EV betting explained: how expected value helps you make smarter sports bets

07/07/26

Contents:

EV Betting: What it is and Why You Should Care.
Understanding expected value in sports betting
The relationship between odds and probability
Positive EV vs negative EV
Putting EV into Practice for Sports Betting
EV betting example
Calculating expected value with real odds
What makes a bet positive EV?
Why do professional sports bettors focus on value and not on winning individual bets?
Tools used to identify positive EV opportunities
Positive EV betting vs arbitrage betting
Common sports where EV strategies are most popular
How bankroll management supports EV betting
How closing line value relates to expected value
Frequently asked questions
What is EV betting?
How do you calculate expected value in betting?
What is a positive EV bet?
Do professional bettors use expected value?
Is positive EV betting guaranteed to win?
What’s the difference between EV betting and value betting?

If you want to bet smart then you have to stop betting on luck and start using the EV betting method. As EV stands for expected value it is the quantitative process of finding mispriced sportsbook lines in order to earn a long-term mathematical edge. By mastering the course, you will be able to stop betting in a reckless and futile way and switch to wagering as you would with any other investment. In the following tutorial you will find the necessary information about EV as well as the corresponding calculations in order to successfully apply the explained EV method in practice.

EV Betting: What it is and Why You Should Care.

In the majority of situations, most gamblers take a wager on a sporting event because they believe that their chosen team or player will achieve victory in the match. EV betting however is very different from this, in that it’s based purely on mathematical statistics that enable us to calculate the Expected Value of any bet in order to see if the returns that are on offer contain any value for us, or if we are likely to lose in the long term.

Why is EV betting so important for the majority of wagers put on in the sports betting market? There is only a very thin margin between positive and negative expected value for the wagerer. The sportsbooks have included a huge amount of margin into the odds that are put on to the various markets for a wager. For example, if you were to look at the odds for all the possible outcomes for a single match then the sum of the implied probability for the outcome of all the individual wagers for a match would be greater than 100%. This means that in most cases you would be mathematically expected to lose in the long term if all you were doing is picking the winners of wagers for sports events. However, for the sports bettor that uses the application of expected value to their systematic sports betting system then there will be many instances where they have found a wager where they have an edge from time to time.

Understanding expected value in sports betting

The Expected Value (EV) of a bet is the average amount of net gain/loss per bet, assuming an infinite number of same bets. In simple terms, it’s how much you can expect to win/lose on average, per bet.

These numbers are used to calculate the expected return from any given wager. Your bet size, the potential payout, and the estimated true probability of the outcome all have to be entered into the equation in order to find your expected return from any given wager. This is the core of EV betting. In order to find +EV wagers, you need to use these numbers in the equation to determine how much you can expect to win or lose on average per wager. This will enable you to make the most informed wagers in the long run.

The relationship between odds and probability

Sportsbook odds (whether they be in American odds format or decimal odds format) are more than just the amount of money that you will receive for your wager if you were to win. The odds are also the bookmaker’s implied probability of the occurrence of the event(s) that you are betting on. In order to apply the expected value formula above, the odds that are posted by the sportsbooks must first be converted to percentage format.

To find the probability of an event happening when betting with American odds, two different formulas can be used. The first formula is used when the money line is a positive number, and the second formula is used when the money line is a negative number. For decimal odds, there is no formula to find the probability of an event happening and the odds are simply divided by 1.

When finding the odds for a given event, there is already a margin, also known as the vigorish or overround, included in the bookmaker’s odds for the event. This margin must be subtracted from the odds in order to uncover the true fair odds of the event. In order to accurately remove the margin from the odds of an event, the bettor must find two lines that are the direct opposite of each other (i.e. correlated lines). When these lines have been found and the margin has been removed from both lines, the expected value (EV) for both lines can then be accurately calculated.

Positive EV vs negative EV

A Positive EV Bet Has A Mathematical Edge: When running thousands of iterations of a bet, consistently wagering on +EV positions will result in a net profit. That means all of the variances of the individual losses will be overridden by the +EV statistic. The one thing that matters when determining whether or not a wager is profitable in the long run is the Expected Value Statistic. And as you can see from the example above, when running thousands of iterations, the end result of +EV wagers will be a net profit.

Now for how EV can be used in practice. EV or expected value in sports betting (EV betting explained) needs to be calculated by using the sportsbook’s odds and your own knowledge or research of a game to work out the true probability of an event. This is known as the betting margin or the vigorish. If your calculated true probability is greater than the bookmaker’s odds imply then you have a edge or EV in your favor.

Putting EV into Practice for Sports Betting

A great place to start with EV is to compare a sportsbook’s implied probability of a given outcome with the true probability of that same outcome as calculated by a bettor’s highly accurate model of that outcome. In cases where the true probability of a given outcome calculated by a bettor’s model is greater than that implied by the odds at a sportsbook, that bettor has identified a mathematical edge.

