This seems like a good plan and one that might work if you “win every day.” Unfortunately we can't win every day and we lose more

I have done something like that. Withdraw 80% of the funds and leave 20%. However, it didn't go according to plan because the remaining balance ran out again, then I deposited again and it ran out again. So it's very difficult to keep winning, I've been trying to stop for a week but when I  gambling again, I keep losing.

The only way that works for me is to gamble when I have extra money and not to gamble if money is tight or I have other needs. It looks simpler and doesn't require a lot of complicated setup