Rookie sports cards Retro modern Basketball Football Motorsports and much more

Rookie sports cards basically first year as a top professional , many times a player will be known such as Ivan toney Gareth Bale there rookies are brentford and tottenham,  Bellingham Borussia Dortmund ,  but ACTUALLY THEY PLAYED FOR Southampton AND Birmingham First , and same with Luka Doncic his true Rookie would be Real Madrid but unsure why as Spain is a top league but only NBA counts as Rookies, so even more crazy than Football , and again with Motor racing f1 will be the rookie, f2 and karting series don't count, i think strangest still is Thierry Henry his rookie is known as the 1999 Arsenal card, yet he actually played for France , Monaco and Juventus before so all quite confusing