URTH 

From: Michael AndreDriussi <mantis@siriusfiction.com> Subject: (urth) pair o' dice no paradox, men Date: Sat, 15 Dec 2001 07:43:35 0800 Thanks Sunanda! Joel Sieh also caught this and I thought he and I had posted to the list! Here is my quote and response to him. Joel Sieh wrote: >>6 different throws on each of two sided dice gives us 36 possible throws. >> >>Possible combinations equalling 7: >> >>Die 1 Die 2 >>1 6 >>2 5 >>3 4 >>4 3 >>5 2 >>6 1 >> >>Total combinations: 6 >>Probability = combinations equalling 7 / all possible combos >>= 6 / 36 = 1 / 6 = 16.6%. >> >>Following these calculations, rolls of 2 or a 12 would each have a >>probability 1 / 36. I agree that these are much less probable than >>rolling a 7 (the most probable roll with two six sided dice), but it seems >>that 1 / 6 is still against the odds, if you consider "against the odds" >>to mean less than 50%. > >Wow, you are right! > >What was I thinking? > >Well, I was working off the fact that in games involving two dice, 7 is >the middle of the bell curve. I was erroneously thinking in terms of the >odds of rolling >= 7 or <= 7 (which is a 58% probability), rather than >just 7. > >With regard to the text I was also puzzled as to why a 7 would mean death, >when, for example, there are 10 men. Up until the moment I typed it in, I >sort of thought there were only 7 men, and the dice were saying how many >would die (all, in this case); but the dice tell a group fate, not a >fractional amount (all die or none die). On my first reading I thought he >was supposed to roll a number related to the number of crewmen, like, say >>= 8 (42% chance). > >Even as I was typing it in this evening, and there was a glimpse of the >truth (that rolling a 7 really is a 1/6 chance), I veered away from this >and into the notion "Why not just use one die, if oneinsix is the >desired probability  then the roll of a =1= would make the whole thing >quite obvious." And the waste of a perfectly nice bellcurve (as opposed >to the "flat" curve of a single die)! > >(The reason why oneinsix is important is made clear in the text: that is >the fatality rate for sunmen.) > >The reason why a 7 means death is because that is the only way to squeeze >out a 1 in 6 chance out of two dice! > >Anyway, I was wrong. Thanks for correcting me! (I still wonder why >Harness would choose to use =two= dice when one die would work better. >Well, work better for =me=, at least!) > Addendum: we both arrived independently at the notion that Harness is probably talking about the dice game "craps," which, in the prewargaming/prerpg world, was the most common exposure to dice games. =mantis= Sirius Fiction Has Moved To http://www.siriusfiction.com/