We can never be sure of the luck that you will receive, knowing that you could try to make a ritual or something. Maybe they are the ones who are lucky because it's the first time or something. You would never know how you could be so sure with things in your life but that could be something that could change your life if you treat it in a different way.
But how would you explain that every time that my cousins will play color/number game, they always win something, even a small thing they can get. I don't know why they are doing it, and I don't know if ritual is true, but maybe they are truly gifted in terms on that game. LOL. 
It is simple to guess that your cousins are lucky ones in this game. Or may be they are expert in this game. Actually every gambler is usually expert in one game, whenever he play it usually he has a lot of chances to win in own game. Like whenever i play sports betting then mostly i win but if i play poker, i can't win in it, even i never win a signal game in poker since now.