How Does Gambly Calculate a Bet’s Edge?

While Gambly doesn’t take a direct stance on games, we do calculate the edge–or expected ROI–for most (but not all) bets. Typically, the larger the market, the more likely we are to have the expected edge.

These edges come via Unabated, with whom we partner for real-time, comprehensive odds. In simple terms, these calculations are a comparison of the current line on a bet at any given sportsbook and the consensus of market-making sportsbooks. 

Unabated (and Gambly) don’t take a viewpoint on games outside of market data, meaning this approach is top-down and sport-agnostic. For example, if DraftKings has the odds of a certain event at -110 and all other books are at -120, it’s likely that DraftKings’ line is off. But not all sportsbooks are created equally–some are sharper than others–and Unabated uses a weighted combination of each market-making book’s historical accuracy to calculate what the actual vig-free line should be, or the true odds. These formulas are sport-specific, meaning the “source of truth” for baseball is different than basketball, for example.

By comparing the current odds to a probable “true line” based on current market structure, it’s possible to calculate a bet’s expected ROI. If the vig-free true line based on market-making books is even money and FanDuel has that bet at +110, we can calculate the anticipated edge (even money is of course a coin flip, and getting paid +110 on each bet equates to a 5% edge).

There’s some nuance to how the “true line” is calculated–certain sportsbooks get different weights, adjustment for recent line movement, and so on–but in a nutshell, that’s how things work. A pure market data-driven approach.

When a bet is +EV–it has a positive expected ROI–we signal that with the edge calculation shown in the top right corner of the bet within a widget. When the EV of a bet is negative, we don’t show anything.

Note that the term "best" in this query instructs Gambly to look at all market data and return the bets with the highest anticipated ROI.

Of course, the Gambly edge calculations are simply a rough guide to help you find profitable bets based on the current market. Ultimately, our aim isn’t to be a picks service, but rather to do everything we can to help pair you with the bets you’re looking for.

Play around with Gambly and see what +EV bets you can find.