Expected value (or EV) is a term you hear a lot in sports betting, as well as other forms of gambling. But what does it actually mean, and how do you find it? We've put together a quick introduction to the main concepts.
Positive EV (Expected Value) or +EV Sports Betting. What Does it Mean?
Expected value (EV) is the probability gap that exists between the expectations of the Sportsbook and the bettor. To understand the difference between a positive EV and a negative EV, let’s imagine a contest between two closely matched boxers. They have equal form and abilities and it’s hard to split them.
It’s basically a coinflip, and the odds reflect this. But you believe that Boxer A is much better than the Sportsbooks realize and you have a strong feeling that he will get the win. For you, it’s less of a 50/50 and more of an 70/300. In such cases, you would assign a positive EV (or +EV to Boxer A and a negative EV to Boxer B. After all, you’re getting a pay-out based on 50/50 probability for something you think is closer to 80/20. It’s akin to betting on Black on a Roulette wheel and then removing most of the Red segments before the wheel is spun.
Why Does +EV Matter in Sports Betting?
Sportsbooks have a lot of data at their disposal and they go to great lengths to make sure everything is accounted for. If a star player is injured, the odds may drop. If it’s going to rain and the QB rarely performs well in the rain, the bet lines will be tweaked accordingly.
However, they are not fallible. What’s more, all bet lines are impacted by market fluctuations. If everyone starts betting on a particular line, the odds for that line will drop as the sportsbook seeks to balance the books and ensure a profit regardless of the outcome.
You can take advantage of this as a sports bettor. Look for undervalued and overvalued bets, assign EVs to all of them, and then place your bets accordingly. EV is also very popular in the poker world, and you can use the same principles when betting on sports. If a poker player knows that only one card can improve their hand, and there’s only one card left to draw, they might be tempted to fold. But if there is $10,000 in the pot, they only need $250 to call, and there’s a 5% chance of success, it makes sense to bet.
After all, that’s a 1/20 probability for a potential 40/1 return. You don’t need to be good at math to know that’s a worthwhile wager.
Calculating EV in Sports Betting
To calculate the EV, you first need the implied probability. When calculating negative odds, use the following formula:
Odds + 100 * 100
For positive odds, this is the formula to use:
100 / (Odds + 100) * 100
Convert the final number into a percentage to get the implied probability.
In the above examples, odds of -300 and +265 would give us an implied probability of 75% and 27.39% respectively.
The rest is down to you. If you determine that the -300 bet has a 90% chance of success, it’s a positive EV wager. If you think it’s more of a 50/50 contest, it’s a negative EV wager and the alternative option may be better.
Using EV to Find an Edge in Sports Betting
Once you know the implied probability, the edge is very easy to calculate. Simply add the two probabilities together and then subtract 100. In the above example, 75 + 27.39 is 102.39, and if we subtract 100 we get 2.39. This means that the edge for this particular betting line is 2.39%.
Should I Consider EV for my Sports Bets?
If you are serious about sports betting, you should definitely consider the expected value of the bets that you make. In the beginning, it helps to run the numbers and seriously think about whether you’re getting positive or negative EV. After a while, it will all become second nature and simply glancing at the betting lines will be enough to tell you the EV.
How to Find EV Bets?
Here are four tips for finding good EV bets.
1. Shop the odds and lines early. Our Odds Comparison tool is a great place to do this The most value can be found when the lines first open, as they haven’t had time to adjust under the influence of other bettors. In-play betting is another great way to find good EV bets, as the lines are constantly changing and if you’re watching the game and have a good read, there is a lot of value to be had.
2. Remove all emotion from the equation, which means not betting on your favorite team. Next, you should check the bet lines on a regular basis to look out for opportunities.
3. Here is the hack, you can just use our Best Picks page. We have built an algorithm that uses advanced data monitoring and analytics to identify +EV picks. It aggregates the odds and line movements of the most advanced sportsbooks in the world to calculate what it deems the ‘perfect odds’ for every matchup. When the algorithm finds Odds by Legal US Sportsbooks that it determines offer value relative to it’s perfect odds, it recommends the bet.