Centering Lab

USE ONLY for questions about published THRESHOLDS, tolerance, rules or SOURCES without grading the user's supplied numeric ratios. For PSA 10 compatibility with supplied ratios use grade_centering instead; it applies rounding and house-specific rules. If face/axis is unknown, ask first without any call. Example: {"house":"BGS","face":"back"}; fields optional, {} returns all. Houses PSA/BGS/CGC/SGC (case accepted), TAG excluded: explain proprietary assessment; never substitute another house. Face front/back in English; case/spaces accepted, reverse/obverse and translations rejected. SGC back has empty bands, no published table or ceiling; never invent one. Returns official/interpreted/approximate status, sources and verification. Not a final-grade prediction.

USE THIS TOOL whenever the user supplies numeric centering ratios and asks whether a card meets PSA/BGS/CGC/SGC or asks for a centering ceiling. Do not calculate by looking up standards yourself. Example: {"front_lr":"55/45","front_tb":"60/40","house":"PSA"}. At least one known face AND axis; if either is unknown, ask first, never assume front/LR. Optional house PSA/BGS/CGC/SGC, TAG excluded. Flat front_lr/front_tb/back_lr/back_tb, or nested {"front":{"lr":"55/45","tb":"60/40"}}; no duplicates. Key/house case accepted. Ratios: percentages, fractions, pairs with / - – — : x or spaces, optional %, or [55,45]/["55","45"]. Scalar 1 rejected; use 1/99. Axis suffix must match field. Changes disclosed in normalizations. Partial input gives incomplete=true: report provisional ceiling and missing data. A ceiling from centering alone is NOT a predicted grade. SGC back alone has no published ceiling.

Measure one ACTUAL photograph. Example shape: {"face":"front","image_base64":"<complete actual image bytes>"}. Ask front/back BEFORE calling if unknown. Exactly one user-provided public HTTPS image URL (port 443) or complete base64 source, never both. Never decode, repair or re-encode bytes yourself; never invent, shorten or rewrite base64; pass it verbatim, including an image data-URL prefix or whitespace (service normalizes). If chat attachment cannot be forwarded, send user to https://centeringlab.com/. card_size standard=63×88 mm including Japanese Pokémon; small=59×86 mm including Yu-Gi-Oh!, not inferred from language. Request a whole card flat from above on dark surface; if sleeved/toploader or tilted, recommend a retake first. Borderless: suggest back/manual site. API photos reach server memory; site stays local. needs-review/failed gives ceilings=null: retake or adjust manually, no grade prediction. Inspect status/code even on HTTP 200; respect Retry-After.