Live odds
What the market snapshots are, and what Live adds.
The snapshots
The archive holds prices from more than one kind of source, and rather than flatten that away we publish which is which. Every priced match carries kickoff_book_pct: the three prices as probabilities, added up.
That one number tells you what you are looking at. A three-way exchange book runs near 102%, because an exchange takes commission rather than building in a margin, so the implied probability is close to what the crowd actually thought. A single bookmaker runs 105–108%, with the margin in the price. A best of market price, taken as the best available across many bookmakers, can even land slightly under 100%.
Filter on it rather than trusting a label. If your work needs prices with no margin in them, take kickoff_book_pct between 1.00 and 1.03. If you only need a reasonable price, take everything. Anything far below 1.00 is not a real book and is left out of our own aggregates.
Two snapshots are recorded on a match. Kickoff is the market as the game started. Half-time is the same market at the interval: the drift between them is the information.
Implied probability and overround
Implied probability is 1 / price. Summed across all three outcomes you get the book percentage, stored on every priced match as kickoff_book_pct so you never have to recompute it.
/v1/odds/overround gives it by competition and season, and it is a decent
proxy for how seriously a market was taken.
What Live adds
Archive gives you settled history. Live removes the date guard entirely and adds
today’s card, fixtures ahead, in-play scores and events, and current prices, plus webhooks that post
kickoffs, goals, red cards, lineups and results to you, and a /v1/live that answers
304 when nothing has changed.
If you are modelling on history, Archive is the plan. Live is for anything that has to react while a match is happening.
A word of care
These are records of what a market showed at a moment in time. They are historical facts, not predictions, and nothing here is betting advice. Where a figure is derived rather than measured (a backtest, a calibration), the page it appears on says so.