Closing-Line Capture: Define the Reference

A close needs a written definition

“Closing line” is not one universal timestamp. Operators can suspend or update markets at different times, and some prices remain available around the start of an event. Before comparing any entries, define the reference operator or feed, the exact market and period, the odds format, and the timestamp rule you will use.

For example, a log might specify: “the final recorded pre-event price from one named reference source.” That is a repeatable convention. It should not be presented as a perfect estimate of true probability.

Capture the matching market

Match the entry and reference on event, selection, market, period, and line. A pre-event total at one line is not interchangeable with an in-play total or a later line. Store the source's observed timestamp alongside the price so a later review can tell what was actually compared.

If the reference is unavailable or the market mapping is uncertain, mark the row incomplete instead of substituting a similar price. Building a useful bet log describes the other fields worth retaining.

Use CLV as one review signal

Choose a formula and document it. A decimal-price comparison such as (entry price - reference close) / entry price can show how the two recorded prices differ, but it does not guarantee a future result or establish the quality of a single decision. Use enough consistently captured records before drawing conclusions; variance and sample size explains the limitation of small samples.

Review your records in PhotonOdds

Use your bet log to store the reference source and timestamp alongside each entry, then review missing or inconsistent data before interpreting the metric.

18+ only. Betting carries risk. PhotonOdds provides analytical and educational tools, not a promise of profit or a recommendation to place a bet. If gambling is causing harm, see Responsible Gambling.