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Updated: Apr 24

Quick Read

Ever been dumbfounded by how exact a spread or total line was?

  • Sportsbooks use statistical models to convert massive amounts of data into understandable lines and odds

Ever wonder how sportsbooks make their money? Vig

  • While converting this data into odds, sportsbooks also include their own fee (juiced odds)

One of the most common examples of vig is with the spread being -110 / -110 on both sides

  • Originally the data had generated a spread line that was a “50/50” bet

  • What should’ve been +100 / +100 on both sides is then changed to -110 / -110

  • This fee (~5%) makes it very difficult to ever be a profitable bettor

Below I’ll show how sportsbooks use vig to guarantee profits as well as a method for removing this vig so we can see the fair odds

  • DYOR, never bet anything you can’t afford to lose



This a sportsbooks’ lines & odds for the Phillies vs. Braves game

To see vig in action let’s look at two scenarios...

In scenario 1 we can see that the Phillies (+1.5) covered the spread and Bettor A wins

  • Bettor A profits +$9.09 ($10.00 @ -110)

  • Bettor B loses -$10.00

In scenario 2 we can see that the Braves (-1.5) covered the spread and Bettor B wins

  • Bettor A loses -$10.00

  • Bettor B profits +$9.09 ($10.00 @ -110)

We can see that there’s a net loss of -$0.91 regardless of the outcome

  • Where’d that money go? The sportsbook (vig)

While -$0.91 may seem insignificant on its own, this fee (~5%) on every bet means we as bettors need an ROI of 1.05 (105%) to break even

  • While research and experience is important when making our picks, it’s difficult for bettors to consistently find this 5% edge since sportsbooks already set their lines with extensive data analysis and modeling


Finding the Fair Odds

We can use a sportsbooks’ odds (once we remove the vig) to see what their data and modeling says about a game

Let’s plug the sportsbooks’ odds into the no-vig calculator


Braves -1.5 @ -110 ➡️ +100
Phillies +1.5 @ -110 ➡️ +100


Over 8.5 @ -105 ➡️ +104
Under 8.5 @ -115 ➡️ -104


Braves @ -180 ➡️ -164
Phillies @ +155 ➡️ +164

We can see that the fair odds are identically opposite and total to zero (-164 / +164)

  • Odds that total to zero allow for zero sum bets where no money is lost to vig

  • Every bet on BettorEdge is zero sum

Thank for Reading!

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