Complete Guide to Arbitrage Betting

In this article I explain Arbitrage betting, also known as arbs and sure bets. I begin with the definition and then progress to how to calculate stakes. Let me warn, the bottom of this article is very important. If you are novice and read only the first sections and get started, chances are great you will lose a lot of money. In other words: if you are new to the topic, read this comprehensive article in full before making arb bets.

What is an Arbitrage Bet?

For sports, arbitrage betting can be defined as process of taking advantage of the differences in bookmaker prices by wagering every potential outcome of an event in such a way the return is the same regardless of which outcome is successful.

To show an example, let’s say an online betting site is offering a tennis player +105 (risk 1.05 to win 1.00) in a match. Another betting site is offering their opponent +105 too. If we stake $100 to win $105 on each we are guaranteed to make $5 no matter which player wins. This is because the winning bet pays $105 profit, and the losing one costs $100.

Arbitrage betting is only possible because there is a large number of bookmakers competing. You will only find arbs on select matches. I strongly suggest reading our site’s article Fade the Public. This explains the reason why and also has other information that is helpful for arbers to understand. It takes shopping many online betting sites to find arb opportunities. Thankfully this can now be done using odds feeds.

Odds Feeds for Finding Arbs

While we at Online Betting do offer odds comparison service on our homepage and league pages, it is only one small feature of this site. There are other website that specialize in only this. These sites display odds for more sportsbooks and markets. Likewise, as an arber, you will want to use each. Here are some recommended sites that can be used to easily shop odds.

  • – covers the largest number of sportsbooks and the most leagues. They are truly international and thus have an odds feed for sports leagues none of the other sites do.

    Take for example, Korean volleyball and Chinese basketball which Odds Portal covers. These leagues are not the main focus of any bookmaker. Likewise, the odds discrepancies between sites is often greater than it is for main markets. This means more arbs can be found. Odds Portal is also just as great for shopping major markets too on soccer, tennis, basketball, hockey, football and other sports.

  • – is of limited interest to players located in the United States as the bookies they support don’t accept US players. For everyone else this is a great feed to use. They don’t cover as many books as OddsPortal but they have far more markets.

    Here, you can find odds comparison on small props markets such as how many passing attempts an American football quarterback will have in a game, or the scorecast on a particular player and team in soccer. The list goes on and on. For some matches Odds Checker displays odds for over 200 different specials.

  • is very popular with American bettors as it uses a format they are most used to seeing with different point spreads listed on the same page. It is however extremely rare to find arbs between the books they cover. However, it is a great site to quickly see the odds at major betting outs. This is very helpful when shopping odds at other books by hand.

    My own personal example: none of the sites mentioned on this list display odds for US betting site I often find arbs between Sportsbook and SBR listed sites and therefore need to manually compare Sportsbooks odds to those on the opened SBR feed. Aside from all this, one areas you can find arbs with SBR is second half lines, meaning those released and open for betting only during the half. For these you need to be quick to bet.

The odds comparison sites just mentioned are all free to use. As a result there are small delays where sometimes it takes a few minutes for the odds to update. This can be frustrating to arbers as it means a lot of wasted time in loading two sites. A lot of serious arbers go with paid odds feeds such as Others develop their own system that scrapes the lines from books using their own programing and servers.

How to Calculate an Arb

There are many calculators on the web where you can just plug in the odds and it tells you how much to bet on each side. A couple of the more known examples are and You can find others by Googling a term such as arb calculator.

For those wishing to know the math, this is covered in my article on Hedging Sports Bets. Understand hedging is the same as arbing, the only difference is it is not done in advanced. A hedge is moving off a position at a later time, where an arb is betting all potential outcomes upfront.

How to Spot an Arb Bet

The article I just linked to on hedging shares the math but does not cover how to spot an arbitrage bet. When dealing with two way markets this is very easy. If the positive American odds are greater than the negative American odds you know an arb exists. You can then do the math to quickly calculate the stakes. However, when dealing with multi-way markets this is not as easy to spot. To show how it is done let me use a sincere example.

