Wheel Mechanics & Basic Terms
European Roulette: A roulette wheel with 37 numbered pockets (0-36), offering a house edge of approximately 2.7%. This variant features a single zero, providing better odds for players compared to American roulette.
American Roulette: Contains 38 pockets, including a 0 and a 00, resulting in a house edge of 5.26%. The additional double zero significantly increases the casino's mathematical advantage.
Pocket: The individual numbered compartments on the roulette wheel where the ball lands. Each pocket corresponds to a number between 0 and 36 in European roulette.
Ball: The small sphere spun in the opposite direction of the wheel. Its landing position determines the winning number for each spin.
Probability & Odds Terminology
Probability: The mathematical likelihood of an outcome occurring. In European roulette, the probability of landing on any specific number is 1 in 37, or approximately 2.70%.
Payout Odds: The ratio of winnings to the original bet. A straight bet pays 35:1, meaning a successful $1 bet returns $36 total ($35 profit plus original stake).
House Edge: The mathematical advantage the casino holds over players. In European roulette, the house edge of 2.7% comes from the presence of the zero pocket, which is neutral to player bets.
Expected Value: The average amount a player expects to win or lose per bet over many spins. Negative expected values indicate games favor the house.
Betting & Wagering Terms
Straight Bet: A wager on a single number, paying 35:1. This offers lower probability of winning but the highest payout ratio.
Even Money Bet: Wagers on red/black, odd/even, or high/low. These bets pay 1:1 and have approximately 48.6% probability of winning in European roulette.
Inside Bet: Bets placed on specific numbers or small groups of numbers within the betting grid, including straight, split, corner, and line bets.
Outside Bet: Bets on larger groups of numbers with better odds but lower payouts, such as dozens, columns, and even/odd wagers.
Spin: One complete rotation and landing of the roulette ball, determining one outcome and settling all related bets.
Advanced Mathematical Concepts
Variance: The degree of fluctuation in results around the expected value. High variance means larger swings between wins and losses in the short term.
Standard Deviation: A statistical measure showing how much results typically deviate from the average outcome, helping predict the range of possible results.
Law of Large Numbers: The principle that actual results converge toward theoretical probabilities as the number of trials increases significantly.
Gambler's Fallacy: The incorrect belief that past results influence future independent spins. Each roulette spin is independent with identical probabilities.