Luck will always be on the side of those who work or make a living from gambling income, because they will try to master the game and will continue to play to earn income for their needs, and this happens to my close friends and even he has more income than me who has permanent work.
and as long as he enjoys and always earns income from gambling he will continue to play, and only God will change it because it has become his way and plan and there will be a good time to change it at the right time.
Are you serious about this?
Luck is invisible, you can't predict whether this person will get lucky or not because it's very random. Even you're full of hard work and put so much effort into your passion, if there's no luck then you will still strive more to get another luck. Winning and being successful in gambling is pure luck, no one can get a winning streak in the whole year unless the person is cheating or controlling the house.
You didn't consider the other factors your friend has so he/she keeps winning. It's not about luck, it's your idea and strategy also but luck has the huge factor of winning.