Figuring out EV is a very simple process. First off you have to figure out how much you are wagering. Then you figure out how much you are making in terms of profit. After that you take your estimate of true probability (internally modeled) and your best estimate of loss percentage (internally modeled) and apply it to the following formula:

EV = (Probability of Winning × Net Profit) – (Probability of Losing × Stake)

This will tell you the average amount of money that you expect to make or lose over time by placing the same type of wagers repeatedly.

EV betting example

Using EV calculations in normal wagers can prove to be a very powerful tool for determining the edge of the line. A simple calculation can highlight even the smallest of edges available within the market, and as said before, even the smallest of amounts of money can be very profitable when they are compounded over a long period of time.

Calculating expected value with real odds

Here is an example using a specific wager from a recent game. The NFL moneyline for the Los Angeles Rams was listed at +150 at several different sports books. Therefore a $100 bet would return $150 plus your initial $100 for a total return of $250. Now let’s apply the expected value calculation using the true probabilities for winning and losing derived from the book’s content and from a de-vigged sharp sports book. First, the winning true probability for the Rams of 45% is multiplied by the net profit of $150 for a result of $67.50. Next, the true probability of losing for the Rams of 55% is multiplied by the initial stake of $100 for a result of $55. This results in an expected value of $+12.50 for every $100 bet for this specific proposition. In other words, for every $100 wagered on this exact proposition the gambler would on average realize a net gain of $12.50 over the long run.

You can find the true probability of a team winning a game by using a lot of statistical data, or you could look up a “de-vigged” odds at a sharp sportsbook that has already set the lines at true odds. The “de-vigged” odds are the odds with the bookmakers’ built in vig (margin) already removed. Once you have come up with a true probability of a team winning a game that you are betting on, then you have to come up with an estimate of the true probability of the teams’ alternate scenarios.

Applying the expected value formula:

EV = (0.45 × $150) – (0.55 × $100)
EV = $67.50 – $55.00 = +$12.50

Using the numbers above, the expected value of this wager would be $12.50 for every $100 wagered. This means that for every $100 that you bet on this NFL moneyline wager, on average you can expect to make back $12.50 over the long run.

What makes a bet positive EV?

The reason a bet would have a positive expected value is because the true probability of an event happening is greater than the implied probability of that event happening. So in effect the bettor is making a profit because the event’s price in the betting markets is greater than the actual risk of the event happening. To identify value the sharp bettor must be aware of all of the lines for all of the wagers in all of the betting markets and then shop for the best lines for his wagers. The sharp bettor must also have an accurate assessment of the true probability of a wager to have a positive expected value.

Why do professional sports bettors focus on value and not on winning individual bets?

There is a common misconception among new sports bettors that having a good night of betting means that you won all of your wagers for the evening. In reality, having a good evening of sports betting has everything to do with your expected value per wager and very little to do with how many wagers that you did win for the evening. For instance, you could lose out a rather large percentage of your wagers for the evening and still turn in a very profitable evening, provided you were betting at a high expected value per wager for the wagers that you did lose for the evening. It is worth noting that the vast majority of wagers made by professional sports bettors of the sharp variety are expected to lose, however this does not mean that the individual placing the wager will lose money in the long run, as long as he or she is betting at a high enough expected value per wager.

Most people that bet on sports have the mindset that they must win more bets than they lose in order to make money betting on sports. This is easy to believe, because most people understand winning and losing. What most people do not understand is EV or expected value. In simple terms a bet with negative expected value loses money and a bet with positive expected value wins money. Therefore, a professional sports bettor is only concerned with finding the most amount of value in the lines for individual wagers and betting those wagers in hopes of making as much as money as possible in the long run. A bet that wins at negative expected value is lost and a bet that loses at positive expected value is won.

Tools used to identify positive EV opportunities

The only way to go through thousands of markets every day and assess whether they present any positive EV for a human, is through the use of computer software.

Utilizing odds comparison services are critical to any serious gambler. Odds comparison services will compare thousands of daily wagers from hundreds of ‘soft’ sportsbooks allowing the gambler to search through the plethora of betting markets with ease. The service will also perform line shopping on behalf of the gambler automatically searching for the highest available odds for any wager. By aggregating odds from all of the betting sites in the world, and doing all of the work for the gambler, the line shopping platform would calculate the expected value for each wager. Highlighting wagers with the highest value, these would be the ‘best’ wagers to place allowing the gambler to generate the greatest return for each unit of money wagered.

People using these types of line shopping platforms run software that scans hundreds of thousands of lines a day and identifies instances where a mispriced wager is available for its customers. In addition to the types of line shopping platforms that were previously mentioned, the serious bettor also relies on his or her own proprietary statistical models for estimating true probability of certain outcomes. Such a model could include a variety of different pieces of information. For instance, a model used for scoring in baseball could include historical statistics such as on base percentage and slugging percentage. A model used for outcomes in football could include historical performance in various situations. Weather could be a factor in various sports. There are countless different pieces of information that a model can incorporate in an attempt to arrive at the most accurate estimate of true probability.

