So you gambled online for 6 years but couldn't google for some math?
(wizardofodds.com has great information on gambling and odds)
There is not betting system that will beat a game with a house edge, negative expectation or whatever you prefer to call it. The Martingale system will make you lose more money than flat-betting. If anyone thinks otherwise he is welcome to put his money where his mouth is and I'll take a bet of any size, that his betting system does not work.
There is a way to beat online casinos of course, since they give out 100% or higher bonuses. The house edge will only eat from your bonus as you play towards the wagering requirements.