Introduction To Positive Expected Value Sports Betting

Sportsbooks set their odds independently, meaning that each uses their own algorithms to determine the listed odds for a given market. Since their algorithms, particularly for larger sportsbooks, are very efficient you will generally see similar odds across all sportsbooks - we call this consensus. However, there are select instances - particularly shortly after injury news or other information becomes public - when one sportsbook offers odds that reflect a much higher payout than the conesus odds. Betting such a market may be considered “positive expected value” which simply means that the payout offered is greater than the true odds of the outcome occurring.

Take the above +EV wager as an example. Fanduel, DraftKings, and Caesars all have their odds priced around even payout. The column with our logo shows the no-vig odds (simply the odds with the house edge taken out) of the market based upon what our algorithm has calculated to be the market average of “sharp” books, which will be touched on in a later section. According to our algorithm, the no-vig fair odds for the “over” is +105. This means that, assuming our algorithm is accurate, in the long run you’d expect to break perfectly even by betting this wager at an odds of +105. However, since the odds on BetRivers are +116, the actual payout is higher than the breakeven payout. Thus, this is an example of a “positive expected value” bet. By betting on markets like this in the long run (1,000+ times) you can expect to be profitable - in this specific case at a rate of 5.5%.

It is important to note that this is a statistical edge in the long run, but it says nothing about short-term results. Despite the fact that you have a 5.5% edge over the house, Jayson Tatum may still get under 8.5 rebounds and so you may lose the bet. In the long run however, if you were to bet on this sort of market thousands of times, if you truly have a 5.5% edge you are just about guaranteed to be profitable.

One more important thing to note is that some books are “sharper” than others. This simply means that they are quicker to change their odds after injury news or other information becomes public. Our algorithm takes this into account. For main lines, Pinnacle and Circa tend to be sharpest, while for player props FanDuel tends to be sharpest. This varies by sport/market/time, and our algorithm takes this all into account - but it is something important to be aware of.