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What Is Betting the Middle and Arbitrage Betting?

Written by: Richard Janvrin
8 min read

Any time you bet on sports, you’re comparing risk with reward. It’s the essence of gambling and the reason it’s so thrilling. But what if we told you there’s a finance strategy used by professional sports bettors that guarantees profits, one that involves taking both sides of a two-way bet simultaneously?

It’s called arbitrage betting, and people have been doing it since the dawn of bookmaking. Betting the middle is another really similar sports betting strategy that uses point spread bets instead of moneylines. We’ll explain betting the middle in detail too.

Called an “arb” for short, arbitrage betting isn’t as simple as going to a sportsbook and taking both sides of the same bet at once. If you did that, you’d be guaranteed one win and one loss, and because of the sportsbook’s commission you’ll always lose more money than you gain.

But by mixing various sportsbooks or finding lines that have moved, you can hedge your bets just like a professional sports bettor. Although this form of betting is typically practiced by pros, you don’t need to be one to pull it off; all that’s required is patience, research and discipline.

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In this article, we’ll tell you how arbitrage betting works with moneylines, and how betting the middle works with point spreads. We’ll also provide examples of each in action and show you exactly how to place these powerful and profitable bets.

How Arbitrage and Betting the Middle Works

Betting the middle involves taking both sides of a two-way bet. For instance, if you were betting on a football game between the Indianapolis Colts and Cincinnati Bengals, you’d bet on both teams to win, each at different sportsbooks that are offering different betting odds.

Both the spread and the moneyline work, but only the moneyline guarantees profit and is truly considered arbitrage betting.

When you practice arbitrage betting on the moneyline, you’re guaranteed to make a profit because you’re selecting odds that produce more profit on your winning bet than the amount lost on your losing bet. This involves finding the best odds in the market and then calculating exactly how much should be staked for each wager in order to ensure you’re making a profit.

The profit margin won’t be big; it’s typically under 5%, so sports bettors must lay a lot of money in order to get a decent return.

Arbitrage Betting Summary:

  • Placing an arb involves taking both sides of a bet.
  • To take both sides of a bet, you must track down the best odds for each team at separate sportsbooks. This can be done easily with odds comparison sites such as Odds Checker.
  • If you suspect an opportunity for arbitrage, you must calculate the total implied probability to ensure profits. We’ll explain how to do this in the next section.
  • If the total implied probability confirms an arbitrage opportunity, you then determine how much to stake on each wager using an arbitrage calculator.

Betting the middle with spreads also involves taking both sides of a bet, but instead of being guaranteed profit, you get the the chance to win both your bets. To do this, you’ll need to find two game lines with different point spreads. The “middle” is the gap between both spreads. To win both bets, the win margin must end up in the middle of both teams’ spreads. If you do win twice, you gain more profit than you would from hedged moneyline bets.

A second winning scenario exists with middling betting that involves winning one bet and pushing the other. This comes from the total win margin falling on either side of the middle. We’ll explain further with a detailed example in the next section.

Betting the Middle Summary:

  • To bet the middle, find two different gamelines with unique point spreads for the same game. Ex. -3 and -5.
  • Take both sides of the bet to capitalize on the gap in the point spread. Ex. Take the favorite at -3 and the underdog at +5.
  • You win twice if the favorite beats the underdog by the number of points isolated between both spreads. 4 points is the magic number in this example. If the favorite wins by 4 points, both bets cover the spread.
  • You win one bet and push the other if the favorite beats the underdog by the number of points surrounding the middle. Ex. If the favorite beats the underdog by 5 points, the favorite covers and the underdog bet pushes.

Arbitrage betting may sound complicated at first, but it’s a crucial component of sports betting strategy.

Some bettors consider it one of many tools needed to gain an edge on sportsbooks, while others bet exclusively through arbitrage. However you use it, it will give you an edge in the long-term. We’ll go through an example of each type of bet to simplify the concept.

Examples of Betting the Middle

Betting the middle typically refers to finding middling opportunities with the point spread in football and basketball, while arbitrage typically refers to hedging two-way bets through moneyline wagers.

While they’re both similar and work on the same basic concept, there are a few important details to understand for each. We’ll start with the simplest form of betting the middle: using point spreads.

Betting the Middle with Point Spreads

When you bet the middle using point spreads, you’re taking advantage of a gap between two lines for the same game. This gap could be the result of differing opinions of the oddsmakers at different sportsbooks, or it could be from a line change at a single sportsbook. For example, one source may have a 7-point spread for a game, while another source may have a 10-point spread for that same game. In this case, the “middle” is the 8-9-point gap between both spreads.

So how do you take advantage of that gap? By betting strategically, you could end up with one win and one push, or even better, two wins. We’ll show you how this is possible with a historic example of a line change for a Super Bowl game between the Pittsburgh Steelers and the Dallas Cowboys in 1979.

Outcome No. 1 for Betting the Middle: Two Wins

Pittsburgh Steelers -3.5

Dallas Cowboys +3.5

When the lines first hit the market, the Cowboys were 3.5-point underdogs to the Steelers. After a lot of action was put on Pittsburgh, the line changed to encourage more action on Dallas.