Positive EV betting vs arbitrage betting

There are many ways to make money from price inefficiencies in sportsbooks, two of the most popular methods are Arbitrage Betting and Positive EV Betting. In this article we are going to go through the main features of both methods, starting with the risk profile of both and then we will go into more detail on each of the methods, highlighting the main differences.

Feature	Positive EV Betting	Arbitrage Betting
Risk Profile	The risk of the outcome of a bet, as with any other gamble.	The risk is effectively zero, but there are risks of other sorts (see below).
Probability	Requires estimating true probabilities.	Does not require probability modeling; relies on price gaps.
Variance	High variance; losing streaks are mathematically normal.	Minimal variance if executed perfectly across sportsbooks.
Profit Source	Long-term mathematical edge over the market.	Immediate, guaranteed profit from opposing wagers.

Arbitrage betting is risk-free. However, it is extremely sensitive to price movements as well as to account limits held by bookmakers. Positive EV betting carries risk of losses as well as variance of outcomes of events for which a bettor places wagers. However, such type of betting has higher potential for scaling of profits in the long run.

Common sports where EV strategies are most popular

We typically see Value focused betting in markets that have a large amount of liquidity such as NFL, NBA, MLB and soccer. These markets have a large amount of historical data for a sharp bettor to analyze to find Value at soft books against the recreational bettor who is over pricing events.

On the other hand, in lower-tiered leagues, college sports, and prop markets the opportunities for +EV betting are huge compared to their more popular counterparts. The reason for this is the under-servicing of these markets by the bookmaker’s algorithm. Large, short-lived pricing errors occur in these markets that can be identified and capitalized on by a data-driven bettor.

How bankroll management supports EV betting

To some extent, having a positive EV helps to to counteract adverse variances and in the long run to guarantee gains. However, in the short term there is always a chance of incurring a net loss, even with a positive EV. This can be mitigated by the application of bankroll management to prevent ruin in the worst case scenario.

While a Positive Expected Value does not guarantee profit (because of variance), it does guarantee that the amount of profit one can expect to make from the Positive Expected Value is greater than the amount of profit one can expect to lose. In order to maximize growth, professionals use separate bankrolls for wagering and employ methods for calculating the amount to wager using dynamic staking methods such as the fractional Kelly Criterion, which correlates the amount to wager with the specific Positive Expected Value.

How closing line value relates to expected value

The closing line value (CLV) is a term often used in handicapping to describe the difference between the odds at which a player placed a bet and the closing line of the sportsbook’s lines for the event. The lines of most sports tend to get very efficient within a few days of the event date and thus the closing line is often viewed as being the true line of the event with the true odds for all possible outcomes of the event. If a handicapper finds wagers with positive expected value and places them before the line closes then he or she has found lines with CLV greater than zero. That is, the handicapper has identified lines where the true odds of winning are greater than the odds at which he or she placed the wager. In other words, the market has confirmed that the handicapper has found wagers with positive expected value.

Tracking Closing Line Value (CLV) can help a bettor in many ways. For starters, beating the closing line on a consistent basis shows that a bettor has a positive expected value on his wagers. This is because the CLV represents the final line of odds posted by all the books in the market, and thus it is a very accurate representation of the true probability of an event to occur. By tracking CLV, professional bettors are able to monitor their own performance and use it as a process metric. Whether or not they are up or down for the year is irrelevant; all that matters is whether or not they are beating the closing line, and thus the market.

Frequently asked questions

What is EV betting?

EV betting is basically betting with higher expected value than you believe the bet to have, and/or higher expected value than the sportsbook implies the bet to have. It removes the role of the sports analyst, and instead allows you to focus on finding the lines that have high expected value and are mispriced by the sportsbook.

How do you calculate expected value in betting?

The expected value calculation for each bet is the product of the bet’s estimated probability of winning and net value, and also the product of the bet’s estimated probability of losing and the total amount of money that you have staked on that bet.

What is a positive EV bet?

A positive EV bet is a bet for which the true probability of the occurrence of an outcome for a given event is higher than the implied probability of that event occurring in the odds at a sportsbook for that event.

Do professional bettors use expected value?

Pro bettors can rely on EV when evaluating possible wagers. Professional gamblers do not care about wins and losses over the short term. Rather, all of their research and time is focused on trying to identify possible wagers that hold a favorable expected value. In this way, they are able to determine and compare all of the wagers in the sportsbook to arrive at the best wagers in the long term, those with the highest EV and best expected return for the risk

Is positive EV betting guaranteed to win?

A positive EV bet is not a guarantee that you will win the bet in question. What positive EV betting guarantees is that the law of large numbers will make good on the expected value for you as you make more and more wagers.

What’s the difference between EV betting and value betting?

Value betting and expected value betting (EV betting) are terms that are used interchangeably in the gaming community to describe the practice of using expected value in betting. Value betting refers to betting to make a profit by taking wagers that have a higher return than their true probability of losing. The key to value betting is to identify wagers that have been mispriced by the bookmaker.

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