I known lots of people who earn their living in a Casino. It is a matter of right strategy in every session I guess. I have talked to one of them and told me that it is a matter of discipline and planning when to quit. Though this person said that he does not win all the time but he is sure that he is raking profit in his career as a gambler.
Whoever told you that they could make a living out of a casino that has house edge in the games is lying. It is literally impossible mathematically to keep profiting. Even if you profit for 10 years, eventually all that 10 year will be lost one day since house edge ALWAYS takes your money back. If you decide to trust, well just go ahead and try yourself, put your money in there and keep working to make a living out of casinos and you will soon realize why I am saying that person was lying. There is no strategy, there is no mathematics, there is no methods, it is mathematically impossible.
To make it easier to understand let me say it like this, everyone says 2+2 equals 4 and your friend told you that "no sometimes it can be 5" and you believed that, just don't.
Nope, they are not, they are professional gamblers that know what to do, they are living well. House edge kicks in(hurts) when you are playing too long in a single session. Try to observe it and you will understand what I am saying.
These people do discipline themselves. For example, if they win around $300 they will stop and play again another day. And on a very unlucky day, they make sure that they won't lose more than what budget they have set on that session. With the method they use, it is very impossible for them to lose all their savings in a single session.
I do not really have to prove anything beyond house edge to anyone, I have already told you previously that gambling against the house edge is literally the reason why nobody could make a living out of gambling.
There is no extraordinary claim here, it is factually the standard, every single on earth knows what house edge is and why casinos make billions of dollars in profit whereas there is no person who can keep gambling and keep making profit. This is literally the fact of house edge, MATHEMATICAL impossibility of making a profit.
If you still want to argue about this, I would love to point towards house edge as my reasoning and expect you to find me just ONE person who has constantly made a profit for a year, just one year in life (and you need to make money for 50 times that but let's ignore it) where one person has made profits overall.
If you can provide me with proof of ONE person making profits for ONE year, I will change my mind. If not, then house edge is the winner. I know nobody can do it, because MATHEMATICALLY IMPOSSIBLE, what part of house edge nobody understands?