Glossary
Overround
Definition of sportsbook overround and book percentage.
Quick answer
Overround is the amount by which the sum of offered-price implied probabilities for a complete mutually exclusive market exceeds 100%.
Example
If two outcomes each imply 52.36%, the book percentage is 104.72% and the overround is 4.72 percentage points.
Why it matters
It provides a compact measure of the displayed pricing margin across the market.
Limitation
It is not identical to the sportsbook’s realized profit or hold over a sample of wagers.
Related reading
Responsible gambling: Gambling involves financial risk. Never chase losses or gamble with money needed for essentials. Eligibility and legal age vary by jurisdiction.