Arbitrage betting is a technique that allows you to bet on all possible outcomes in a sports betting market with different bookmakers to make an almost guaranteed profit. In this guide, we explain how it works, how to find arbitrage opportunities and how to take advantage of them.
Arbitrage betting works by capitalising on the price discrepancies that can be found between different bookmakers. These discrepancies sometimes make it possible to make bets on all possible outcomes in an event and generate a profit no matter what happens.
Allow us to illustrate the principle with a purely theoretical example. The toss of a coin has two possible outcomes. There’s a 50% chance that the coin will show Heads and a 50% chance that the coin will show Tails. If a bookmaker were to offer true odds for both of those outcomes, he’d offer odds of 2.00 for Heads and 2.00 for Tails. In that scenario, we could bet £1 on both outcomes, and our return of £2 would be exactly the same as our total outlay.
But imagine if two bookmakers disagreed that the odds of Heads or Tails showing were 50/50. Maybe one bookmaker would offer odds of 1.90 for Heads and 2.05 for Tails. And the other bookmaker would do the opposite, offering 2.05 for Heads and 1.90 for Tails.
In this scenario, we could bet £1 on Tails at 2.05 with the first bookmaker and £1 on Heads at 2.05 with the second bookmaker. Then, whatever happens, we would get back £2.05, yielding us an overall profit of £0.05.
Yes, it’s a very small profit, but arbing gives you virtually guaranteed bet wins, so that’s to be expected. And while you’re never likely to find two bookmakers disagreeing over the toss of a coin, there will always be online betting sites that have slightly different opinions about who will win a particularly close sporting event, such as a tennis match.
In order to practice arbitrage sports betting, you need to find an event about which different bookmakers have different opinions. This isn’t always easy. In fact, the hardest part of arbitrage betting is finding suitable opportunities. Here are some tips on how to go about this task:
If you haven’t done so already, take a good look at our Betting Odds Explained guide, which will give you a good introduction to something called implied probability. When you’ve done that, get used to calculating the implied probability for the odds that bookmakers publish. Then bear in mind this golden rule of arbitrage betting: For an event to qualify as a sports arbitrage opportunity, the total implied probabilities for all outcomes must be lower than 100%.
For example, if you can bet on one player in a tennis match with one betting site and the other player with another betting site, and their combined implied odds are less than 100%, you can make a profit overall. The lower the implied odds total, the more profit there is to be made from your arb bets in the match.
Shopping around for the best possible odds is essential for arbitrage betting. For that reason, it makes sense to sign up with multiple sportsbooks that cater for your preferred sports. For example, if you’re a big football fan, you could sign up with a handful or even all of the best football betting sites. That will enable you to strike a bet quickly with any of them if the odds they offer. It will also give you the chance to take advantage of the free bet offers that betting sites give to new customers.
You’re very unlikely to find sports betting arbitrage opportunities in the main markets for big headline events that the world and his wife are talking about. You should look instead at small markets that tend to fly under the radar. For example, look at the Over/Under markets for low-profile games in basketball and other high-scoring sports, as well as the odds being offered about similarly low-profile snooker, tennis, and American Football matches.
According to the conclusion of this Queen Mary University of London study on arbitrage betting in football, “divergence in odds between bookmakers is much higher for lower divisions.” So even academics agree with this approach.
When you’ve found an event that is suitable for arbitrage betting, you’ll need to work out how much to stake on each of the outcomes. You could use an arbitrage betting calculator to do this, but we still think it’s important that you know how to calculate your stakes manually. Here, then, is how to do just that:
First, if you haven’t already done so, work out the implied probabilities for each outcome in the event and add them together to give an Odds Total percentage. Then decide how much you want to wager on the event as a whole. We’ll call that your Wager Total.
For example purposes, we’ll say that you’re going to bet on a tennis match. You can bet on Player A at odds of 2.00 with one bookie and on Player B at odds of 2.10 with another bookie. The implied probabilities for those odds are 50% and 47.62%, so the Odds Total percentage would be 97.62%.
In this scenario, if you were to bet an equal amount on each player, a victory for Player A would only cover your total outlay. For that reason, it’s necessary to divide your Wager Total according to the odds available so that you make a known profit whichever player wins.
To calculate your stake for outcome A, the formula is as follows:
(Wager Total x Outcome A Implied Odds%) divided by Odds Total%
So if you wanted to bet £100 on the match as a whole, your calculation for Player A would be:
(100 x 50.00%) divided by 97.62%
= 50 divided by 97.62%
= £51.22
The formula required to calculate your stake for Player B is:
(Wager Total x Outcome B Implied Odds%) divided by Odds Total%
You would therefore calculate:
(100 x 47.62%) divided by 97.62%
= 47.62 divided by 97.62%
= £48.78
You now know that you need to stake £51.22 on Player A at odds of 2.00 and £48.78 on Player B at odds of 2.10. That’s a total outlay of £100. Whichever player wins, you’ll get back £102.44, which is a £2.44 profit.
As we said earlier, using an arbitrage bet calculator makes life easy by doing all of the arithmetic for you. But at least you now know how to work things out manually should the need arise.
