If you look for black players in MLB, expect them to be from the Caribbean nations. If you look for white players in the NBA, expect them to be from the Eastern European nations. There are exceptions in both cases, but they are exceptions.
What the hell happened to US-born white guys since the 60’s / 70’s when white players were still a majority in the NBA ?
Pretty simple. U.S. born elite black athletes go into basketball and football. More opportunity to see fame and fortune.