This is how the old French game of chance roulette works.
Roulette is not only perhaps the best known and most widespread game of chance in the world, no it also enjoys a very special popularity and is considered by many to be particularly fair. Simply because the chances of winning are higher than in many other casino games. If you always bet only on the colors black or red, until the croupier calls “rien de va plus ” (nothing goes anymore), then the chance of winning is almost 50 percent.
But how exactly does it work?
In the so-called roulette wheel the numbers from 1 to 36, plus a green zero are arranged in a fixed order. There are 18 red and 18 black numbers each. Later, a ball rolls through this pot and the player has to predict on which number he thinks the ball will come to a stop.
Here there are now different possibilities to bet, which all have their very own probability to occur. The simple possibilities here would be:
even or odd
red or black
low or high
With these the probability for one to win is then 18/37, or better said 48.6%. If you win here, you get your stake and the value of the stake on top as the winning sum. Here, by the way, the bank wins only in one of 37 cases, namely when the ball falls on the zero and thus none of the easy chances wins.
Because of exactly this quite small probability to win for the bank, roulette counts to the particularly fair gambling games and some casino operators go even beyond this measure. If you bet on a simple chance and you get a zero, you still keep your stake and you don't lose anything, as long as the bet comes in the next round.
Of course there are also more possibilities than the simple bet, these are:
Dozens, one bets on one of the 3 possible dozens and in case of winning (12/37 = 32,4 %) receives 2 times the stake
Transversal simple, you bet on the 6 numbers of two consecutive cross rows and receive 5 times the stake in case of a win (6/12 = 16.2 %)
Carré, you bet on 4 adjacent numbers and in case of a win (4/37 = 10.8 %) you get 8 times your bet
Transversal pleine, one bets on the 3 numbers of a cross row and receives in the case of profit (3/37 = 8,1 %) the 11-fold employment
Cheval, you bet on two adjacent numbers and get 17 times the stake in case of a win (2/37 = 5.4 %)
Plein, you bet on one of the 37 numbers and get 35 times the stake if you win (1/37 = 2.7%)