Now that you’ve seen how to find arbitrage bets and how an arbitrage bet works, we should pause to consider the advantages of this approach. There are several, as detailed below:
A big advantage of sports arbitrage is that it eliminates the need to make predictions of any kind. Because you are betting on all possible outcomes of an event, it simply isn’t necessary to even consider who will win and who will lose. Whatever the outcome, one of your bets will win and provide a large enough return to cover your entire outlay and leave a little profit left over.
Arbitrage betting has been around for decades, but it has only become a viable opportunity for regular sports bettors thanks to the continuing popularity of making bets online. The more online betting sites you have access to, the more arbitrage opportunities you are likely to find. While offline bettors might have once considered themselves lucky to find one or two sports arbitrage opportunities per month, online bettors can usually expect to find a handful every week.
Perhaps the biggest advantage of arbitrage betting is that it presents you with the chance to make bets which are almost guaranteed to win. We say almost guaranteed because there are some situations that can cause arbitrage bets to fail, and we’ll talk more about that in a moment. But for now, arbitrage betting is an approach that’s as close to risk-free as you’re likely to get.
As we’ve just hinted, arbitrage betting isn’t without its potential drawbacks, and you should run a mile from anyone who says otherwise. Here are the main ones that you need to be aware of:
While it’s quite rare, a bookmaker has the right to cancel bets that you or any other bettor has already made. This is most likely to happen if a bookie has accidentally made the wrong odds available about an outcome and wants to rectify the situation. Whatever the reason, if you have one part of your arbitrage bet cancelled, there’s a big risk that you won’t make a profit unless you can quickly place the cancelled bet elsewhere at the same odds.
Another drawback of making a bet arbitrage style is that the potential profits will always be small. You can forget about doubling or tripling your money on a single event. In most cases, you’ll do very well to make a profit of even 5% on your outlay. You’ll occasionally make a slightly larger profit – perhaps 10% or maybe even 15% – but those kinds of opportunities are few and far between.
Many arbitrage betting fans like to bet with large stakes to make such small percentage returns worthwhile, but that really ramps up the element of risk if something goes wrong.
With potential profits being so small in relation to the outlay required, it’s absolutely essential that you are accurate in your calculations. This is why many people use an arbitrage calculator. UK odds in fractional form might need to be converted into decimals for certain calculators (our free Bet Calculator can help here), and that’s another area in which accuracy is just as important. Make a simple arithmetical mistake, and it could cost you dearly.
Even if you sign up with a dozen different betting sites, finding arb betting opportunities will take time and effort. It could take you an hour or two to find a market that gives you the chance to make £5 from an outlay of £100, and that doesn’t equate to a particularly good hourly rate. There are websites that will claim to find and highlight opportunities for you in return for a subscription fee, but you’ll still need to bet enough to cover such a fee, let alone make a profit.
The final drawback we want to mention is that bookmakers can ban anyone for a number of reasons. Because of the increasing number of people who are trying to make arbitrage bets today, it’s something that’s becoming much easier for betting sites to spot. And if a bookmaker sees that you are employing an arbitrage strategy, it won’t hesitate to put a strict limit on how much you can bet or to ban you entirely from betting at that site altogether. This is known as being gubbed.
The potential drawbacks of betting arbitrage style make it a tough one to recommend as a primary strategy. That said, it can certainly be useful when used as an adjunct to traditional sports betting. Here are some tips on how to keep a low profile while you’re doing it:
While arbitrage betting can certainly be a useful approach to generating profits from sports betting, it isn’t foolproof by any means. Although it’s a technique that yields modest profits far more often than not, it’s also one that can be quite costly in terms of the time and effort required to use it effectively. That said, you now have a good understanding of how it works and how to implement it in a careful and conscientious manner should you choose to do so.
Arbitrage betting is a technique in which you bet on all possible outcomes in an event at odds that will yield a profit no matter which one occurs.
Arbitrage betting is perfectly legal, but betting sites frown on it for obvious reasons. If a bookmaker suspects that you are using this technique, your account may be restricted, or you could be banned from betting on the site altogether.
Arbitrage betting works just as well in the UK as it does in any other country which allows you to wager on sports online. When arbitrage betting, UK fractional odds may need to be converted into their decimal equivalents to make it easier to calculate stakes.
When done correctly, and assuming that the bookmakers involved don’t cancel any of your bets, sport arbitrage is profitable. However, the profits yielded by this technique tend to be very modest, with even a 5% profit on outlay being considered quite good.
Ian Bruce joined Safest Betting Sites in 2024 as Senior Sports Editor to oversee the quality and usefulness of its gambling content. He originally developed an interest in betting after landing a winning Yankee on his first attempt. He then spent years figuring out how to replicate that success. Along the way, he became one of the UK’s leading writers on the topic of betting and gaming. Ian’s career has now spanned more than three decades, and his enthusiasm for systematic and responsible betting hasn’t waned one bit. However, his preferred approach to winning these days is Dutching, for the simple reason that “It’s a lot easier than landing Yankees.”
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