Anyone that collected during the boom of the late 80’s and early 90’s will remember the monthly Beckett Price Guides, with full lists of card values of all of the popular sets of the day. Beckett created BGS in 1999 and is one of the 2 most sought after ‘slabs’ along with PSA.
Beckett has multiple streams of their grading services with BGS handling their modern era cards (1981 to present), Beckett Vintage Grading for cards prior to that, and then Beckett Collectors Club Grading which uses a simplified grading scheme.
Beckett also uses a 10 point scale, but they have a 9.5, which they refer to as Gem-Mint. Their regular 10 is referred to as Pristine, while a card that gets a 10 on each sub-grade (Centering, Corners, Edges, Surface) gets the rare ‘Black Label’ distinction.
All of their graded cards have a serial number so you can track the validity of graded cards on the secondary market.