tag:blogger.com,1999:blog-2802520424485051490.post1124861483023558007..comments2023-03-30T06:56:31.229-07:00Comments on Fuzzy's Dicecapades: Spinning Down (dice testing)Fuzzy Skinnerhttp://www.blogger.com/profile/10606454596061907461noreply@blogger.comBlogger2125tag:blogger.com,1999:blog-2802520424485051490.post-57891997474602125432018-06-10T08:34:17.620-07:002018-06-10T08:34:17.620-07:00Good point. I also need to try the saltwater test ...Good point. I also need to try the saltwater test on it, and a second rolling test couldn't hurt (as long as it's done on a day when my wrist is in better shape).<br /><br />I remembered hearing about an article in <i>Dragon</i>, but couldn't remember which issue it was; thanks for pointing me to it!Fuzzy Skinnerhttps://www.blogger.com/profile/10606454596061907461noreply@blogger.comtag:blogger.com,1999:blog-2802520424485051490.post-1064062522456606262018-06-09T17:22:07.592-07:002018-06-09T17:22:07.592-07:00If you have access to Dragon Magazine #78 from Oct...If you have access to Dragon Magazine #78 from October of '83 there is an article about testing dice entitled "Be thy die ill-wrought?" which describes how to perform a chi-squared test on a die to decide if it is statistically biased. According to the author you would need at least 100 rolls on a d20, ideally 200, to reliably analyze the fairness of your die.<br /><br />The procedure is to tally the number of times you get each result (as you have) then sum the squares of the difference between that tally and the expected occurrences. With 80 rolls of a d20 you would expect a perfect die to yield each result 4 times. Take the the sum of the squares of each difference (97 in your sample) divide it by the expected value of 4 and compare this to a chi-square confidence table (someone with more background than I have might be able to explain this). Your set yeilds 24.25 which is under the 27.204 required by the test to be reasonably assured the die is fair. The number would have to be over 36.191 to be reasonably sure it is biased. In between you might go again with a larger sample.<br /><br />So, despite the pattern your mind detects, you die appears to be fair. Sterlinghttps://www.blogger.com/profile/08163131298685381872noreply@blogger.com