Betfair Football Trading: Back, Lay, and Matching

Back and lay are different contracts

Betfair's getting-started guide defines backing and laying for its exchange. A lay request is not a second kind of back bet: the layer accepts the other side's stake and risks a liability determined by price.

Matched size creates the position

A submitted request can be fully matched, partly matched, unmatched, cancelled, lapsed, or voided under the market rules. Betfair's exchange general rules explain matching, price-time priority, cross-matching and market administration for that exchange. Record matched size at each price rather than treating the requested size as executed.

Worked lay-liability check

Suppose an illustrative lay request is fully matched for GBP 10 at decimal odds 4.00.

Lay liability = (4.00 - 1) * GBP 10 = GBP 30

The liability is three times the lay stake because the counterparty's possible profit is GBP 30. A display of "GBP 10 lay" must not be recorded as GBP 10 maximum loss.

Read the price ladder with size

The best displayed back or lay price may have insufficient size for the intended request. For a multi-price fill, preserve each matched parcel and calculate the weighted execution price from the actual sizes. The Betfair historical feed specification documents available-price ladders, traded volume, publish time and market status for historical exchange research.

Commission changes the cash result

Betfair's commission documentation describes commission on net winnings in a market for that exchange. Do not subtract a headline commission rate from every individual winning request without applying the current account and market rules. Preserve the gross market result, applicable rate, discount or charge basis, and net account result separately.

In-play execution record

1. Save event, market, selection, qualifying period and rule version.
2. Timestamp the live match state and information source.
3. Record requested side, size, price and persistence setting.
4. Record every matched parcel and unmatched remainder.
5. Mark suspensions and any event correction.
6. Calculate back stake or lay liability across all open positions.
7. Reconcile gross settlement, commission and net account movement.

The Gambling Commission's in-play standard warns that live information may be delayed. Fast submission does not remove information or execution latency.

Next step

Use Exchange Odds Explained for the next part of this topic.

Continue learning

• Next guide: Cash-Out Strategy
• Related guide: How In-Play Sportsbook Markets Are Priced and Suspended

Assumptions and limitations

The worked position is illustrative and excludes partial matching, reduction factors, premium charges and currency conversion. Betfair rules, commission, market availability and account terms can change and do not describe every exchange. Trading language does not imply that repeated back-and-lay activity is profitable.