EV+ Betting

Ready to put +EV betting into practice?

Understanding expected value is step one. The hard part is applying it: finding lines where a sportsbook has actually mispriced the odds means comparing thousands of markets against a devigged sharp benchmark, every minute, across every book.

That’s exactly why we built BettingTips.com, a +EV betting tool that scans 100+ sportsbooks in real time and surfaces positive EV bets with the exact edge percentage and a recommended stake based on Kelly staking. Every pick it flags is graded and published, wins and losses included.

Want the concepts explained from the ground up first? Read our guide: What is +EV betting?

Understanding Expected Value (EV) in Sports Betting

While it can be somewhat dangerous to view sports betting as an investment, the objectives of gambling and investing are similar: use your money to make more money. To do either effectively, you must be able to understand whether the opportunities you’re considering have value in your favor.

What Is Expected Value (EV)?

Expected Value (EV) is a mathematical calculation that determines the potential profitability of a wager over time. It represents the average amount a bettor can expect to win or lose per bet if the same wager were placed repeatedly under identical conditions.

A positive EV (EV+) indicates a bet with favorable long-term returns, while a negative EV (−EV) suggests a bet that will likely result in losses over time. Even if a wager has a high probability of success, it may still have a negative EV if the potential payout does not justify the risk.

Value Bets

You’ve likely heard the term “value bet” used to describe a betting outcome; simply put, it refers to any wager where the expected likelihood of a given wager is greater than the odds posted by a bookmaker would indicate.

Professional gamblers are experts in finding value bets, but learning how to identify betting value is important for casual bettors too. Doing so will help you to win more money over time as you continue to gamble, assuming you are successfully able to successfully calculate the EV.

EV+ Betting and Line Shopping

EV+ betting also lends itself to odds shopping and line shopping, both of which involve checking multiple sportsbooks to see which offers the most favorable lines for the markets you’re backing. The goal should always be to find scenarios where you’ve maximized your potential profits while minimizing the risk you’re taking on.

Using American odds as an example, you may see a line of -150, +100, -225, or +400. All of those numbers tell us something about the likelihood of a given outcome.

How Sportsbook Odds Reflect Probability

In general, when an online sportsbook shows a “+” symbol in front of the odds number, the outcome is considered less likely to occur, while the inverse applies when a “-” sign is present. However, these symbols can flip for a given line or outcome based on a variety of factors, including the number of wagers placed on either side, the amount of money wagered on given outcomes, matchup analysis, injury reports, and weather conditions, to name a few.

As a result of these factors, sportsbooks often have slight differences in their odds and line calculations to generate a profit regardless of the outcome. Exploiting these variances will increase the EV of your wagers leading to an increased return on your stakes and greater profits over time as your bets hit.

Positive vs. Negative Expected Value

As mentioned above, the calculated expected value can yield three results: positive (EV+), negative (EV-), or even value (EV=). EV+ bets should be played when you deem the value is worth your financial investment while EV- and EV= bets should be avoided.

For example, a wager with +100 odds is considered to have a 50% probability of either outcome. In this case, if you calculate the probability of that outcome is greater than 50%, you’ve found an EV+ wager; if it is less than 50%, you’ll have an EV- scenario and should avoid the wager.

However, sportsbooks also have a fee that is calculated into the odds known as the vigorish, or “vig.” The vig at U.S. bookies is typically between 3-8%, meaning the posted odds don’t automatically correlate with the expected win percentage.

Additionally, positive and negative expected values are relative terms and shouldn’t automatically be considered when the likelihood of winning is >50%.

As another example, let’s say the sportsbook lines indicate a 65% chance of Team A winning a game but your research leads you to believe Team A only has a 60% chance of winning. This difference of -5% means you would concede betting value in placing a wager; furthermore, despite Team A having a >50% chance of winning, the overall value of that bet wouldn’t make it worth your financial risk.

The ultimate goal of EV betting is finding scenarios where you have both a high expected probability of winning your wager and a high EV+ total after calculating both figures.

How to Calculate Expected Value in Sports Betting

Let’s take a look at a real-world example using the odds from Super Bowl LIX. The moneyline odds the day after the Conference Championship Games had the Kansas City Chiefs at -124 and the Philadelphia Eagles at +106.

Using those examples, each team’s implied chance of winning would be:

• Kansas City Chiefs: 124/(124+100) = 0.554 or 55.4% implied chance of winning
• Philadelphia Eagles: 100/(106+100) = 0.485 or 48.5% implied chance of winning

Notice that these percentages add up to 103.9%, though the true probability can only reach a combined 100%. This is because of the vig percentage, which in this case is 3.9%.

Using these numbers, you can calculate the EV for each line by subtracting your calculated percentage for each team to win from your projected win probability as you research the matchups.

