BGS submission prep: a hobbyist's guide to Beckett.

Where PSA reports a single composite grade, Beckett Grading Services scores each card on four sub-grade categoriesand prints all four on the label slab underneath the overall number. Knowing what each one measures is the first step to reading a BGS grade — and knowing how to argue an overgrade when the numbers don't match the corners.

The four sub-grades, in plain English:

• Centering — how evenly the artwork and borders sit within the cut. Measured left-to-right and top-to-bottom; the printed score reflects the worse of the two axes (typically expressed as a percentage ratio). Off-center Mint cards are the most common reason a visually flawless card lands at 9 instead of 9.5.
• Corners — sharpness of the four corners. BGS scores the weakest corner, so one visibly soft corner pulls the sub-grade down even if the other three are perfect.
• Edges— the chipping, whitening, and frosting along the card's perimeter. A scuffed edge from binder pull can drop an otherwise Mint card to 9 without touching corners or surface.
• Surface— print defects, scratches, dimples, and wax stains on the face of the card. Centering, corners, and edges can all come up 10 and the card still won't grade 10 if there's a print dot in the gloss.

Each sub-grade is reported on the same decimal scale as the overall composite — whole numbers plus halves, 1 through 10 in 0.5 increments. The four sub-grades, plus the overall composite, are the five numbers printed on the BGS label slab.

The single most-misread rule in hobbyist BGS grading: the overall grade is the lowest of the four sub-grades, not an average. BGS uses a weakest-link rule. A card with three perfect 10 sub-grades and one 9 corner grades 9 — not 9.75, not 9.5. The composite rounds with the floor, not toward an average.

This is the source of the famous hobbyist-headline outcome: a visually flawless card with a single soft corner lands an overall 9, and the seller argues "but three of the four are 10!" — under BGS rules, that's a 9 because the corners sub-grade is the lowest of the four. The math isn't negotiable.

Most hobbyists learn this rule the hard way when their first BGS slab comes back a half grade below the card's visual condition. The fix is asking which of the four the labels graded lowest and reading the slab accordingly — the sub-grade tells you which category to inspect next time.

Beckett runs six grading tiers — premier, express, standard, economy, bulk, and walk-through — and the declared-value requirement is set by tier and per-card value. BGS requires a declared value when you submit on the premier tier, and also requires it whenever a single card is declared over the published threshold.

Slabwright encodes that rule at fee_schedule.declared_value_required_above_usd: 500— any single card whose declared value lands above $500 requires the field regardless of tier. That's the two triggers worth knowing:

Slabwright's mapper reads the canonical declared-value column and flags every blank row that crosses the threshold — same pattern as the PSA fee tier guide, the only difference being the threshold and the trigger tier list.

The set of columns Slabwright writes to a CSV for BGS comes straight from schemas/bgs.json, which is the same authoritative column set the schema preview tab and the upload island already consume via /api/psa-schema?grader=bgs. Pick BGS in the upload dropdown and Slabwright validates your file against those exact columns.

The walkthrough, in the order the columns land on the BGS form:

• sport, year, brand, set-name — the four required identifiers. sport is a closed enum (Baseball, Basketball, Football, Hockey, …, Non-Sport) and BGS rejects anything outside the list on submit.
• card-number, variant — optional print-run shape: #247 or Gold /99. Leave blank for unnumbered cards.
• player-first-name + player-last-name — the first BGS quirk worth internalizing. PSA uses one Playercolumn; Beckett splits the subject across two columns. Slabwright's mapper handles that split automatically when the grader is set to BGS — both fields land correctly on the label slab.
• card-condition — the second BGS quirk worth internalizing. Closed enum of Raw and Pre-graded. A Pre-graded row also requires thegradecolumn to be populated with the existing BGS grade in 0.5 increments — Slabwright's error flagging panel catches a missing grade on a Pre-graded row before you pay or print.
• declared-value — owner-declared USD value. Required when grading on the premier tier or when a single card is over the $500 threshold (see the declared-value section above).
• quantity, notes, cert-number — quantity is per-row (BGS models quantity explicitly, where PSA bulk shipments model it via repeated rows); notes is free-text for autograph verification and special qualifiers; cert-number is blank on first submissions and populated on re-submits.
• ordering— auto-generated. The mapper writes the 1-based row order; never map it from your CSV header or you'll collide with the mapper-written one.

The full column set lives at the BGS mapper — pick the BGS pill on the upload page and the schema preview tab renders the same fifteen columns from schemas/bgs.json.