Pittsburgh Steelers -4.5

Dallas Cowboys +4.5

With this line change, any bettors who took the Steelers at -3.5 now had an opportunity to bet the middle by taking the Cowboys at +4.5. Betting the middle is only possible when you take the favorite at the sportsbook with the tighter spread, and the underdog at the sportsbook with the wider spread. There also needs to be at least 1 point difference between both spreads to pull it off.

In 1979, the bettors who took Pittsburgh at -3.5 and the Cowboys at +4.5 had a “middle” gap of 4 points. By taking both bets, they would win twice if Pittsburgh beat Dallas by exactly 4 points, a win margin that’s fairly uncommon in the NFL.

To the good fortune of many bettors and the dismay of many sportsbooks, the Steelers ended up winning that game 35-31. It was the worst result imaginable for sportsbooks, who refer to that day as Black Sunday for all the money they lost.

Outcome No. 2 for Point Spreads: One Win, One Push

In our 1979 example, there was a 1-number gap wedged between two spreads that contained a half-number, meaning there was no opportunity to see the other potential outcome of betting the middle: winning one bet and pushing the other.

Had the spread been whole numbers instead, the two-way bet would have been even more secure with the potential to push. Let’s go through an example to illustrate what we mean.

Line #1

  • Pittsburgh Steelers -3
  • Dallas Cowboys +3

Line #2

  • Pittsburgh Steelers -5
  • Dallas Cowboys +5

In this theoretical example the gap between both spreads is 4 points, just like our prior example. However, in this case, the spreads are whole numbers, meaning teams could also push if the win margin is exactly 3 or 5 points. That possibility for a push is an extra layer of security for your bet.

For instance, if the Cowboys beat Dallas 10-7, you’d win your Dallas (+5) bet, but would push for your Pittsburgh (-3) bet. Here are the four outcomes possible in this example:

  1. The Steelers beat the Cowboys by 4 points, and you win both your bets.
  2. The Steelers beat the Cowboys by 3 or 5 points, and you win one bet and push the other.
  3. The Steelers beat the Cowboys by more than 5 points, and you win one bet and lose the other.
  4. The Steelers beat the Cowboys by fewer than 3 points, or the Cowboys upset the Steelers. In both cases, you win one bet and lose the other.

As you can see, there’s a nice 3-point range where you can make a good profit with a lower level of risk than standard bets. Betting the middle is most popular with college sports because their big point spreads undergo more line movements than those of professional leagues.

That doesn’t mean betting the middle is impossible with NFL and NBA, there are just fewer opportunities. Make sure to keep your eyes on the lines and act fast when you spot one.

Arbitrage Betting with Moneylines

When we talk about a “risk-free bet,” we’re talking about arbitrage betting with moneylines. This strategic form of betting has you choose both sides of a two-way bet with odds that guarantee a profit. By comparing how much you’d win on one bet with how much you’d lose on the other, you can spot opportunities to come out ahead by taking both bets.

The first step of arbitrage betting is to shop the odds market for a single game. You need two sets of odds from two different sportsbooks in order to hedge your bet, and they need to be the best odds on the market for both the underdog and the favorite.

You can do this manually by keeping track of odds at your favorite sportsbooks, or you can do it with an odds comparison site, such as Odds Checker. With time, you’ll get better at recognizing value odds, so be patient when getting started.

In order to spot an opportunity for an arb using American odds, the favored team’s negative odds must be lower than the underdog’s positive odds. -115 is lower than +125, for example, and -110 is lower than +115.

Here’s what an arbitrage opportunity looks like:

  • Dallas Cowboys -115
  • Arizona Cardinals +180

As you can see, Arizona’s +180 odds are higher than Dallas’s -115 odds, meaning there’s potential for an arbitrage. To confirm, we must determine the implied probability of each bet and combine them; if the sum is less than 100%, taking both bets guarantees profit regardless of the outcome. In real life the profit margin is typically less than 5%.

To determine the implied probability of each team, you can use online arbitrage calculators, or do the calculations by hand. We’ll start with converting Arizona’s +180 odds to their implied probability of winning the game.

Formula for Positive Odds:

The formula for calculating implied probability from positive odds is 100/(Positive Odds+100). Here’s what that looks like with the numbers from our example:

  • 100/(180+100)=0.357

Then you can multiply the answer by 100 to make it a percentage.

  • 357*100=35.7%

In this example, we added Arizona’s +180 odds to 100 and divided the sum by 100, giving us 35.7%, which is the oddsmakers’ assessment of Arizona’s probability of beating Dallas. This formula can be used with underdogs only. To determine the Cowboys’ implied probability, we need to use a different formula designed to flip negative odds into positive digits.

