What is EV Betting?

Expected Value (EV) betting is an essential sports betting strategy that attempts to measure the difference between the perceived value of a bet and the odds offered by a sportsbook.

Any experienced sports bettors should take the time to research EV betting because not only does it offer some incredible potential profit-making opportunities, but it also gives you a better understanding of the math behind the entire gambling industry.

On this page, we’ll be breaking down key concepts behind positive EV betting, exploring a number of strategies, and discussing the general concept of sports betting value at large to help you become a more informed and knowledgeable bettor.

What’s the Vig?

To understand EV gambling you need to understand one thing, sportsbooks are trying to make a profit on every single bet they offer, and the lines are set accordingly. The vig is basically the amount of profit a sportsbook expects to make on a particular bet.

Let’s look at a simple spread betting example. Suppose you’re watching a regular old Sunday afternoon NFL game, and you and a friend just put down $110 each on different teams to cover. The two of you bet a combined $220, but the winner will only get $210 back thanks to the odds.

So, to calculate the vig you take this difference pocketed by the sportsbooks ($10) and divide it by their total payout ($210). This means the vig on any even-money bet is 4.76%.

How Does Positive EV Betting Work?

EV sports betting, also known as +EV betting, isn’t an exact science because of the inherent subjectivity of wagering on sports. Yes, you can compile years of historical data and advanced analytics to get a loose idea of what the probability is, but, as any sports fan knows, nothing is guaranteed on any given night.

But, that doesn’t mean you can’t try. EV betting is all about using your own data, research, and sports knowledge to find odds that you think can be exploited. This can range from more general trends (ex: NHL road favorites playing a team that missed the playoffs the previous season) to thoroughly analyzed single-game opportunities.

Once, you have a well-researched idea of the actual probability. Use this formula to find the EV of your potential bet.

(Probability of winning x Potential Profit) – (Probability of losing x Potential Loss)

And always remember to take the vig into account. If your positive EV isn’t enough to overcome the sportsbook’s built-in profit margins, it’s not a bet worth making.

How to Read Positive EV Odds

To understand how to read Positive EV odds, let’s use the simplest example possible, flipping a coin. The odds on this coin are set at fair market value, so +100 for heads and also +100 for tails. The +100 represents the amount of money you’ll earn with a $100 bet, so even money bets will give you an equal $100 return.

But, after doing some research, we find that the coin being used is actually slightly weighted towards heads, making the probability jump from 50/50 to 55/45. With this knowledge, we decided to play $100 on tails. Now, we can calculate the Positive EV of this bet with the formula we discussed above.

(.55 x 100) – (.45 x 100) = +10

With a positive EV of 10, that means we are expected to make $10 for every $100 we bet on this weighted coin. Obviously, positive expected value won’t be anywhere near as obvious in sports betting, but this gives you a basic idea.

Now, let’s talk about the different types of odds you might run across while betting on sports.

What are Fractional EV Odds?

Fractional odds are what you’ll most likely find when betting in the UK. As the name suggests, fractional odds are expressed in the form of a fraction, with the first number representing your potential payout and the second representing your initial bet.

For example, a bet at 2/1 odds means that you’ll earn $2 in profit for every $1 you spend. With fair-market value (no vig), the odds of this bet should be 1 in 3, or 33%.

What are Decimal EV Odds?

You’ll find decimal odds in many European countries, and they offer the most straightforward approach to displaying probability. Unlike fractional and American odds, decimal odds in plus EV betting show your total return, including your initial wager.

Using the 2/1 odds example from last time, that same wager displayed in decimal odds would be 3, the total of your initial investment (1) and potential profit (2).

What are American EV Odds?

The standard across all the most popular American sportsbooks including FanDuel and DraftKings, American odds are the most common type you’ll see in betting on EV.

American odds are based on bets of $100. So, if the odds of a bet are +200, that means you’ll win $200 for every $100 you bet. When the odds are negative, the odds represent the amount you need to bet in order to make $100 in profit. So, if the odds are -200, you’ll need to wager $200 to earn $100 in profit.

Calculating Expected Value

Now that we understand a little bit about expected value and how it works, let’s practice calculating it with a real-world EV betting example. Below are the odds and implied probabilities for the opening game of the 2023-24 NBA season on FanDuel.

Notice that the implied probability adds up to 104.18%, meaning that the vig is 4.18%. Let’s say we put down $50 on the Nuggets to win. Time to plug this into the EV betting formula and see what we get.

