Part I: Games & Gaming · Wheel Games — Roulette

Wheel Bias

Roulette

A condition in which a roulette wheel produces non-random results, causing certain numbers or sectors to be hit more frequently than statistical probability would predict. Wheel bias can result from mechanical defects such as worn bearings, uneven pocket depths, loose or damaged frets, irregular deflectors, or an unlevel wheel. Historically, wheel bias has been exploited by advantage players (most famously Joseph Jagger in 1873 and the “Eudaemonic Pie” group in the 1970s) to gain a statistical edge over the casino. Modern wheel manufacturing and maintenance protocols have largely eliminated significant bias, but regular wheel testing and rotation remain critical components of game integrity programs.

In practice

Casinos should conduct periodic statistical analysis of wheel results to detect any emerging bias. Any wheel showing statistically significant deviation from expected distribution should be removed from service immediately for inspection and repair.

One entry from the Casino Industry Glossary — 1,157 terms written for surveillance, compliance and operations professionals rather than for players. Definitions describe industry usage; where a term carries a regulatory meaning, verify against the instrument that governs your jurisdiction.