What is the roulette wheel layout?
The numbers on a roulette wheel are not arranged in numerical order. They’re placed in a deliberate sequence designed to distribute red and black evenly, alternate odd and even numbers as much as possible, and spread high and low values across the wheel.
European wheel sequence
The European wheel runs clockwise: 0, 32, 15, 19, 4, 21, 2, 25, 17, 34, 6, 27, 13, 36, 11, 30, 8, 23, 10, 5, 24, 16, 33, 1, 20, 14, 31, 9, 22, 18, 29, 7, 28, 12, 35, 3, 26. The American wheel adds 00 and uses a different sequence with the two zeros placed directly opposite each other.
Why the layout matters
The physical wheel layout is the basis for called bets like Voisins du Zéro and Tiers du Cylindre, which cover specific arcs of the wheel rather than sections of the number grid. When a roulette ball is known to favour a particular sector of the wheel due to wear or tilt (known as wheel bias), knowledge of the sequence lets a player target those numbers. In regulated casinos wheels are regularly tested to prevent this, but the layout remains the reference point for sector-based betting strategies.