Terms of use

Bookbreaker is a free analysis tool: a calculator for prices, not a sportsbook and not advice. It is not affiliated with any sportsbook.

Who it is for

Adults 21 and over, in a state where sports betting is legal. Whether a bet is legal where you are is yours to check; the app cannot know.

What it does, and what it does not

Bookbreaker works out what a set of prices implies and how uncertain that is. It does not place bets, hold money, connect to sportsbook accounts or know whether a book will honour a price. Every figure depends on the prices and assumptions it is given, and it labels the assumptions it makes. A locked figure holds only if both bets are accepted and stand; books can void, limit or refuse bets, and prices move. Nothing here is financial, legal or betting advice.

Not affiliated with any sportsbook

Bookbreaker is independent. It is not affiliated with, endorsed by or paid by any sportsbook, exchange or prediction market. Their names are trademarks of their owners and appear here only to identify them. No link on this site is an affiliate link.

The app’s licence

The app is free to download and use on as many Macs as you control, including to bet with your own bankroll. You may not redistribute it, sell it or run it as a service for other people. It is provided as is, without warranty of any kind, and its author is not liable for any loss that comes from using it. Read the full licence.

About this site

Figures on this site are computed by the engine when the site is built, and every rival price carries the date it was read and a source. If you find an error, tell us and we will correct it.

Contact

Bookbreaker is built by Matthew Kerr in Grand Rapids, Michigan. Email matthew@kerrandcompanyholdings.com.