Space Review article

Well. Let's see: 30 essential techs, and all must succeed, and if
even one fails, then IT'S ALL OVER. And even if each has a 90%
chance of succeeding, that's only 4% overall.

OK, look, this is, strictly speaking, true. But it's just a number
game. First of all, some things on that list have a much better
chance of success than 90%. Such as # 14: Recruitment of the 10,000
people. Does anybody think that there is only a 90% chance of
finding 10,000 people for the job? Really. And how about # 16:
Invention of the new technologies, equipment and processes required.
But right after that we find # 17: Lunar operations, and # 18: Lunar
prospecting, and so on. Don't both of these (and some of the others,
too) count as "invention of the new technologies, equipment and
processes required"? So some of these 30 essential techs are, in
fact, the *same* techs, only phrased differently. That changes
the 'thirty nineties equals four' equation considerably. Except that
the whole 'thirty nineties equals four' thing is bogus, because
engineering isn't a crap shoot with d10's.

Look at it this way: I have thirty dice. These are ten-sided dice,
of the type used to play such games as Dungeons & Dragons. Except
that, in this case, the dice are not numbered. Nope, they are each
green on nine faces, with the remaining face on each die colored
red. In order to achieve "success," I have to cast them, and get
them all to come up green. Now of course the chance of *any one die*
coming up green is 90%, but the chance that they will *all* come up
green is only 4%. Guess you'd have to be a fool to bet on me, eh?

Ah, but if this game is a little more like engineering, and a little
less like a casino, then I get to do something that would get me
kicked out of Vegas. Suppose that, after casting my thirty dice, I
look at them closely, pick up any that have come up red, and cast
them again. Then I repeat the process again. And again. And
again. How many turns do I have to be allowed before you'd have to
be a fool to bet *against* me? That's how engineering works: you get
to keep trying until you get it right... until you get it ALL right.

Not to mention the fact that I'm loading the dice a little each time
I make a new cast. Messing with the variables (in this case, dice)
in order to bump the odds in your favor is unethical in gambling, in
fact it's cheating. But it's unethical *not* to do exactly that in
engineering. If I'm designing a new roof for a hospital, I'd
*better* try to "load the dice" as much as I can, to make sure that
roof doesn't fall in.

Again, Sam Dinkin's math is good (I assume; I wouldn't be able to
tell if it weren't), but what he does with it is silly. Engineering
isn't a crap shoot played with d10's.

Xenophile (not an engineer, not a mathematician, not a gambler... but
come on)