How about following, once you start winning frequently and casino persistently ask you not to gamble (kick or ban you), then this means you have beaten casino. Since it is impossible to win all the money casino has, since casino income grow more and more with each bet, the moment when casino becomes scared of you and kick you out, it means you have beaten it and they get rid of you.
The problem is that I have never been able to reach the point where the casino would try to kick me or ban me, in fact I have been so unsuccessful that I intentionally asked to ban myself for life from a certain casino that I am not naming their name here again, I have named them enough in many other threads of mine and most people know who they are. The casinos nowadays, those well established and running with a lot of positive feedback from quite a long time they don't need to kick anyone, even people who win like 500.000 dollars or more as they have enough budget and they will make that money back in a very short amount of time.
I find it strange for people being able to beat the casino since this in theory it is totally impossible in the long run.