Vig

Vig (short for vigorish) is the sportsbook’s commission — built directly into the odds. It’s why both sides of a coin-flip game are priced at -110 instead of even money. The vig is the gap between the implied probabilities and a true 100%.

How vig is built into the line

Take a basketball game with a true 50/50 outcome. A fair line would be +100 on both sides (decimal 2.00, implied 50%). A real sportsbook posts -110 on both sides instead.

Implied probability of -110: 110 / 210 = 52.4%.

Both sides at 52.4% sums to 104.8% — that 4.8% over 100% is the overround. The book wins it on the average bet over time, regardless of who wins individual games.

Why it’s called “juice”

If you bet -110, you risk $11 to win $10. The extra $1 you risk on top of even money is the juice. Same concept, different phrasing.

How to “remove” the vig

To estimate the book’s true probability (not the inflated implied probability), divide each side’s implied probability by the total. For two sides each priced at -110:

• Each implied: 52.4%
• Total: 104.8%
• Vig-free: 52.4% / 104.8% = 50.0%

For asymmetric games, the vig-free probability gives you a better picture of the book’s actual lean. Tools called vig removers automate this.

Why it matters

Most retail bettors lose long-term not because they pick poorly, but because the vig grinds them down. Beating a -110 line consistently requires a win rate above 52.4%, not 50%. That 2.4% gap is what you have to overcome before you’re even break-even.