CobiaHow the hold calculator works
The hold (also called juice or vig) is the sportsbook's margin — the share of every dollar wagered it expects to keep if it balances the action on both sides. You can read it straight off the two prices: convert each side to an implied probability, add them, and the amount above 100% is the source of the house's edge.
Worked example
The classic -110 / -110 line: each side implies 110/210 ≈ 52.4%, so the book totals 104.8%. Hold = 1 − (1 ÷ 1.048) ≈ 4.5%. That's the standard "vig" you pay on a coin-flip market — you risk $110 to win $100 on a truly 50/50 event.
What "hold" really means for you
Hold is the house's guaranteed margin, and it comes straight out of your expected return. Every extra point of hold is a point of edge working against you before the game even starts. A market that holds 6% instead of 3% quietly doubles the tax on your action — over hundreds of bets that gap is the difference between a losing and a break-even bettor.
Typical sportsbook hold vs an exchange
Standard two-way sportsbook markets hold roughly 4–6%; parlays and exotic props hold far more. An exchange like Polymarket charges only a tiny exchange fee, so its effective hold is a fraction of a book's. Lower hold means the prices are closer to true probability — and every cent you don't hand to the house stays as expected value in your pocket.