Most people don't understand the basics of statistics and blame everything on "unfair games". Gambler's ruin theorem is known for many centuries and it's really simple - in the long run player with smaller bank will lose. That's why all casinos pursue giant bankrolls and like to take investments.
I don't think with big bankroll we can beat casino and i think small or big bankroll to start gambling is have same chance to win. for example you can start to bet with 5% from your bankroll so you have chance win more big than you start with 20% from your bankroll.It's easier to understand this concept if you look at fair coin toss simulation. It can look like this:
- is players loses, + is players profit.
Now, I've drawn 2 lines. When players loses are equal to his bankroll the game stops, which is seen here as the red line. The house can also go broke, if players profit is higher than their bankroll (yellow line).
So, the likehood of losing all bankroll is determined by the size of bankroll. If you have 1000 BTC and play in casino with 10 BTC bankroll, you have 99% to "beat casino" and take their 10 BTC.
You can also look at any casino and check their profits, they are always much bigger than house edges, because their bankroll is bigger than sum of players bankroll.