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# Optimal Bets | EV Explained

What does "Expected Value" mean for sports betting?
Written by
Jake Betz

Our mission at Optimal Bets is to increase the expected value for bettors.

Most bettors fundamentally misunderstand "expected value."

EV, short for expected value, is the most vital mathematical concept in sports betting. Understanding it will 100% make you a better bettor.

To illustrate EV using a flip of a coin, consider a situation where you flip a coin and win \$100 if it comes up heads and lose \$100 if it comes up tails. Since the probability of flipping heads and tails is equal to 50%, the expected value of the flip is:

Expected value = 0.5 * \$100 + 0.5 * -\$100

Expected value = \$50 + (-\$50)

Expected value = \$0

This means that, on average, you can expect to neither gain nor lose money from this coin flip.

Let's say the odds for both heads and tails are now set to -110, and you decide to bet \$110 on heads. If heads comes up, you win \$100, and if tails comes up, you lose \$110. The expected value for that bet would be:

Expected value = 0.5 * \$100 + 0.5 * -\$110

Expected value = \$50 + (-\$55)

Expected value = -\$5

This means that, on average, you can expect to lose \$5 for every bet you make.

There is a significant difference in calculating EV for a coin flip versus a sports bet.

With a coin flip, your expected win percentage (aka probability) for both heads and tails is known. It is 50%.

With a sports bet, your expected win percentage (aka probability) is unknown.

Before a sporting event starts, there is no way to know with 100% certainty what the exact win percentage of all possible outcomes is.

The best we can do is create models to guess the win percentages. And the better our models calculate the expected win percentages, the more profitable our bets will be.

There is a misconception in the sports betting community that "EV" betting is simply comparing lines/odds against the lines/odds at Pinnacle because they are widely known as the sharpest book. However, this is just one example of a model.

Optimal Bets leverages many different models to calculate win percentage and EV.

We created a proprietary model to approximate the win percentage for given player props. We'll save an in-depth dive into the model for another time, but here is how it's displayed in-app.

This player prop is O/U 26.5 points for Anthony Edwards.

Pinnacle is offering the best Over line at +112.

PointsBet is offering the best Under line at -115.

The value in blue is a projection from Rotowire (in this case) that Anthony Edwards will score 25.1 points.

The values to the right in red and green are the model's calculated expected win percentage. It expects the over to hit 49% of the time and the under to hit 51% of the time.

That value to the right is tappable. You can rotate through Win %, EV, and Bet Units by tapping them.

The over has an EV of +3%.

Expected value = 0.49 * \$112 + 0.51 * -\$100

Expected value = \$54.8 + (-\$51)

Expected value = +3.8%

An expected value of +3.8% is strong. In our app, we color code good as green, bad as red, and neutral as gray.