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Book Margin

Hold & Vig Calculator

See how much a book keeps on a market. Enter the two prices to get the hold percentage, the overround (vig/juice) and the fair no-vig probabilities.

Hold %
Overround (vig)
Fair prob A
Fair prob B

Hold vs. vig vs. overround

These terms all describe the book's cut, but they aren't identical:

Why it matters

Hold is the headwind you bet into. A market with 2% hold is beatable with a small edge; a 7% hold prop needs a big edge just to break even. Comparing hold across books tells you where the market is tightest — and where a soft price is most likely to be genuinely +EV.

Standard two-way markets run 4–5% hold; player props are often 6–10%. PropPrizm scores every book's hold and pricing to find where one book steps out of line — see how it works.

Stop doing this by hand

These calculators do one bet at a time. PropPrizm's EV+ board runs the de-vig and EV math across every book, on every prop, live — and surfaces only the ones where a book is soft versus the market consensus.

See the EV+ board →

Frequently asked questions

What is a normal hold percentage?

Major two-way markets (spreads, totals) typically hold 4–5%. Player props and less liquid markets often hold 6–10%. The lower the hold, the smaller the edge you need to profit.

What is the difference between hold and vig?

Vig (overround) is how much the two sides’ implied probabilities exceed 100%. Hold is the fraction of total wagered money the book keeps: hold = (total − 1) / total. Hold is always a bit smaller than the overround.

How do I lower the hold I pay?

Line-shop: take the best available price on each side across books. Betting the sharpest, lowest-hold market and avoiding high-juice props keeps more expected value in your pocket.