Is been responsible with gambling all it takes to be a professional gambler or someone needs to win in the process many times already to be considered a professional gambler?
To be called a professional gambler, it is enough that gambling is your only source of income (means of existence). Of course, an unemployed person who has won his last $100 can't be called a professional gambler. That is, these incomes must be at a sufficient level to ensure life (a rather "vague" and "stretchy" interpretation).
I have always win less, no reason to lie but I get curious when I see gambling related posts online about people pointing to some gamblers calling them professional and the only vital point of this all is because they won many times in their own way.
In general, these people are right. Many victories are already a demonstration of the presence of "knowledge and skills" that allow you to "earn" on gambling, as if it were a job.
What is a been qualified as a professional gambler in your own world? The winning part or the responsible part of trying to avoid addiction is all.
This means systematically finding yourself in financial profit in gambling activity, allowing to have a stable financial position.