Formula for Negative Odds:

The formula for calculating implied probability from negative odds is: (-[Negative Odds])/(-[Negative Odds]+100). Let’s plug in the numbers from our example:

  1. (-[-115])/(-[-115]+100)
  2. The double-negatives change the formula to 115/115+100=0.534
  3. 534*100=53.4%

In this equation, we added 115 to 100 and divided the sum by 115, giving us an implied probability of 53.4%. Now that we have the implied probability of both teams, we can add them together to confirm that the total percentage is under 100%.


The sum of the implied probability of both teams is under 100%, meaning there’s definitely an opportunity for arbitrage betting. The next step is determining exactly how much to stake on each bet, which requires an arbitrage calculator or converting the odds to decimal by hand. We’re going to use a standard calculator found online for free to show you how it looks.

Bet Dallas Cowboys Arizona Cardinals Total
Odds -115 +180
Implied Probability 53.4% 35.7% 89.1%
Total Staked $100 $66.79 $166.79
Payout $187 $187 $187
Profit $20.21

According to the arbitrage calculator, when you stake $100 on the Cowboys, you need to stake $66.79 on the Cardinals in order to guarantee a profit of $20.21 regardless of which team wins. These amounts can be scaled up and down, but the ratio needs to stay consistent.

For example, if you increased the stakes to $1,000 on the Cowboys and $667.86 on the Cardinals, you’d get a profit of $202.14.

Betting the Middle with Totals

You can expand your betting landscape by betting the middle with totals in addition to spreads. Just like a spread bet, the total has two sides: the over and under. The line on a total bet can sometimes shift up or down, providing middling opportunities for savvy bettors. If you find two different totals at different sportsbooks, or the line moves enough, you have an opportunity to win both the over and the under simultaneously.

In order to bet the middle on totals gamelines, you have to take the under for the higher total and the over for the lower number. That creates a gap where both bets can win. We’ll illustrate with an example.

NBA Total Gameline 1:

  • Milwaukee Bucks O 217.5 (-110)
  • Los Angeles Clippers U 217.5 (-110)

NBA Total Gameline 2:

  • Milwaukee Bucks O 220.5 (-110)
  • Los Angeles Clippers U 220.5 (-110)

In this example, the total is 217.5 points on Gameline No. 1 and 220.5 on Gameline No. 2; the middle includes 218, 219 and 220. As mentioned, we want the over to be lower than the under, so we’ll take the over at 217.5 and the under at 220.5. Now, if the total points scored between the Bucks and Clippers is 218, 219, or 220, we win the over bet and the under bet.

Betting the over/under can also take place in the props market for things like total wins in the regular season. While these two-way wagers do provide an opportunity to bet the middle, they have lower betting limits than traditional gamelines, making them less appealing to professional sports bettors.

If you’re working with a small bankroll, the props market can be a great learning ground for betting the middle.

Sportsbooks’ Tolerance of Arbitrage Betting

As you begin line shopping across various sportsbooks, you’ll get a feel for how each company operates. For instance, not all sportsbooks allow arbitrage betting. Bookies have no choice but to move lines when a lot of money is placed on one side, and much to their displeasure, that leaves opportunities for arb bettors looking to capitalize on excellent odds.

If a sportsbook is against the practice and suspects that you’re hedging bets, your account can be banned or suspended.

That being said, some sportsbooks welcome arbitrage betting and pride themselves in not restricting people’s betting behavior. However, these books are usually the hardest ones to make money off of because they typically have the sharpest lines in the market. As you hone your arbitrage betting strategy, you’ll learn to balance sportsbook security with line value.

One way to increase security is to stick with reputable sportsbooks. Length of time in the business can help you assess a sportsbook’s credibility, as it’s hard to tell how long a new book will stay in business. On top of that, you can familiarize yourself with betting behavior that raises flags with anti-arb books.

For example, placing the max bet allowed on a stale line is one way to get noticed and potentially banned. Find out what works best for you with the sportsbooks you trust to ensure a positive arbitration betting experience.

Arbitrage Betting: Eliminating Risk Through Hedged Bets

If you want to make a profit betting on sports, you need to move beyond the most common bets. Sure, you could maximize a payout by parlaying bets, but when you’re working with a single sportsbook, the reward will always reflect the level of risk involved.

With arbitrage, you can either eliminate the risk on the moneyline, or reduce it when betting the spread. In order to pull it off, you’ll need to keep your finger on the pulse of game lines.

For that reason, arbitrage betting isn’t recommended for beginner sports bettors, but as you progress in your sports betting journey, you’ll get to a point where you can:

  • Predict when a line will move a certain way.
  • Spot value (or arbitrage opportunities) right away.
  • Know which sportsbooks are credible and which aren’t.

Once you develop these skills, transitioning to arbitrage betting is a lot easier. You’ll be able to snap up lines with the confidence of a seasoned bettor. Arbitrage betting is the final step to developing a sound sports betting strategy, master it and you’ll be rolling with the pros.

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Richard Janvrin

575 Articles

After graduating from the University of New Hampshire with a BA in Journalism, Richard Janvrin has been covering iGaming and sports betting since December 2018. Richard has covered betting at Bleacher Report, Gambling.com, The Game Day, Forbes, and more.

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