The formula for calculating Expected Value is:

((Probability of Winning) X (Amount Won Per Wager)) – ((Probability of Losing) X (Amount Lost Per Bet))

Keep in mind that each bettor will use a different formula to calculate their projected win probability. For example, ESPN’s Matchup Predictor gave the Eagles a 56.1% chance to win, conversely, FoxSports.com gave the Chiefs a 55.6% chance to win.

Using these projections and a $100 stake amount, ESPN’s projected win percentage would indicate an EV on an Eagles wager of:

((0.561) X ($106)) – ((0.439) X ($100)) = ((59.466) – (43.9)) = $15.566 or $15.57 when rounded.

Using that same formula, ESPN would have the following EV for a $100 wager on the Chiefs:

((0.439) X ($80.65)) – ((0.561) X ($100)) = ((35.405) – (56.1)) = -$20.695 or -$20.70 when rounded.

But what happens if we use FoxSports’ implied win percentages?

For the Eagles, we get:

((0.444) X ($106)) – ((0.556) X ($100)) = ((47.064) – (55.6)) = -$8.536 or -$8.54 when rounded.

For the Chiefs, we get:

((0.556) X ($80.65)) – ((0.444) X ($100)) = ((44.84) – (44.4)) = $0.44

Taking this a step further, using the implied win percentages from the sportsbook where we got the odds, the following EVs would apply:

For the Eagles:

((0.485) X ($106)) – ((0.515) X ($100)) = ((51.41) – (51.5)) = –$0.09

For the Chiefs:

((0.515) X ($80.65)) – (0.485) X ($100)) = ((41.535) – (48.5)) = -$6.965 or -$6.97 when rounded.

Let’s put all those numbers into a table to help us determine where the betting values fall for each outcome and see what they suggest to do:

This is why we always advocate for conducting your own research into matchup analytics before making your wagers. The above examples show either team could be a value bet depending on what you determine each team’s likelihood of winning would be; it also shows relying solely on the sportsbook odds results in bad betting value for either outcome.

Interpreting Odds and Implied Probabilities

To calculate the implied probability while sports betting, you must first identify whether the lines you’re backing have a “+” or “-” symbol in front of the odds. You can use our betting odds converter if you don’t want to do this manually.

For lines with a + symbol, the formula for calculating the implied likelihood of winning is:

100/(Odds + 100)

For lines with a – symbol, the formula for calculating the implied likelihood of winning is:

Odds/(Odds + 100)

Because odds can vary by sportsbook, and because of different vig percentages, we recommend checking with multiple bookmakers to determine a more accurate implied probability. Once you feel comfortable with an average implied probability, you can use that total to calculate the EV, or use it as a reference point for your own calculations.

Identifying EV+ Betting Opportunities

When identifying EV+ betting opportunities, you’ll have some flexibility in deciding your parameters for betting value. In the example above, is a positive EV of $0.44 enough to back the Chiefs using FoxSports’ projected model, or are you better off backing the Eagles using ESPN’s win probability numbers?

You don’t need to back a wager solely because it has a positive betting value, because again, betting value is relative to the likelihood of winning. Outcomes with a slim likelihood of winning could have a high betting value total, but without a reasonable probability of winning, the bet still may not be “worth it.”

This especially applies to futures wagers, where the long-running nature of the wager type can lead to favorable odds early on that enhance the value because of a high rate of profit on a winning wager. However, you can still calculate EV while in-play wagering or when placing your pre-match bets to determine if the wagers are worth your time and money.

Tools and Resources for EV+ Betting

If math isn’t your forte, you may find it easier to use our EV+ betting calculator to plug in the numbers, giving you a quick assessment of your wagers to see if the value lines up.

You may also want to consider an odds comparison tool to quickly determine which sportsbook is offering the best odds for the markets you want to back. While these differences may be subtle, capitalizing on those differences leads to larger returns over your betting career.

Finally, there are win probability modeling tools available that weigh a variety of factors to help determine the likelihood of a given betting outcome. While these tools may come at a cost, successful wagering can help to offset the cost of that investment.

Conclusion

While any bet with an EV+ value can be considered a “value bet,” it’s up to you to decide on an acceptable EV range for placing your wagers. It’s ok, and encouraged, to adjust as you go if you are figuring out what works best for you and your gambling goals.

Furthermore, keep in mind that there will be many instances where the best bet is no bet at all. It is ALWAYS better to walk away from the sportsbooks and wait for a better opportunity to place your wagers than to make ill-advised bets.

Before placing your next wager, give Bettor In Green’s EV calculator tool a shot and see just how valuable your wager may be!

Good luck, have fun, and always gamble responsibly!