Let’s start with roulette playing systems – they are the most popular on the market. These systems appeared almost after game creation immediately, many stakes variation systems appeared some hundreds years ago, but till nowadays most of modern systems base on it. Though for all these hundred years we can’t remember cases of casino’s ruin by strategy roulette-men bands, but new players don’t daunt with it, they apparently believe that in 200 years system will work with them personally J.
The most popular stakes variation system is Martingale surely. It appeared in 18th century even, however it seems to be named for 19th century player (but I didn’t find common opinion in sources). The essence of system is the following – you stake 1 on chances (for example on red). If you win – that’s great; your outcome is +1. If you lose, stake on 2 next. You win – your outcome for two spins is -1+2=+1, stake on 1 again. You lose, double your stake again, now stake on 4. If you win you are in plus for one again (-1-2+4=+1) and back to initial stake on 1. When lose every time double your stake, 8, 16, 32, 64 etc. When win you’ll compensate all your losses and stay in plus equally on one, after what you back to initial stake and all starts over again.
The systems seems to be sure – as you can’t lose infinitely, and the first winning gives you plus. Unfortunately for players losing series can last rather long time, so the probability that necessary colour will not occur ten times is about 1 to 1600, and your stake in this case have to be 1024, and 1023 you’ll already lose to that moment. 1600 spins is one day of game, and you already need 2000 units’ bank to secure you without-lose game. It is doubtful whether you have so much money.
And else there is a table limit in casinos, stakes limit is 1-100 units usually. So, Martingale will stumble on eighth step already (you’ll can’t stake 128, only 100, and if you’ll win, you’ll stay in minus on 28).
So, Martingale system is like sphere horse in vacuum – win only with your endless bank and without table limits, and in real conditions it doesn’t change expectation value in roulette giving the same -2,7%.
I’ll mark that system, which seems as sure for somebody up to now, with little bank will lead you to crash faster than flatbet game (equal stakes).
The resume is the one: there are no systems beating roulette! -2,7% stays on distance whatever system you’ve used! At least if roulette is chance, and there is high-quality random number generator in online casinos, roulette will be random as a result. If you’ll hear that “without-loss” system works “by the law of big numbers”, “2/3 law” or even “on correlation of continuum fluctuations and player’s psychophysics” – run away of swindlers like of fire.
Theoretically it is possible to beat real roulette, if it works overtime and acquires “inclination” (look Jack London “Smoke and Shorty”) or becomes more predictable by other reason. But I’ll repeat, in online roulette systems don’t work and cannot work according to probability theory laws!!!