Odds API Guide · 7 September 2026

What Are Consensus Odds and How SockOdds Calculates Them

bookOdds is the consensus with the vig in; fairOdds is the exchange-and-sharp-book price with the vig out. How each is derived and what fairOddsAvailable tells you.

Consensus odds are one of the most useful indicators in betting data, and one of the most misused. SockOdds returns two of them on every market, and they mean different things.

bookOdds — the consensus with the vig in

bookOdds is the consensus American price across the bookmakers pricing that side, computed from each book's main line. It is what the market is offering, margin included. bookOddsAvailable is true when at least one book has the side open.

fairOdds — the price with the vig out

fairOdds is derived from the exchange and sharp-book prices (the Betfair Exchange, Pinnacle, ProphetX, Kalshi and Polymarket where they price the market) with the margin removed so the implied probabilities of the sides sum to one. Where those sources do not price the market, fairOdds is null and fairOddsAvailable is false — it is never estimated from soft-book prices alone. On the Lite plan fairOdds is always null.

Lines

For spreads and totals the consensus and fair values come with their line: bookSpread / bookOverUnder and fairSpread / fairOverUnder. Both sides mirror each other (home +3 ↔ away −3).

Using them

• Edge: fair implied probability minus a book's implied probability (1 / decimal).
• Sanity: a price that beats bookOdds by a lot on a market with fairOddsAvailable: false is a soft-book outlier, not necessarily value.
• Never act on a price with available: false or on an event with info.stale: true.

Full detail in the consensus odds reference.

Read more: Common Odds API Questions, Answered for Australia