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
Example
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
Spread
Braves -1.5 @ -110 ➡️ +100
Phillies +1.5 @ -110 ➡️ +100
Total
Over 8.5 @ -105 ➡️ +104
Under 8.5 @ -115 ➡️ -104
Moneyline
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!