What Is Vig? The Tax Inside Every Betting Line
Flip a fair coin. Heads and tails are each worth +100. Now open your sportsbook: the same coin flip is priced −110 on both sides. That ten dollars of difference has a name, and it's the reason most bettors lose slowly instead of winning slowly.
The cleanest scam in gambling (and it's legal)
At −110 you risk $110 to win $100. If the book takes $110 on heads and $110 on tails, it collects $220 and pays back $210 no matter what lands. The missing $10 is the vig (the juice). In probability terms: −110 implies a 52.4% chance, and 52.4% + 52.4% = 104.8%. Real probabilities sum to 100%. The extra 4.8% is the tax.
What the tax costs at each price
The juice moves with the number after the minus sign: −105 is a 2.4% tax, −110 is 4.8%, −115 is 7.0%. That's why line shopping matters: moving from −115 to −105 isn't cosmetic, it cuts your tax by two thirds. And it compounds: a $100 bettor firing five −110 coin flips a week donates about $1,180 a year without ever making a bad pick.
Moneylines hide it better
A line like −150/+130 looks innocent because the sides differ. Devig it and the −150 side is really −138, a 58.0% true chance dressed up as 60%. You're paying two full points of probability for the privilege of betting. That gap is invisible until you strip the juice, which is the whole point of a devig calculator like Actual Odds: paste the market, see the fair price, and know exactly what you're paying.
The takeaway
You can't make the vig disappear. You can know exactly how big it is on every bet, pay the smallest version of it, and only fire when a boost or promo pays you back more than the tax. Start with which devig method to trust.