At the time I am writing this article I found the best odds available for each of the 3 wagering options on an English League One football match were:

– Coventy -161 (Coral)
– Draw +350 (William Hill)
– Crewe +632 (Pinnacle Sports)

In order to see if there is an arb available we need to get the implied probability for each wagering option. For this we can use our odds converter where I see -161 is 61.69%, +350 is +22.22%, and +632 is 13.66%. If I add those three probabilities together I see this totals 97.57%. This here is the trick! For reason the total is less than 100% I know for sure an arb is possible.

In this case I staked $500 on -161, $180.12 on +350 and $110.73 on +632. No matter which wins I get back $810.56. If you add all three bets together you’ll see in total I staked $790.86. This means I’m guaranteed $19.70 (2.49%) profit no matter which of the three bets wins.

Understand this example works with 4-way, 5-way, 6-way or however many way markets. If the implied probability on each outcome added together totals less than 100% an arb is available. However do note: a guarantee is not an actual guarantee. There are risks involved and things that can go wrong. I conclude this article by covering those.

Risks Arbers Face

Arb betting is often referred to as “risk free betting” or by the term “sure bets”. This is however only true in theory. The reality is there are many risks arbitrage players face. First and foremost the biggest risk is being stiffed. The majority of online betting sites are not regulated. While pure scam sites are one thing, there are other sites that pay over 99% of their clients but sometimes stiff the big winners.

What can happen is most sportsbooks have a catch all rule that allows them to effectively steal winnings without actually violating their terms and conditions. One example comes from Included in their long list of rules, buried in the fine print you will find: “WagerWeb is for recreational players only. (Syndicates, Professional Players and bonus abusers are not allowed)”.

This was just randomly chosen example. Most all sportsbooks have a similar catch all rule that mentions their site is for recreational players only. There only a couple sites actually friendly to professionals. Namely (US Players Allowed) and (No US Players). While these sites strictly follow “book a bet, pay a bet”, it is rare to find arbs with Bookmaker and when you find an arb with Pinnacle it is other site, not Pinnacle, that is offering the +EV side.

I discuss the above more in a minute, but first a point to understand. Arbers are the ones most likely to grow a large balance with a sportsbook. When it comes time to cash out, your account is then reviewed, they see all the bets you made at their site were likely steam chasing or arbs, and that you are not going to be a profitable client. If this is a less than reputable book that sometimes steals, you’re likely the one they will steal from. Some books will simply say you violated their rule as CLEARLY your action professional and NOT RECREATIONAL. They will then void all bets and refund your deposit.

The other more common thing to happen is arb protection in the form of voiding bets. This will happen at even super reputable books such as 5Dimes, TheGreek and others when it was in fact an error. If it is a gross error such as making a team -200 instead of +200 (transposing favorite and underdog) all sites will void the line and rightfully so. Obviously be careful not to arb these that are without a doubt an error. However, some otherwise reputable UK Bookies such as BWIN, ToteSport, Coral etc. have been known to do this when whether or not it was a bad line could easily be debated. The same is true with Asian Bookies like 188Bet and Dafabet. So, this is where you need to be careful. The biggest arbs (anything over a couple percent) often should be avoided.

As far as getting stiffed goes, there is a major learning curve. Those who are great at arbing are those who become great at learning the inter-working of various sportsbooks inside and out. They know which sites are slow paying, which pay fast, who is reputable, how a book should be rated, what they can get away with at each book and so much more. This is not something that can be learned overnight. It will only come with experience. Searching for and using online betting forums to communicate with other arbers or professional players about sportsbooks can help with this learning curve.

