on an outcome, usually related to sport. In an informal game, the vig is usually quite small or non-existent. The pool is evenly divided between those that have made the correct selection. There are no odds involved; each winner's payoff depends simply on the number of gamblers and the number of winners. (True parimutuel betting, which was historically referred to as pool betting, involves both odds calculations and variable wager amounts.)
Betting pools are not connected merely to sports, as there are topics such as deaths and births which people can bet on. Death pools usually involve well-known individuals, such as celebrities and sports figures, which the participants predict will die within a certain period of time, with more points being assigned to individuals who are under the age of 80 years or appear to be in generally good health. On the other hand, birth pools involve individuals picking specific dates in which someone, who can be either a celebrity or friend, gives birth.
Contestants predict the outcome of sporting events that take place at a later time. The concept was introduced in 1923 by Littlewoods Pools where it was known as Uri[clarification needed] and based on football matches.
Today in England, sports lotteries are more commonly referred to as football pools. American sports lotteries often do not require contestants to purchase a lottery ticket or make an initial wager. Hockey pools are common in North America and footy tipping in Australia.
In the United States the most popular type of betting pool is the NCAA March Madness tournament. Leading up to the tournament contestants will fill out brackets that predict who will win. It is estimated that 58 million Americans participate in the contest every year. Mainstream media outlets such as ESPN, CBS, and Fox Sports host tournaments online where contestants can enter for free. Employers have also noticed a change in the behavior of employees during this time. They have seen an increase in the number of sick days used, extended lunch breaks, and even the rescheduling of conference calls to allow for more tournament watching. There are also many handicappers and pundits which offer advice for winning your bracket. Another popular type of betting pool is the college football bowl game. Millions of people bet on the winners of all 39 bowl games, as of the 2014-15 football season, every year.