Pocket

In roulette, the pockets are the numbered compartments around the rim of the wheel where the ball finally settles. The count and arrangement of these pockets determine the house edge, which is why the wheel's design, rather than any betting system, is what ultimately fixes the odds against the player. A European wheel has 37 pockets, numbered 0 to 36, with a single green zero. A straight-up bet on one number pays 35 to 1, yet there are 37 possible results, so the true odds are 36 to 1. That gap between the payout and the real probability produces a house edge of 1/37, or 2.70%. Over time, a 1 stake on a single number returns, on average, about 0.973. An American wheel adds a second green pocket, the double zero, for 38 pockets in total. The straight-up payout stays at 35 to 1, but the extra pocket lengthens the true odds to 37 to 1, lifting the house edge to 2/38, or 5.26%, nearly double the European figure. The only structural difference is that one additional zero, and it almost doubles the long-run cost to the player. The practical lesson is to prefer single-zero wheels wherever both are offered, since the same bets cost far less against a European layout, and French tables with la partage or en prison rules cut the even-money edge further still. A common mistake is believing that betting more pockets, or chasing numbers that have not appeared recently, changes the maths. Each spin is independent, and the pocket count, not the pattern of past results, governs the edge.