I don't even know what will qualify an individual as a professional and if it is being knowledgeable in different gambles, they I should have been awarded a professional. I don't believe in that idea of a professional gambler because the moment you gamble consistently and is able to manage gambling addiction, there are high chances that your knowledge in gambling will increase and you start to make informed gambling decision. Maybe at this point you can be called a professional gambler.
Who verifies there is a professional gambler, how is the standard? This is a big question in my head as a gambler, is he who has a long experience in gambling or what?
If you look at professional standardization then he has serious expertise in that field, of course his victory should be much greater than the defeat and history is much more victory.