Glossary · lab
Chi-square test
Statistical test comparing observed hits per pocket with the expected n/37. Used to judge whether a wheel is biased.
In context
Add up (observed − expected)² / expected over 37 pocketsequipmentPocketOne of the 37 numbered compartments on the rotor. Also: slot, cup.Read full →; compare with the chi-square distribution on 36 degrees of freedomlabDegrees of freedomThe number of independent values in a statistic. For a chi-square test on 37 pockets it is 36, because the counts must add up to the total.Read full →.
Did you know
Karl Pearson published the test in 1900, and one of his first worked examples was 26,306 recorded Monte Carlo roulette spins, which he found suspiciously non-random. Later analysis suggested the journalists who recorded them had invented some.