Coming soon
We publish accuracy stats once we have at least 10 verified outcomes. Currently: 0 verified.
How we measure
Every Gemmr user can report what grade their card actually came back as. When that report includes a cert number, we cross-verify it against the grading service's public lookup. Only verified outcomes count toward the stats on this page — we don't take anyone's word for it, including our own.
A prediction is “accurate” when it lands within ±0.5 grade of the verified result. That's the tolerance grading services themselves treat as functionally identical. Stricter measures (exact match) and looser ones (within ±1) are visible in the breakdown below.
Data refreshes hourly. Predictions are made before the user reports the outcome — no hindsight cheating. Suppressed when sample size is below 5.
By grading service
By category
Recent verified outcomes
No verified outcomes yet.
Where we missed
We publish our worst calls from the last 90 days. If you only show your wins, you're not building trust — you're building a sales pitch.
No verified outcomes yet.