The concept behind progressive roulette betting systems is that when you finally hit on a number, you will win more because you have been progressively betting more with each bet after a losing spin. Although the odds are against the player in roulette, the payouts for many bets are high enough to where the system would seem to work, provided you have a big enough bankroll to carry you through the long streaks of no wins.
The most famous of the progressive roulette betting systems is known as the Marginale System. This system is used only on the near 50/50 bets such as red and black. Basically, the concept is that after each losing bet, the next bet is exactly double the previous one. For example, if the first bet is $1 on red, and you lose, the next bet is $2. If that loses also, then the next bet is $4 and so on. The problem is that if a gambler hits a long streak of losses the bets get very large, very fast and they stand a chance of bumping up against the table limit on bets at which time the system falls apart. Therefore, the wise gambler will choose a table with an extremely high limit if attempting to use a progressive roulette betting system.
A way to lower the possible downside on any progressive system based on raising the bet when a loss occurs is to limit the string of bets. For instance, the gambler may establish a predefined number of losses, after which he will go back to the original bet.
Another progressive roulette betting system takes the opposite approach, raising the bets each time a win occurs. Some believe that this system is superior to the Maringale since the majority of betting will be done with winnings rather than a gamble's own bankroll. One example of this system would be to bet one chip on each of five numbers, continuing until one hits. At that time, increase the number of chips on each bet to two, continuing at two until all thirty of the chips that were won are gone or until another winning number is hit. If the gambler goes through the amount of the winning without hitting again, the bet drops back to one chip. If a number is hit before the gambler has gone through the winning, another chip is added to each bet, making it three, and this number of chips is continued until all winning are exhausted, at which time the bet drops back to one again, or another win occurs, when the bet is again increased. And so on.
Progressive roulette betting systems can minimize the risk a gambler incurs, but careful attention should be paid since gambling is "streaky" and the losses can mount up fast.