Other Risks to Note

There are other risks too, only some of which are covered below:

  • Arbs Do Not Last Long – Betting odds are constantly moving and it often takes only a single large bet for a site to realize they are offering a +EV line. A considerable risk is that you’ll confirm one bet and then have the other give a message saying sorry the line has moved. For that reason, be sure to make both bets at the same time and to confirm the one that is considered the off-market-price first.
  • Betting Limits Differ – Understand you can arb up to the maximum allowed bet. Between betting sites the limits are different. It is also not at all uncommon for books to give those they know are arbing personal limit collars. While everyone else can bet $5,000 on a game perhaps you can only bet $25.00. If you’re successful arbing you will for sure have limits cut to unusable levels at some of the online bookies you use. The first time you discover this you might be left with one bet already confirmed and the other giving you a message that your limits have been exceeded.
  • There is no Recourse for Hacked Accounts – This is very often the case. If someone logs into your account and chip dumps in that sites poker room, or just bets your balance away in the casino or sportsbook, most often you are out of luck. The biggest mistake arbers make is using the same password at each site, and using poor internet security practices.

    Likely, multiple $4.25 per hour Costa Rica based employees have access to your password at the sportsbook they work. They also have your name, address, phone number and email. Eventually one of them is going attempt to use that information to social engineer access to one of your other accounts. Be smart and keep your password unique at every site, and do not store that information online, or use porn tubes or torrent sites from the same internet device you use for betting. As a serious arber you are now a desirable target.

  • Deposit and Withdrawal Fees – Every now and then you will come across deposit and withdrawal fees that are not expected. For examples: BetOnline charges 6% on credit card deposits. charges $100 for most NETELLER withdrawal and $500 for wire transfer withdrawals. StanJames has a policy where if you deposit with Skrill you can’t use the sportbsook period. You can only user poker and casino and if you try to cash out without giving proper cover play they will add an admin fee of several percent.

    Arbers often join betting websites in a hurry to take advantage of arbs that won’t last long. It is important to be aware of these fees and policies at each site, as otherwise you might end up paying more in fees than you are going to make on the arb you joined the website to pursue.

  • Currency Exchange Fees – These can kill the value of an arb in a hurry. For low limit arbers lots of arbs can be found at (no US players) but this site operates only in Euro and UK Pound. If your e-wallet account used to deposit are set up as USD accounts, or some other currency, the currency exchange fees might exceed the value of the arb. Similarly, when betting with volatile currencies, such as betting with bitcoin, the frequent change in buy/sell prices adds additional risks.
  • Listed Pitchers – When betting baseball make sure to specify that the bet only has action when the listed pitchers start the match. Some sites give the option or default to action betting. With this, in the event of a pitching change the odds are changed to whatever the bookmaker deems a fair price is. Obviously this doesn’t work when arbing and can be very costly.
  • Make Sure Terms are Identical – Punters do sometimes mistake bet terms. For example one site is offering home/away (Moneyline betting) while the other is offering home/draw/away (1X2). In soccer most know to look out for this. In hockey some are surprised to learn certain books exclude overtime. There is section at where this is the case even when betting the Moneyline. Failure to realize this can be costly.
  • Rules Discrepancies – A tennis player retires early in a match. Is the bet void, does it have action at the current score. This is a big one. At Ladbrokes it is action after each has served. At 5dimes it is after 1 set is complete, at TheGreek after 2 sets are complete. At Bet365 it would have had to have gone the full match! Wow that’s four different rules! You need to know which rule the site you are using uses otherwise you could have a loss + a push costing you a heck of a lot of your bankroll on a failed arb. And, that’s just for one sport. How about how suspended games in baseball are handled, or ties in cricket, etc. There’s a lot one needs to pay attention to here.
  • Human Error Mistakes – I’ll conclude with one that is also common, that being simple mistakes. You bet the same side of the arb at both sites by mistake. Now you have maybe 20-40% of your bankroll at risk on a single play without realizing. If you win it is time to cash some out and celebrate. If you lose it sets you back months.

As you can hopefully now see arbitrage betting is far from being risk free or a sure bet. That said, there is money to be made in it, and some people become very good at it. The purpose of this article was to give you solid introduction while also properly warning about the risks.

Author: Jim Griffin