How we collect and measure our data

What this site is

The Odds Lab is an independent information site about trading on betting exchanges. It is not a betting operator, it does not take bets and it is not affiliated with any operator. At the time of writing no link on this site pays us anything; if that changes, it will be said next to the link.

Where the data comes from

We read prices from Betfair's Italian exchange through Betfair's official API, using an Italian account. The Italian exchange has its own pool of money, separate from the international exchange used in the UK. Everything we publish about volumes and prices describes the Italian exchange. We do not measure the international one, and we do not estimate its numbers.

The collection only reads. It never places, changes or cancels an order.

How the articles are written

Articles are drafted with AI tools and checked against our own data before publication: every figure is recalculated from the archive, and a compliance check blocks any page that links to an operator or invites the reader to bet.

What we record

• Four snapshots a day, at 06:00, 12:00, 18:00 and 21:30 UTC.
• Three kinds of market: football match odds, tennis match odds and football outright winner markets. At each snapshot we take the 100 most traded markets of each kind at that moment. Markets that never reach the top 100 are not in the archive, so our liquidity figures describe the busiest markets, not all of them.
• For every selection: the last traded price, the three best prices on each side of the book with the money available at each, and the total volume matched on the market so far, in euros.
• After a market is settled, the winning selection, read from Betfair's settled market.

Up to 19 October 2026 the archive held 11,073 football and tennis match odds markets, collected over 62 days from 31 July 2026. The days are not consecutive: collection stopped between 7 and 25 September 2026, and that gap is permanent.

How we measure

• Pre-match only. We keep snapshots taken before the scheduled start and not flagged as in-play.
• Liquidity is the total volume matched on a market at our last snapshot before the start. That snapshot falls, at the median, 3 hours before the start: money matched in the final hours and in-play is not counted.
• Price movement compares the first and the last traded price of a selection before the start. We use traded prices, not offers on the book, because an offer can be placed and withdrawn by anyone at no cost.
• Outcomes against prices. We compare how often selections actually won with the probability implied by their final price, normalised for the overround.
• Volume filters first. Analyses of price behaviour use only markets above a stated volume (3,000 EUR in our first analysis), because a price in a market with a few euros matched says almost nothing.
• Commission is not included in our analyses unless a page says otherwise.

What the data cannot tell you

• Anything about the international exchange, where most UK traders operate.
• Anything in-play: our snapshots stop at the start.
• Anything about horse racing, other sports or other market types.
• Market depth at a given instant: cumulative volume is not the money resting on the book at any one moment.
• Whether a pattern will last. Our first analysis covered one month of data, and every page that uses it calls it a hint or a hypothesis, not a proof.

Monthly figures

Once a month we publish the liquidity figures, league by league and by tennis tournament level, in our liquidity report (in Italian, the language of the exchange's own users).

Corrections

When we find an error, we correct the page and show the date of the update next to the date of publication. On 20 October 2026, for example, several pages presented our volume figures as if they described the exchange in general; they now say that they come from the Italian exchange, and their conclusions are limited to it.

To report an error: [email protected].

This site is for information only and does not give betting advice. Gambling is for adults (18+) and can be addictive.