Methodology

SluggerData is evidence-first. Every value is built from real sold listings and labeled with how much we can trust it. These pages document exactly how.

Sold-comps methodology

Source, matching rules, exclusions, median calculation, outlier handling, confidence levels, shipping treatment, refresh cadence, and how to report a bad comp.

Read the methodology

On "fair value" and momentum scores

We do not publish a proprietary "fair value," momentum, or volatility score. A transparent read, how many sales, of which grade, how recent, and how consistent, is more useful and more honest than a single number with no reproducible formula. If we ever introduce a scored metric, it will ship with a published, validated methodology first.

Questions about a specific value? Every card links its source sales and a "report a comp" option on the corrections section.