From the evaluator behind 100,000+ pairs and the creator of the Shoemetrics grading system.
Condition Areas
Shoemetrics evaluates every sneaker across four physical components. Each is scored independently, then combined into a single 1–10 overall grade. The system works across all brands — Nike, Jordan, Adidas, New Balance, and beyond.
You also need specific lighting to see many flaws. Under normal room lighting, a shoe can look clean. Under direct, angled light, glue stains and discoloration become obvious. Every Shoemetrics evaluation uses controlled lighting for this reason.
The upper is everything above the midsole — toe box, medial, lateral, heel, tongue, laces, and eyelets. It's the largest scoring area and usually the first thing buyers notice.
Glue stains. Without question. 99% of shoes have visible glue staining on the upper. It's the single most common flaw across 100,000+ pairs — and most people don't even notice it until you put the shoe under direct light.
The midsole sits between the upper and outsole. On Jordans, this is typically the visible foam or Air unit. Aging hits midsoles hard.
Glue stains between midsole components are just as common as on the upper. The midsole is where multiple layers meet, and adhesive overflow is visible on almost every pair I evaluate.
The interior covers the insole, lining, size tag, and internal heel. Often overlooked, but it tells the real story of how much a shoe has been worn.
The interior is the area people forget to check — and the area that's hardest to fake. Lint and pilling tell the real story of how a shoe was stored and worn.
The outsole is the bottom of the shoe — tread pattern, rubber, and any exposed Air units. Wear here directly correlates with how much the shoe has been walked in.
The outsole is the most honest part of the shoe. The factory sheen disappears after a single wear, dirt embeds in the tread pattern, and worn tread doesn't lie. You can argue about creases — you can't argue about missing tread.
The Shoemetrics Grading Scale
Every Shoemetrics grade falls on a 1–10 scale with half grades. The overall score is a weighted composite of all four component scores — not a simple average.
Reading Nike Tags
The size tag is a sneaker's birth certificate. We'll use Nike as the primary example — it's the most searched and most collected — but these principles apply across brands.
Adidas, New Balance, and other brands use different tag formats — guide coming soon.
Hover or tap each field above to see what it represents. The style code + colorway suffix is the sneaker's unique DNA — it's how every pair is cataloged, searched, and verified.
Roughly 80% of the tags I evaluate come from China and Vietnam, with slightly more from Vietnam. The shift tells a story about tariffs and how they've reshaped the sneaker supply chain.
Older tag format with different font styles. Production codes, factory identifiers, and layout all differ from modern tags. These are the tags where experience matters most — the inconsistency across this era means you need to know what "right" looks like for a specific model and year.
Updated font structure with UPC barcode present. Six-digit style codes became universal. This is the era where Nike's tag system stabilized into a predictable, verifiable format — making authentication through tag comparison significantly more reliable.
Major structural change starting around 2019: QR code added, UPC removed. Font styles continue to evolve every few years. The QR code links to Nike's product database and adds another layer of verification — though counterfeiters have started replicating these as well.
Try It — Enter a Nike Style Code:
Style Codes & Colorway Suffixes
Nike's style code system follows a consistent format: a base number identifies the silhouette, and a hyphenated suffix identifies the colorway. The suffix is often the fastest way to narrow down which version of a shoe you're looking at.
These are Nike/Jordan conventions. Adidas, New Balance, and other brands use different numbering systems — guide coming soon.
Nike's colorway suffix system is a general guideline — it doesn't work for everything, especially given that some silhouettes have several hundred colorways. But it was an early internal system for categorizing colors and it still holds for the most common codes.
| Suffix | Typical Meaning |
|---|---|
-001 | Black / Dark primary |
-002 | Black / alternate secondary |
-010 | Grey primary |
-100 | White primary |
-101 | White / Red secondary |
-300 | Green primary |
-400 | Blue primary |
-600 | Red / Varsity Red primary |
-700 | Gold / Yellow primary |
-991 | Nike By You (custom/NIKEiD) — essentially the only suffix used for Nike By You orders |
Sample Codes & Special Tags
Samples are pre-production pairs made for internal use — sales meetings, wear testing, photo shoots, or player approval. They're among the rarest sneakers in existence and carry distinct markings.
The most valuable samples are unreleased pairs — shoes that never made it to retail. The least valuable are typically 999 samples (production test runs). Everything else depends on the specific shoe, silhouette, and story behind it.
| Factory Code | Country | Classification |
|---|---|---|
VH | Vietnam | Final Adoption GGP |
VF / VW | Vietnam | Final Adoption GGP |
FT | Taiwan | Adoption Sample GGP |
JJ | Indonesia | Sample GGP |
IA | Indonesia | Sample GGP |
QM | Indonesia | EHQ Sample / Global Geo Pilot |
YS | Taiwan | Final Adoption GGP |
XC | China | Sample GGP |
DS | Korea | Sample GGP / GGP Sample |
IR | Indonesia | Final Adoption GGP / EMEA Samples |
SZ | China | GGP / GGP Sample |
CV | Vietnam | GGP Sample |
PC | Taiwan | GGP Sample |
FT / LU | Taiwan / China | Final Adoption GGP |
VT | Vietnam | GGP Sample |
VF | Vietnam | Final Adoption GGP |
| Factory Code | Country | Classification |
|---|---|---|
VY | Vietnam | Sample Pro |
VT | Vietnam | Promo Sample / Pro Sample |
XE | China | Promo Sample |
SZ | China | Pro Sample |
XC | China | Pro Sample |
FT | Taiwan | Pro Sample |
PC | Taiwan / Vietnam | Pro Sample / Look See Sample |
LN2 | China | Promo Sample |
LN3 | China | EST Sample / Promo Sample |
LN4 | China | Promo Sample / Player Exclusive |
VF | Vietnam | PE Sample |
| Factory Code | Country | Classification |
|---|---|---|
VY | Vietnam | Friends & Family Edition |
XB | China | F&F Sample |
FTSS | Taiwan | Salesman Sample |
T2 | Korea | Unreleased Sample |
VO | Vietnam | Customized AF1, Nike ID |
BR | Brazil | Rare Vintage |
IW | Indonesia | Vintage Rare |
| (none) | Various | Often vintage, unreleased, or special production runs — no factory code appears frequently across Indonesia, Vietnam, Taiwan, Thailand, China, and Korea |
Sample code data compiled with thanks to @donniebsoles, who originally published this research on Instagram. Used with permission.
