The point is to be a successful gambler, at least know when to gamble and know when to stop gambling because that way we can control ourselves well and consider gambling to be just entertainment, a place to have fun, another thing that is most important to do is limit budget as well as time when gambling so that you don't get too addicted to gambling because it is a disease that is difficult to cure and not many people even recover from gambling addiction, always remember this message, never gamble if you can't control yourself and know when to stop gambling.
Uhmm I'm not sure if someone can actually become "successful" in gambling when the lossing ratio is far more than the number of times you could win.
I'll have to call it responsible gambling instead, it's a method where you have full control over everything. Your time spent in gambling, the money you're willing to burn in gambling, and the estimated losses you will incure everytime you gamble.
There would be no time frame on how long you should gamble and stop specifically within a period of time, but it will depend whether you exhaust yourself or your budgeted money for gambling.