In the short term it depends on luck and time factors but as far as the long term experience is concerned it completely depends on your knowledge and practical exposure ofcourse luck is a strong factor but practice makes it perfect .Even the best gamblers had to lose all their chips at times regardless of the luck or exposure .Fact is its gambling, its a short cut!
Why do you say even the best gamblers had to lose all their chips at times? You mean losing their entire bankroll? I never heard most professional gamblers to say anything like that. Most of them in poker and sports betting say that they started low, and just kept going and now can make a steady income with that. They win and lose of course, but never went bankrupt.