What Is Vig and How It Affects Your Long-Term Returns

The eye-in-the-sky sees everything. What it sees most often is the vig, sitting in the corner like a permanent house guest that nobody mentioned but everybody knows about.

Vig is commission. Juice. The cut the sportsbook takes for holding your money. If you bet $110 to win $100, you're paying a 10 percent vig. That's roughly -110 in betting notation. The sportsbook doesn't care whether you win or lose; they profit on the handle, the total amount wagered.

I worked the floor in 1987 when offshore books were the only option and the vig was negotiable. You could call up a shop in Costa Rica and argue down from 15 percent to 8 percent if you were betting large enough. The guys running those places were former casino people. They knew the margin. Now it's standardized. -110 for most point-spread bets. That's vig.

Why It Matters

Here's the part most sports bettors never calculate: to break even against -110 vig, you need to win 52.38 percent of your bets. Not 50 percent. 52.38 percent. That's the breakeven threshold.

Why? Math. If you bet $110 to win $100, and you win 52.38 percent of the time, your expected return over 1,000 bets is: (523.8 wins times 100 dollars profit) minus (476.2 losses times 110 dollars loss) equals about zero.

If you win 51 percent, you lose. If you win 52 percent, you're underwater. 52.4 percent puts you barely above water.

This is why professional bettors track closing-line value, not just wins and losses. Closing-line value is the margin between your probability assessment and the market's final assessment. If the market closes at -110 and you assessed it as -105, you've captured 5 cents of value per dollar wagered. Over 1,000 bets, that's real money even if your straight win rate is only 50 percent.

The Longer Game

I knew a guy who ran a small book in Vegas from 1989 to 2003. His entire business model was vig. He didn't try to pick winners. He balanced his sheets, moved his lines, and let the vig do the work. Over 15 years he made solid money without ever being a sharp bettor. He was just a competent book runner.

Now the sportsbooks use the same model at scale. FanDuel, DraftKings, Bet365: they don't need to pick games. They need to balance the money and collect vig. If they have $10 million on one side and $9 million on the other, they're hoping for a push because they collect vig either way.

This is important for the bettor because it explains why the house can be indifferent to outcome. They profit on volatility of money, not accuracy of prediction. The implication is that you cannot grind on vig alone. You need edge: a consistent ability to find bets where the market's probability is wrong relative to the true probability.

What You're Fighting

Every dollar you wager, you're starting from 2.38 percent below break-even. You're not trying to pick winners. You're trying to overcome the vig and then beat the market on top of that. Professional bettors aim for a 55-58 percent win rate on -110 bets as a minimum target. That gives them margin for variance.

Some sportsbooks offer reduced vig on certain bets: -105 instead of -110. The breakeven threshold drops to 51.27 percent. It looks small. Over 10,000 bets, it's the difference between losing and winning.

"Vig is not your enemy. It's the table cost. You pay it and then you play. The question is whether you're sharp enough to overcome it."