(.6970 x 21.74) – (.3448 x50) = -2.09 EV

This is an example of a negative EV bet, which is what you’ll basically always find when strictly looking at the lines set by the sportsbook. Based on the implied probability offered by the sportsbook, you’re expected to lose $2.09 for every $50 you bet on the Nuggets to win.

To get a positive EV, you would need to be slightly more optimistic about the Nuggets than the consensus. Let’s say you do the research and statistical analysis to determine that the Nuggets are likely to win 75% of the time. Based on your own probability, things are looking a lot better.

(.75 x 21.74) – (.25 x 50) = 16.305 – 12.5 = +3.81 EV

This means that, based on your own analysis, you’re expected to win $3.81 for every $50 you bet on the Nuggets.

Are Special Tools Needed to Determine Positive EV?

To calculate a positive EV, you don’t need anything special. Since positive EV is based on a simple mathematical formula, all you’ll need is the calculator on your phone to determine the EV of any particular bet, or just use a positive EV betting calculator online.

But, you’ll need more than that to find the important data that will lead you to positive EV betting opportunities. Stat sites like Sports Reference and Stathead, along with advanced analytic hubs like Opta and FanGraphs, are resources that you’ll need to use to find Positive EV bets on your own.

Positive EV Betting Strategies

When it comes to our expected value betting picks, there are a few key strategies we utilize to make sure that no stone is left unturned.

Below are three things we do to help find consistent possible profit opportunities through EV bets.

Analyze Every Level

One thing that people often forget is that positive EV betting can follow trends from the macro to the micro and everywhere in between.

For instance, you could find a positive EV betting trend that applies to a wide range of matchups. An example of this would be short road underdogs (+130 or less) in the NHL who are coming off a win. This is a very general trend that can apply to dozens of games each year, but one that over a long period of time had produced solid profits. Or, you could analyze the minutiae of one specific matchup between two teams to find a potential EV+ opportunity.

At Overtime Heroics we look at EV betting trends on all levels, so you never miss an opportunity for some easy potential profits.

Mix Past Results and New Additions

Looking at past results will only take you so far when searching for positive EV betting opportunities. In major American sports like the NFL, MLB, and NBA, rosters can fluctuate wildly in between seasons, to the point where head-to-head matchups really don’t have much relevance farther back than a handful of years.

To really get the full picture, our experts combine recent head-to-head data with careful analysis of any new additions to find the best EV+ opportunities. Accurately predicting how an offseason addition will impact their new team ahead of time is one way we stay on top of the game.

Plunging Into the Data

Analyzing data is crucial in expected value betting. Our experts delve deep into statistics, including surface-level metrics like batting averages or shooting percentages, and more advanced analytics like expected goals (xG) or Fielding Independent Pitching (FiP).

These numbers provide insights into player and team performance, allowing us to identify profitable betting opportunities backed by data, not just intuition. Our commitment to a data-oriented approach ensures that our picks are well-founded and not based solely on gut feelings, giving you a solid foundation for your betting decisions.

How Important is EV when Betting on Sports?

Taking the time to calculate the expected value of any given bet is a great way to not only better understand the numbers behind sports betting, but also to get a better understanding of just how confident you need to be for each bet you make.

Below are three reasons we think EV is important when it comes to sports betting.

Bankroll Management

In the world of sports betting, Expected Value (EV) and effective bankroll management are like two sides of the same coin (not the weighted coin we discussed above). Understanding EV is paramount for any bettor as it quantifies the probability your bet needs to clear for success.

By meticulously calculating EV, you can make informed decisions, steering clear of high negative EV bets that can deplete your bankroll. In the long run, this approach not only safeguards your funds but also ensures you remain in the game, ready to seize positive EV opportunities when they arise.

You Track the Lines

As you become proficient in EV in sports betting, you’ll find yourself closely monitoring different odds and lines, searching for potential opportunities. This vigilant line tracking not only enhances your potential profitability but also deepens your comprehension of how sportsbooks react to various news and events.

Over time, you’ll start recognizing patterns in odds adjustments, further refining your betting strategies.

Find Hidden Value

When you’re well-versed in EV, you gain the ability to identify those elusive positive EV bets. By knowing the precise probability associated with each possible outcome, you can distinguish bets where the odds offered by bookmakers surpass the actual likelihood of occurrence.

Armed with this knowledge, you can focus your betting efforts on the most valuable opportunities, maximizing your potential returns.