For a game that relies on the whims of Lady Luck and Dame Fortune, roulette has inspired quite a lot of people to invent roulette systems that are "guaranteed" to work. But despite the simple mathematics that governs most roulette games, there is no such thing as a perfect roulette game system. Reason number one is that you cannot alter the house advantage of 5.26%. Reason number two is that no roulette system can accurately determine the outcome of each spin.
Roulette System: Probability Theory
Some authors base their roulette systems on probability. Now, while this kind of roulette game system works perfectly in poker games, in roulette, it's not likely. Probability in a roulette system works by determining all the possible outcomes through the process of elimination.
So for instance, you make a Straight Up bet on 35. The first spin shows you 31. In the next spin, it doesn't mean that you only have 37 odds left since you subtracted 31 from your 38 possible outcomes. It's quite possible that the next spin will result in the same number, the number 31.
This is why a roulette game system that is based on pure probability will not work. In theory, perhaps this roulette system works but in practice, it's not likely and you'll end up losing more than you intend.
Roulette game System: Martingale
Several roulette systems are variations of the martingale system, which is basically a "double up until you win" approach to gambling. In its simplest form this type of roulette system tells you to double your bet after each loss until such a time that you encounter a winning spin. In this roulette game system, your final winning bet will make up for the money you lost in all the previous bets and give a profit that is equal to your original bet.
For example, you bet $5 and lose the first spin. Using the roulette system based on the Martingale system, you double up the bet to $10, $20, and then $40, which total up to $75 worth of losses. On the fifth spin, you double your wager from $40 to $80 so now you have $155 at risk. However, you get lucky and win, earning you a profit of $5. Sounds good, right? Wrong.
This roulette game system only works if you have an infinite amount of money and an infinite amount of free time. Sure, it is true that you would eventually win. That's the thing with luck. It comes and it goes but to wager all you've got on that one time win is a complete waste.