Betting arbitrage (“miraclebets”,”surebets”, sports arbitrage) is an instance of arbitrage arising on gambling markets due to either bookmakers’ differing views on event outcomes or errors. When conditions permit, by putting one bet per each outcome with different gambling firms, the bettor can make a profit regardless of the outcome. Mathematically arbitrage occurs whenever there are a group of odds, which represent all mutually exclusive results that cover all state space chances (i.e. all results ) of the event, whose suggested probabilities add up to less than 1.  From the bettors’ slang an arbitrage is frequently referred to as an arb; individuals using arbitrage are known as arbers. [citation ]
Arbitrage betting involves relatively large quantities of money, given that 98% of arbitrage opportunities yield less than 1.2 percent.  The clinic is usually detected quickly by bookmakers, who typically hold an unfavorable view of it, and this can lead to half an arbitrage bet being pinpointed. Arbitrage betting is almost always insufficiently rewarding due to detection, unreliable gambling websites, restricting of stakes, hackers, and scammers that use high percentage arbitrages to deceive bettors into supplying security credentials. 
Bookmakers generally disapprove of gambling arbitrage, and limit or shut the accounts of those who they suspect of participating in arbitrage betting.  Although arbitrage betting has been around since the beginnings of bookmaking, the development of the world wide web, odds-comparison sites and betting exchanges have produced the practice easier to carry out. On the other hand, these changes also made it easier for bookmakers to keep their odds in accord with the market, since arbitrage bettors are essentially acting as market makers.
In Britain, a practice has developed where exceptionally experienced”key men” use other people to place bets on their behalf, in order to prevent detection and increase access to retail bookmakers and allow the financiers or key arbitragers to stay in a computer to keep track of market movement.
Arbitrage is a very fast-paced procedure and its successful operation requires lots of time, experience, dedication and discipline, and especially liquidity.
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