Production Eras
How a sneaker was made — and when — directly affects what condition issues to expect. Materials, adhesives, and construction methods have changed dramatically over four decades.
Most basketball shoes are leather or nubuck with polyurethane soles. Runners use more mesh with EVA and polyurethane. Polyurethane doesn't age well — most shoes from this era, except OG Jordan 1s (which have rubber soles), have fallen apart, are unwearable, or are actively crumbling. Rubber and vulcanized soles are the survivors. Unless it's a rubber-soled shoe, expect structural issues. These are display pieces, not wearable sneakers.
Similar sole compounds to the OG era for the most collectible shoes. The most collectible pairs — Jordans, Air Maxes — have likely crumbled or are in pieces due to their sole compositions. Dunks, because of their rubber soles, are still going strong. Shape and sizing is off on aged pairs, glue is likely yellowed or separating. Dunks from this era can still be great. Jordans and Air Maxes are gambles — inspect the soles carefully.
More Phylon (compression-molded EVA) which lasts significantly longer than polyurethane. A lot of these shoes are still presentable — probably not the most comfortable for daily wear, but they've largely held up structurally. Expect yellow glue stains and likely some glue separation. Wearable but showing age. Good value for collectors who want shoes they can actually put on.
The invention of performance foams — Boost (Adidas), React (Nike), and others. These yellow but hold up well structurally over time. Most shoes from this era are in solid shape. Foam yellowing is the main cosmetic issue. The safest era to buy pre-owned — materials are more durable and age more gracefully.
How Sneakers Age
Even unworn sneakers degrade over time. Understanding aging is essential for grading vintage and deadstock pairs accurately.
Most yellowing happens with shoes that aren't worn. Glues solidify and clear panels — like visible Air units — start to deteriorate. The biggest enemy of sneakers is actually never wearing them. Glue typically turns yellow after several years of sitting. Storage in direct sunlight accelerates yellowing dramatically.
Jordan 1s are great — rubber soles that last. Jordans 2 through 9 all have crumbling issues due to polyurethane. Almost all vintage Air Maxes have similar problems. Dunks last. When crumbling starts depends entirely on storage environment and whether the shoes were ever worn.
Anything too dry will cause glue separation over time. The fix is — seriously — wearing them a couple of times a year. Using the shoe gives the glue its tensile strength. Shoes that sit in a box for a decade without being worn will separate.
Rubber holds up best over decades. Polyurethane is the worst — it literally disintegrates. Leather ages well if stored properly. Mesh and synthetics hold up but can yellow and become brittle.
Common Misconceptions
"Deadstock means perfect."
MythDeadstock means never worn — that's it. Plenty of unworn shoes are far from perfect. Yellowed glue stains, oxidation, crumbling, poor storage — a deadstock shoe that sat in a garage for 15 years can grade lower than a pair that was worn carefully a dozen times.
"Worn once means near-new."
MythMost "worn once" pairs weren't actually worn once, or they were worn once in conditions that weren't kind to the shoe. One wear through rain or on rough pavement can do more damage than twenty wears on clean indoor surfaces.
"Yellowing means the shoe is fake."
MythNo. Yellowing is chemistry — oxidation of materials and adhesives over time. Every shoe yellows eventually. It's a sign of age, not a sign of counterfeiting.
"Creases mean the shoe is beat."
MythA hallmark of quality leather is how soft it is. Natural creasing on premium leather can actually make a shoe look better — it develops character. But lower quality leather — the hard stuff I call "plastic leather" — makes creasing look terrible. The material determines whether creases are a flaw or a feature.
"If a shoe looks too perfect, it must be real."
MythBecause fakes are sometimes made under less rigorous conditions with tighter quality control for smaller batches, some counterfeits actually grade higher than their authentic counterparts. A perfect example: the Jordan IV "Travis Scott" and the Jordan 13 "Melo" — both notorious for blatant glue staining where the midsole meets the light-colored nubuck or suede upper. The stains really stand out. Almost any time I see a pair of either shoe without glue stains, I operate from the assumption that it's fake. Perfection can be a red flag.
Spotting Fakes
After evaluating 100,000+ pairs, pattern recognition becomes instinct. But here are the universal red flags that apply regardless of model.
Look at StockX's top 25 sellers on any given day — the top 5 most faked models will be somewhere on that list. Counterfeiters follow the money. Whatever is selling for the highest premium is what's being replicated.
Size tag. 100%. The tag is the first thing I check on every single pair. Typography, kerning, layout, print quality — the tag tells you more than almost any other part of the shoe.
Weight and the feel of the material. You can study stitching and tags all day in photos, but you can't feel the difference between real and fake leather, or notice that a shoe is 20 grams lighter than it should be. That's why in-hand evaluation exists.
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