When I told a friend that a stray dog had given birth to 9 puppies she said among the 9 there will be a "king" and it will be very good to own that one. How to identify, I don't know and I think neither does she. Perhaps it will be outstanding physically or mentally? Maybe exceptionally faithful? More loyal? No idea but I managed to get Wawa, the sickest and tiniest of the lot and compared to his siblings who have died or been abandoned he sure is living like a KING in my house!