The Fibonacci number sequence wasn't designed to become a roulette betting pattern, but has been adapted to the roulette game nonetheless. This betting system can be applied to even chances bet (red/black, odd(even, low(high). Fibonacci number sequence is a series of number in which the next number is the sum of the two previous numbers. It goes like this:
1-1-2-3-5-8-13-21-34-55-89 and so on.Used as a roulette betting pattern, this progression is much safer than the Martingale System (which double the bet at every loss), as a downside, the Fibonacci roulette system doesn't always give a profit.
Actually, if you win the first bet, you gain a profit; if you win the 2nd or 3rd bet you break even; starting from the 4th bet, you'll always be in minus.
So we can say that, using the Fibonacci roulette betting pattern, there's no much profit to be gained. However, you can overcome the shortcoming of this roulette system by going back 2 stages in the progression when you win (thus going back to the start, when you gain profit).
For example, if you proceed in the betting progression until you have to bet 21, and you win, your next bet should go back 2 step, thus you should bet 8; if you win again, your next bet would become 3.
This way, you will only need half as many wins as you get losses to gain a profit at online roulette. The downside to this roulette betting system is that if you hit a losing run, your bets will go high, consuming your bankroll, so that you won't be able to recover from the losses.
It's important, when using this roulette betting pattern, to determine beforehand a stop loss limit, and stick to it.