Resources
Sep 26, 2026
How Gradeon turns two phone photos into a pre-grade: four sub-grades per side, fixed weights, a cap rule that stops strong areas hiding a weak one, and 11 defect types rated 1–5.
By the Gradeon Team · Updated
Gradeon pre-grades a card by scoring centering, corners, edges and surface on the front and back, weighting them 15/25/25/35%, capping each side at its weakest area plus 1.0, then combining both sides into one grade.
This guide explains every step of that process, using the same rules the app runs today. If you only want the definitions, the Gradeon glossary has every term on one page.
A pre-grade is an AI estimate of the grade a professional grading company, such as PSA, BGS or CGC, would most likely give your card. It is not an official grade and it never replaces one. It is a decision aid: it tells you whether a card is worth submitting, and what to expect before you pay.
Three things make a Gradeon pre-grade different from a guess:
It uses the 1–10 scale in 0.5 steps, the scale collectors already read on slabs.
The front and the back are graded separately, then combined.
Every grade below 9 is tied to at least one specific defect, and every defect is drawn on your photo, so you can see exactly why a card lost points.
Each grade maps to a label and a colour band in the app.
Grade | Label | Band |
|---|---|---|
9.5–10 | Gem Mint | Pristine (green) |
9 | Mint | Pristine (green) |
8–8.5 | NM-MT (Near Mint–Mint) | Good (lime) |
7–7.5 | NM (Near Mint) | Good (lime) |
6–6.5 | EX-MT (Excellent–Mint) | Fair (orange) |
5–5.5 | EX (Excellent) | Fair (orange) |
4–4.5 | VG-EX (Very Good–Excellent) | Poor (red) |
3–3.5 | VG (Very Good) | Poor (red) |
2–2.5 | Good | Poor (red) |
1–1.5 | Poor | Poor (red) |
The full definition of each label is in the grading scale section of the glossary.
Each side of the card gets four sub-grades, each on the same 1–10 half-point scale:
Area | Weight | What it measures |
|---|---|---|
Surface | 35% | Scratches, print lines, dents, creases, stains, scuffing, loss of gloss |
Corners | 25% | Sharpness of the four tips: whitening, softness, rounding, fraying, bends |
Edges | 25% | The four borders: whitening, chipping, nicks, fraying, silvering on foil cards |
Centering | 15% | How evenly the printed image sits inside the card |
Surface carries the most weight because it is where the most value-destroying defects live, such as a crease or a deep scratch through the artwork, and it is what a good photo shows best.
The calculation has two steps, and both are deterministic: the same sub-grades always produce the same result.
Step 1: one grade per side. Gradeon takes the weighted average of the four sub-grades, caps it at the lowest sub-grade plus 1.0, and rounds to the nearest 0.5.
Step 2: one grade for the card. Gradeon averages the front and back grades, caps the result at the weaker side plus 1.0, and rounds to the nearest 0.5. That number is the combined grade you see on the result screen.
The cap rule is what makes the grade behave like a professional one. Three perfect areas cannot hide one bad corner, and a flawless front cannot carry a damaged back by more than one point.
A clean modern card. Front: centering 9, corners 8.5, edges 9, surface 8. The weighted score is 8.525, under the cap of 9, so the front is 8.5. Back: 10, 9, 9, 9 gives 9.15, so the back is 9. The average is 8.75, which rounds to 9 · Mint.
A card with a crease. Front: centering 8, corners 7, edges 7, surface 6 (a crease caps surface at 6). The weighted score is 6.8, rounded to 7. Back: 9, 8, 8, 8 gives 8.15, rounded to 8. The average is 7.5, so the card is 7.5 · NM.
The cap rule at work. Back: centering 7 (a 62/38 cut), corners 9, edges 9, surface 9. The weighted score is 8.7, but the cap is 7 + 1 = 8, so the back is 8. Without the cap, an off-centre back would score near NM-MT+ on three perfect areas alone.
Gradeon finds the physical edge of the card and the printed border, measures the four border widths and turns them into two ratios: left/right and top/bottom, written like 52/48 | 49/51. A perfect card is 50/50 | 50/50. The deviation is the worse of the two axes.
