Who sets the price, and who follows

Sportsbooks fall into two camps. A few take very large bets, welcome winning customers, and run on thin margins and enormous volume. Their prices move first and are most likely to be right. The rest largely watch those numbers and copy them, with a wider margin and a friendlier app.

Why the difference exists

A book that accepts big informed money finds out immediately when its number is wrong, because someone bets it. That feedback keeps the price accurate. A book that limits or bans winners never gets the feedback, so its numbers drift — and drift is exactly where your edge lives.

This app's reference books

Fair value here is anchored on Pinnacle, the Betfair exchange and BetOnline, weighted rather than averaged flat. Pinnacle carries the most weight because it is the closest thing the industry has to a source of truth. Circa is widely regarded as sharp too, and is coming to the app soon.

Exchanges and peer-to-peer books

Betfair, Novig, ProphetX and prediction markets like Polymarket and Kalshi are marketplaces rather than traditional books — users take both sides and the operator takes a commission instead of building a margin into the price. Sharp bettors use them heavily, so heavy money on one side is a genuine signal. Six thousand dollars sitting on a player prop tells you something a recreational book's price does not.