[cspen]

Who decides what constitutes a RC? Topps puts the logo on cards that Beckett does not designate as RC's in the pricing.

[uvaspina]

It's my understanding that MLBPA decides who the RC logo-eligible players are--and they provide the list to Beckett and to the card companies. Basically, since 2006 (when the rules changed), a true rookie card--designated as "(RC)" in Beckett, is the player's first base card in a nationally-distributed set for the year in which they've been assigned rookie status. Inserts don't count (in Beckett); parallels don't count (in Beckett)--even where the card itself bears the "RC" logo.

[djohn]

Card companies can put the RC logo on any card of a player during his rookie year (as defined by MLB). I know Topps likes to put the logo on some inserts and subset cards, which Beckett doesn't define as RCs.

[hckydv7]

And the Topps Update cards that say "Rookie Debut" are also not RC because they have another card in that set.

Also, players may have a RC designated card marked as such BEFORE his rookie year.
He just cannot have a RC logoed card until after he plays at least 1 game. A player can have less then 130 at bats or 50 innings pitched or less than 45 days on the active 25 man roster and still be counted as a rookie the next year.