When betting on sports, the idea isn’t to bet on the team that you believe will win the game or cover the spread. Since the market odds will likely reflect the outcome of the match, there’s no value to be derived by taking this approach. Instead, to profit over the long-run, sports bettors must hunt for odds with positive expected values (+EV). In this article, we’ll describe what a positive expected value is and how you can use this to your advantage to meet your ultimate goal of betting for value.
Value betting exists when you place a wager on a match with a positive expected value. +EV is determined by comparing the odds of a match that you locked in at versus the closing odds of a match, that is, the odds of a match right before the match begins. This can be illustrated using two simple examples, one surrounding the moneyline (straight-up bets), and the other with the spread.
Columbus in 4 was set at +4651, an implied probability of 2.10%.
NY Islanders in 4 was set at +1808, an implied probability of 5.24%.
— Rob Pizzola (@robpizzola) April 16, 2019
To keep things simple, suppose the New York Yankees are playing the Boston Red Sox, with the moneyline odds being:
NYY +120 or 2.20
BOS -150 or 1.67
Let’s also assume that you believe that the game is pretty much a toss-up. This means that you believe the Yankees have a 50% chance of winning, while the Red Sox also have a 50% chance of winning. In this case, there’s value in taking the Yankees at +120 or 2.20. Since you’ve implied the Yankees’ probability of winning at 50%, the odds for the Yankees to win the game should only be +100 or 2.00. However, the market lists the odds at +120 or 2.20, resulting in a +EV. Herein lies value.
Now, let’s illustrate value in terms of the spread. Suppose the New England Patriots are playing the Cleveland Browns, with the spread being:
Let’s also assume that you believe the Patriots will definitely win by more than one touchdown. However, the spread for the Patriots is currently at -7.0, which indicates that the markets believe that the Patriots will win by only one touchdown. If you believe that the Patriots will win by more than one touchdown, the spread for the game should be NE -7.5 or higher, as high as possibly NE -14.0. In this case, there is also +EV, since the sportsbooks are implying that the Patriots will win by one touchdown in a relatively close affair while you believe that the Patriots will basically steamroll the Browns.
By betting for value, you’re increasing your odds of profiting over the long-run. Over a small sample size of bets, variance will have a significant impact on your results, either in a positive or negative manner. However, with more and more samples to draw from, you’re able to significantly decrease the impact of variance on your results, and luck is replaced by skill. As such, only sports bettors who are able to beat the vig-free closing lines at the sharpest sportsbooks will end up profiting over the long-run. Even if you don’t believe a team will be able to win the game but there’s value within the game odds, this represents a sound bet, and if you maintain these types of bets, you’ll surely profit over the long-run.