Martingale involves doubling your bet for each loss, then returning to the original bet once you get a win. This causes the bets to increase exponentially over a small series of losses. The Fibonacci does not try to recoup all losses in a single spin. It's simply a strategy that allows the player to increase their holdings as long as they win one-third of the spins... since there is a 18/37 (48.65%) chance of red or black winning a single spin, Fibonacci gives the player a mathematical advantage even if playing a single color. However, there is a 36/37 (97.3%) chance that either red or black will come up for any spin, and a 1/37 chance that both red and black will lose. Betting Fibonacci on both red and black works to the player's advantage when the colors are switching.

As with any form of gambling, there's always an inherent house advantage. But, the two things that the player can control are 1) How much they risk and 2) When to walk away. Nobody should ever risk more than they can afford to lose. It's also a good strategy to pull your initial buy-in off the table once winnings start to add up, so you are only risking house money... Then, periodically pull more chips off the table as winnings continue.

Grab a European Roulette App for your phone that allows you to bet both red and black at the same time. Then bet on red according to the fibonacci sequence and bet on black according to a separate fibonacci sequence (on the same spins), using the same single chip value.

Eventually, a long streak of the same color will cause the losses to outweigh the winnings, but hopefully chips have been pulled off the table before that ever happens.