Deviation | Example ratio | Centering sub-grade |
|---|---|---|
≤ 2% | 50/50 – 52/48 | 10 |
≤ 5% | 53/47 – 55/45 | 9 |
≤ 8% | 56/44 – 58/42 | 8 |
≤ 12% | 59/41 – 62/38 | 7 |
≤ 16% | 63/37 – 66/34 | 6 |
≤ 20% | 67/33 – 70/30 | 5 |
Beyond 20%, the sub-grade drops one point for every further 5%. The same scale applies to the front and the back.
Centering is also the one area you can check with your own eyes, so after every Full Grade the app asks you to confirm it. The eight pins are already placed: if they line up, one tap confirms; if not, you drag them and the grade updates live. The grade is not final until both sides are confirmed.
Every photo is inspected by a vision model with grading instructions written around PSA and BGS standards. For each defect it returns a type, a severity, a confidence score and a box drawn on your photo.
There are 11 defect types, each with a 3-letter code: scratch (SCR), whitening (WHT), dent (DNT), crease (CRS), edge wear (EDG), surface damage (SRF), dirt (DRT), print line (PRL), soft corner (COR), chip (CHP) and other (OTH). The article The 11 Defects Every Grader Looks For explains how to spot each one.
Each defect is rated on a severity scale from 1 (minimal, only visible zoomed in) to 5 (extreme, it dominates the card). When the model hesitates between two levels, it takes the lower one.
Three rules keep the list honest:
Only defects with a confidence of 0.7 or more are reported, and whitening needs 0.8, because it is the easiest thing to confuse with glare.
A photo reports at most 10 defects, the most significant ones.
An empty list is a valid answer. A clean card gets no invented defects.
Glare, factory cut lines, holo patterns and print texture are never counted as defects.
After the model reads each area, hard caps based on the defect list make sure a sub-grade is never higher than the defects allow. Caps only ever lower a grade.
Rule | Maximum sub-grade |
|---|---|
No defect in the area | 9.5 |
1 defect | 9 |
2 defects | 8 |
3 defects | 7 |
4 or more defects | 6 |
Any defect of severity 3+ | 7 |
Any defect of severity 4+ | 5 |
Any crease (surface) | 6 |
2+ creases, or a crease beyond the border (surface) | 4 |
In plain words: one visible defect costs you Gem Mint, two cost you Mint, and a creased card tops out around 7 overall.
Corners, edges and surface top out at 9.5, because a 10 in those areas would need confirmation under magnification that a phone photo cannot give. Only centering can score a full 10. As a result, 9.5 Gem Mint is the highest overall grade the app awards today. A Gradeon 9.5 is the card you submit hoping for a PSA 10.
Standard analysis inspects each photo once, in full, and is ready in about 1–2 minutes. Deep Analysis, available on Gradeon Pro, also crops every corner and zooms into suspicious surface areas at full resolution before answering, like a grader with a loupe. It takes 5–10 minutes, and the app notifies you when it is ready.
Both modes use the same rubric. Detail shots, close-ups of a corner, edge or patch of surface, only add evidence. They are worth adding even on a card that looks clean.
A pre-grade is only as good as the photos behind it. Use a dark, matte background, soft diffused light with no glare, and keep the card flat and parallel to the camera, filling 70–80% of the frame. The full checklist is in How to Take the Perfect Picture for Accurate Pre-Grading.
Scan the front and back with Gradeon and get four sub-grades per side, every defect marked on your photo and a pre-grade on the PSA-comparable scale. Gradeon pre-grades Pokémon, One Piece and Riftbound cards, and every account gets 3 free Full Grades each week.
Gradeon scores centering, corners, edges and surface on the front and back of the card, weights them 15/25/25/35%, caps each side at its weakest area plus 1.0 and combines both sides into one pre-grade on the 1–10 scale.
Not a plain one. Each side is a weighted average of its four sub-grades, capped at the lowest sub-grade plus 1.0. The card's grade is the average of both sides, capped at the weaker side plus 1.0, rounded to the nearest 0.5.
Not today. Corners, edges and surface top out at 9.5 because a 10 would need magnification a phone photo cannot give, so 9.5 Gem Mint is the highest overall grade the app awards.
No. It is an AI estimate of the grade PSA, BGS or CGC would most likely give your card. It is not a certification and never replaces an official grade.