If you do not want to think too much about the roulette system or the strategy you want to play, the Martingale strategy will suit you. This ensures that you cannot continue to redouble your bet. For a lot of roulette tables, a maximum bet applies.
In theory, you would always win (if your bank account is large enough to use unlimited funds). In fact, it means that you always double your bet if you have lost your previous bet. It is often used by novice players who choose to play on for example odd / even or red / black. One of the oldest roulette systems that can help you to play online profitably in the casino is the Martingale system.