What GemDelta Does
GemDelta finds Pokemon cards where buying raw, grading, and reselling has positive expected value. It compares the current buy price with measured grading outcomes, PSA 10 resale references, and the costs of grading and selling so the board can surface cards worth studying.
Reading The Dashboard
- Price
- What it costs to buy right now, including shipping where we have it.
- Best case
- What you'd make if the card came back a PSA 10. It is the ceiling, not the expectation.
- Expected profit
- What this card is worth buying on average, after grading and selling costs, weighing the chance it grades a 10 against the chance it doesn't.
- Gem rate
- How often this exact card has actually come back a PSA 10, from real population data. Blank means we don't have enough data and we won't guess.
What "not scoreable" means
A card only gets expected-profit numbers when both inputs are present: a measured PSA population report for the gem rate and a PSA 10 price reference. If one is missing, GemDelta leaves the profit math blank and says which piece is missing. That blank is deliberate: a blank is better than a guess that looks precise.
How The Numbers Are Worked Out
Think of each raw buy as a set of possible endings. Some copies come back PSA 10 and sell near the best-case price. Some do not, and are worth less after the grading and selling costs. Expected profit blends those endings by how often the card actually gems, then subtracts what you paid and the costs tied to grading and selling.
Round-number example
Say a raw card costs $20, grading and selling costs add $25, and the measured gem rate is 25%. If the PSA 10 outcome would net $75 after those costs, but the non-10 outcome would lose $20, the average over many tries is about $4 profit per card. One actual card can still lose money; the number is an average over many attempts, not a promise about this copy.
Where The Data Comes From And How Fresh It Is
- PriceCharting provides price-guide values and sold-comps data used for raw and graded price references.
- TCGplayer provides current raw buy prices, Near Mint supply, seller depth, and sealed-product supply.
- GemRate and PSA population data provide the measured gem rate and population counts.
- eBay feeds live listing checks for sealed cases and regrade/crack-repair opportunities.
PSA 10 best-case pricing uses dated sold comps inside a 45-day effective window when they exist. If no PSA 10 comp is inside that window, scoring may use PriceCharting's published PSA 10 market value for the grade. In this codebase that fallback is a sales-backed market value, not an estimate warning; the difference is recency.
Population data follows a flat 30-day floor per card, so the practical rhythm is about monthly. A scheduled run should not spend GemRate or PSA work on the same card more frequently unless a human explicitly forces it.
The Boards
Crack & Repair is for graded slabs that may be worth cracking, repairing, or regrading when the spread between the current slab and a stronger outcome is large enough to inspect.
Sealed tracks sealed cases from eBay and also has a TCGplayer sealed-product supply view in the codebase. It is a free global board; Supply Watch stays upgraded because it scans per-user lists.
Watchlist And Collection
Your watchlist is the private list of cards you want to track. Your collection is your private owned-card inventory. Anonymous visitors can browse public boards, but watchlist and collection data are scoped to your signed-in account.
Plans
Free
Dashboard, Cards, Card detail, Sets, Recommendations, Crack & Repair, Sealed
Signed-in
Watchlist, Collection
Upgrade
Supply Watch
This section is generated from the RBAC feature table. Admin tools are operational controls, not a public plan.
Glossary
- raw
- An ungraded card, usually bought as a single.
- slab
- A graded card sealed in a grader's plastic holder.
- gem rate
- The measured share of graded copies that came back a PSA 10.
- pop
- Population: how many copies a grading company has recorded at each grade.
- PSA
- Professional Sports Authenticator, one of the graders used for population and price references.
- CGC
- Certified Guaranty Company, another grading company used on regrade and price checks.
- TAG
- Technical Authentication & Grading, used by the crack/repair flow when a listing exposes a TAG report.
- reverse holo
- A printing where the card body is foil instead of the artwork window.
- 1st edition
- An older print marker that can change identity, price, and population data.
- NM
- Near Mint, the TCGplayer condition GemDelta uses for raw buy and supply checks.
- PSA 10
- The gem-mint grade used as the best-case resale outcome on the dashboard.
- PSA 9
- A lower graded exit used by the model as the realistic non-10 outcome.
- EV
- Expected value: the average result over many similar attempts. The dashboard spells this out as expected profit.
- ROI
- Return on investment: expected profit compared with the money tied up in the attempt.
Important
GemDelta gives estimates from historical data. Grading outcomes are uncertain, prices move, supply changes, and one card can do the opposite of the average. Nothing here is financial advice.