Methodology
SlabGrader uses structured AI analysis to evaluate trading cards across the same dimensions professional graders assess. Here's how the system works.
1
Upload
Take clear photos of your card's front and back
2
AI Analysis
The system evaluates centering, corners, edges, and surface quality
3
Metric Breakdown
Get detailed sub-grades for each category with confidence ranges
4
Verdict
Receive a projected grade, market valuation, and submit/hold recommendation
Grading Metrics
Four Dimensions of Card Quality
Every card is evaluated across four sub-grades — the same categories PSA uses. Each dimension receives an independent score, and the final projected grade is determined by the lowest sub-grade. This mirrors PSA's weakest-link methodology.
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Centering
Measures border width symmetry on front and back. Combines algorithmic pixel-level measurement with AI visual assessment for accuracy on both bordered and borderless designs.
PSA 10: 55/45 front, 75/25 back
PSA 9: 60/40 front, 90/10 back
PSA 8: 65/35 front, 90/10 back
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Corners
Evaluates all four corners individually on both sides. Checks for whitening, dings, chips, fraying, and softness. Grades to the worst corner found.
Sharp point = no deduction
Slight softness = PSA 8-9 range
Visible wear = PSA 7 or below
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Edges
Scans the full perimeter for chipping, whitening, nicks, silvering, and roughness. Distinguishes real defects from photo artifacts and holder reflections.
Clean edges = PSA 9-10
Minor whitening = PSA 8
Visible chip = PSA 6 max
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Surface
Examines front and back for scratches, print lines, dimples, gloss loss, staining, and creases. Accounts for chrome/prizm/refractor finish characteristics.
Clean surface = PSA 9-10
Light print line = PSA 8
Any crease = PSA 6 max
Accuracy
Self-Calibrating System
When you log actual PSA results back into your collection, SlabGrader tracks its prediction accuracy over time. The system uses this calibration data to adjust future assessments — if it has historically overgraded edges, it applies stricter edge evaluation on your next scan. This feedback loop improves accuracy with every graded card you log.
Holder Detection
Cards in Holders
SlabGrader adjusts its confidence when cards are photographed inside protective holders. Top loaders partially obscure edges. Magnetic cases and One-Touch holders hide edges and corners behind thick acrylic. The system identifies holder artifacts — ridge shadows, case reflections, surface glare — and avoids penalizing the card for them, while widening the confidence range to account for what it can't see.
Market Intelligence
Real-Time Valuation
After grading, SlabGrader pulls recent sale data to estimate raw and graded values at PSA 6 through 10. It factors in PSA population counts, recent comparable sales, and market trend direction to deliver a submit-or-hold verdict with estimated profit and ROI. The goal is a clear, actionable recommendation — not just a number.