The first reality which any forward-thinking roulette player must come to terms with – as counterintuitive as it may seem – is that pattern systems simply do not work as strategy in this game. Roulette is purely a game of chance and therefore each individual outcome is entirely independent of previous results.
Got it? Good. To test your knowledge, then, consider this theoretical: A roulette wheel pays out on the number 20 five times consecutively. The odds of hitting the number 20 for a sixth time is: a) longer than the usual 37/1 odds, b) shorter than 37/1, or c) exactly 37/1. The answer is of course (c), and the odds of a seventh 20 result would again be 37/1.
Despite the mathematical reality, however, roulette "systems" still exist and are sold to the unsuspecting. Among the more common systems in the gaming public's collective consciousness are:
The Martingale Strategy. In this one, the player wagers a bet of X. If he/she wins, the same bet is made again. If he/she loses, the next bet will be 2x. With this strategy, the player will eventually recoup all losses plus earn a profit equal to the original bet. Of course, several unlucky spins in a row makes the player bankrupt more quickly than in casual, "system"-free betting.
The Labouchère System. A modification of the Martingale strategy, this one relies on a system of recalibrating wagers so that bets don't rise as quickly as in Martingale fashion.
The D'Alembert System. Yet another spinoff on the Martingale, the D'Alembert is based on a simple pyramidal mathematical formula. The player makes a bet; if he/she wins, the proceeding bets is 2x. On losses, the next bet becomes x-1. Unfortunately, the math here is shaky and depends on even distribution of winning and losing spins.
Finally, there's the "Dopey Strategy" once devised by Andrés Martinez of the Los Angeles Times. The player simply divides his/her roulette bankroll into 35 equal amounts and plays the same single number up to 35 times. Any win ensures that the player turns a profit and the odds of hitting are over 60%. Of course, this isn't a very exciting way to play…