Eg start instruments or sports very early, can afford top tuition, often a parent has the skills to teach the dc at home, they have the time & money to travel around the country for events.. Parents oversee practice is done at home.. Whereas they may well be quite medicore compared to a child with raw talent whose parents just cannot afford what it takes..
I just feel for music, sports or academics money & an affluent background is part of the parcel for the majority of "gifted kids"..