Advantage Betting Using Implied Margin

Using the implied margin to find good bets is one of the many ways in which a sharp bettor can find an advantage over a sportbook. Below, we will lay out a few terms and explain what Implied Margin is. Most importantly, we will then discuss how it can be used to the bettor’s advantage.

Understanding the Sportbook’s Advantage

To be able to understand what Implied Margin is, we first have to get a handle on the basics component of the bookie’s strategy. The main advantage that a sportsbook has over a bettor is called sportsbook margin (it can also be know as the “hold” or the “vig”).

Sportbook holdWhat this percentage means is that if a sportbook takes even bets on each side, then it will make that percent of money bet.

The example to the left illustrates a game between the NY Jets and the Baltimore Ravens. The home team Ravens are a 15.5 point favorite at the Orleans Casino. The odds on each spread bet is -110. This means that the bettor must bet $110 to win $100 or some variation of money at that ratio. This is subsequently why it’s hard to beat the book. Sparing everyone the math, the hold here for this bet is 4.76%. This is pretty standard for most casinos across the world.

Understanding the Bettor’s Advantage

Now, what can a bettor do to get an edge on a sportsbook? There are two things that we will briefly cover here as they relate to implied margin.

Line Shopping

Aside from having a sports almanac (like in Back to the Future 2!), line shopping is the biggest advantage one has over a sportsbook.

Spread Best Line

In the above example, let’s say you love the Baltimore Ravens to crush the spread. At some places, the line is at -15.5 and at others it is at -15. However, we can see that at MGM, the line is at -14.5! It isn’t much, but these are the small wins that a bettor needs to claw back it’s chances against the books.

Break Even Percentage

The break even percentage is probability in which you would need to win to break even against the sportsbook. If both sides of a bet have -110 odds, then the break even percentage of the bet is 52.38%. This is a pretty common term that’s thrown out there is the community stating that to be a profitable bettor you must win 52.38% of the time. This isn’t true, but we’ll get to that in a minute.

What is Implied Margin?

Now that we have an understanding of the sportsbook hold, line shopping and break even percentage, we can attack Implied Margin!


The example above shows the money lines at different sportsbooks in Nevada. Note that at each individual sportsbook, the hold is in the 4.7% range. However, we have an advantage in that we can choose to bet at any of these spots! To calculate implied margin, we use the best line available at the listed books. In the example above, it turns out that the bettor ends up with a 1.2% advantage! These advantages rarely last very long because the sportbooks are generally pretty quick to match their lines with their competitors.


All of our match up pages have implied margins listed for money lines, spreads and over/unders. A cool benefit of our site is that we automatically calculate the implied margin where difficulties exist. One must know the value of each point in every sport for this type of betting to work correctly. We do this automatically to give the bettor a slight edge against the books!