topherhunt

0 And 1 Are Not Probabilities

What are the

oddsthat the face showing is 1? Well, the prior odds are 1:5 (corresponding to the real number 1/5 = 0.20)

I'm years late to this party, and probably missing something obvious. But I'm confused by Yudkowsky's math here. Wouldn't it be more correct to say that the prior odds of rolling a `1`

are `1:5`

, which corresponds to a probability of **1/6**** **or** **

? If odds of **0.1666...**`1:5`

correspond to a probability of `1/5`

= `0.20`

, that makes me think there are 5 sides to this six-sided die, each side having equal probability.

Put differently: when I think of how to convert odds back into a probability number, the formula my brain settles on is not `P = o / (1 + o)`

as stated above, but rather `P = L / (L + R)`

, if the odds are expressed as `L:R`

. Am I missing something important about common probability practice / jargon here?

I've seen Yudkowsky make this point in a couple places (why bother inflicting mass infanticide etc. etc. when you're presumably omnipotent and could teleport everyone to safety) and it makes me blink, something about the argument feels off. Are there cases in the scriptures where God teleports large numbers of people large distances? I get, and vehemently agree with, the point being made here (you can't deny that in this and many other stories, God had more humane alternatives available, and knowingly opted for a crueler one) but unless there's a clear precedent for mass teleportation, this specific argument seems to strawman the religious belief a little.