Roulette is a casino and gambling game (Roulette is a French word meaning small wheel). A croupier turns a round roulette wheel which has 37 or 38 separately numbered pockets in which a ball must land. The main pockets are numbered from 1 to 36 and alternate between red and black, with number 1 being red. There is also a green pocket numbered 0. In most roulette wheels in the United States but not in Europe, there is a second zero compartment marked 00, also colored green.
If a player bets on a single number and wins, the payout is 35 to 1. The bet itself is returned, so in total it is multiplied by 36. (In a lottery one would say ‘the prize is 36 times the cost of the ticket’, because in a lottery the cost of the ticket is not returned additionally.) A player can bet on numbers, combinations, ranges, odds/evens, and colors.
Types of Roulette
There are two types of roulette, American roulette and European roulette. The difference between the two types is the number of 0’s on the wheel. American roulette wheels have two “0’s”, zero and double-zero, which increases the house advantage to 5.4%. In European roulette there is only one zero, giving the house an advantage of 2.7%.
The two versions use chips differently also. American roulette uses so-called “non-value” chips, meaning that all chips belonging to the same player are of the same value determined at the time of the purchase, and the player cashes in the chips at the roulette table. European roulette uses standard casino chips of differing values as bets, which can make the game more confusing for both the croupier and the players.
A traditional European roulette table is also much larger than an American roulette table, and the croupier uses a long tool called a rake to clear out the chips and to distribute winnings. In American roulette the croupier collects and distributes chips by hand.
Betting only on red
One conceivable strategy would be to bet on the ball landing in a red space for a certain number of spins, for example, 38.
There are 18 red spaces on a roulette table with 38 total spaces. Dividing 18 by 38 yields a probability of landing on red of 47.37%. This probability can be used in a binomial distribution and made into an approximate standard normal distribution.
Doing so indicates that, if one were to spin the wheel 38 times, there is a 99% probability that the ball would land on red at least 10 times. There is an 83% probability that in 38 spins, the ball will land on red at least 15 times. Out of 38 spins, there’s a 50% chance that 18 will be red.
However, the break-even point is 19 spins, since the bet on red is 1:1, and the probability of 19 red spins in 38 is only 37%. This indicates the difficulty of winning by only betting on red.
The results occur because, as indicated by the 18 divided by 38 equals 47.37% figure, the ball will land on red less than half the time. This percentage applied in the binomial and standard normal distributions creates the vast divide in probability from 18 red spins to 19 red spins out of 38 spins. Basically, it is very unlikely for anyone to spin much more than 18 red spins out of 38 spins.
Betting multiple times
This type of bet is a combination of the red bet and the martingale system. Except this bet also includes the odd. What you do is you start off with a bet of 1 on each the red and the odd (or you can do the black and even). You treat each bet separately. When one bet loses, you double it. When one bet wins, you set it back to 1. The reason that this technique keeps you in the game so long is that there is almost a 25% chance of you winning both the red and the odd and there is almost a 50% chance that you will break even (win one bet and lose the other). Of course in order for this method to last, you would need an unlimited source of money. Also, in the long run, because the house still has an edge, you will lose money just like with all other unbeatable casino games.
Using the dozen bet
There are two versions to this system, single dozen bets and double dozen bets. In the single dozen bet version, you use a progressively incrementing stake list starting from the casino table minimum, to the table maximum. The aim here is to use a single dozen bet to win before the stake list ends. Many techniques are employed such as: betting on the same dozen to appear after two consecutive appearances, betting on the dozen that has appeared most in the last 15, 9, or 5 spins, betting on the dozen that, after a long absence of 7 or more spins, appears for the first time. The double dozen bet version uses two dozen bets and half the stake list size of the single dozen bet version.