Roulette is a popular casino game that involves a spinning wheel and a ball. The probability of winning in roulette depends on the type of bet placed and the specific rules of the game variant, such as European or American roulette. The basic probability formula for a single number bet in European roulette is P = 1 / 37, since there are 37 pockets （numbers 1 to 36 plus a single zero）. For American roulette, which has 38 pockets （including a double zero）, the probability is P = 1 / 38. 
To calculate the probability for other bets, such as red/black or odd/even, the formula adjusts based on the number of favorable outcomes. For example, in European roulette, the probability of betting on red is P = 18 / 37, as there are 18 red numbers. The general formula is P = （Number of Favorable Outcomes） / （Total Number of Possible Outcomes）. This helps players understand their chances and make informed decisions while playing. |
