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We do not publish a proprietary "fair value," momentum, or volatility score.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.

How we use AI

We use AI tools to help research, draft, and maintain parts of this site. A person reviews what gets published and we fix errors when we find them, but AI-assisted content can still be wrong or out of date, so confirm the details that matter on the marketplace's own listing before you buy. We do not publish AI-generated reviews or testimonials. No AI system reads or processes anything you submit to us.

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