I recorded 78 d20 rolls as I was playing the game normally, then I gave up. =P (Keeping track of combat rolls is too annoying; you have to hover over everything in the combat log, some rolls can't be recorded because they don't show up at all, and you need to disregard advantaged/disadvantaged rolls, 'cuz those only report the final result.) My average roll came up to be 9.2, which seems reasonably average for that sample size.
When it comes to determining if 20 happens as often as it should, correct me if I'm wrong, but wouldn't that require a pretty monstrous sample size? E.g. if we decide 200 rolls is an ok sample size for determining if the rolls are skewed one way or the other, wouldn't it require 20 times that many, i.e. 4000 rolls?
