Chi square test

[Casinoking1]

Hey,


What does chi square test mean???

[esoito]

Welcome to the forum.  

A good question!

There's nothing in the Maths Reference yet.

I'm sure it won't be too long before someone posts a reply.

There's a lot of information 'out there' on the net  but it's mostly written for mathematicians or those with a strong maths background.

The challenge is to post here a simplified, easy-to-understand explanation for non-mathematicians!

[albalaha]

Pearson's chi-square (χ2) test is the best-known of several chi-square tests ââ,¬â€œ statistical procedures whose results are evaluated by reference to the chi-square distribution. Its properties were first investigated by Karl Pearson. In contexts where it is important to make a distinction between the test statistic and its distribution, names similar to Pearson Χ-squared test or statistic are used.

It tests a null hypothesis stating that the frequency distribution of certain events observed in a sample is consistent with a particular theoretical distribution. The events considered must be mutually exclusive and have total probability 1. A common case for this is where the events each cover an outcome of a categorical variable. A simple example is the hypothesis that an ordinary six-sided die is "fair", i.e., all six outcomes are equally likely to occur or in a roulette whether all 37/38 numbers are equally likely to appear or not.

[Bayes]

A little less technical description is that it's a test which tells you whether your observed data deviates from what's expected, and by how much, so it has a similar function to standard deviation in that regard. If you wanted to find out whether a wheel was biased, you could either calculate the standard deviation of each number or do a chi-square test. I believe the test is built in to the RX software. 

I have a pdf which gives a nice explanation of how to use it (attached). It was written for horse-racing but could easily be adapted for roulette systems.

[esoito]

Well done, Bayes.

Your explanation was the simple one we all needed.

It takes a rare skill to convert a complicated procedure into easy-to-understand language.