I was reading a bit about crafting, and want to manually calculate chance to get desired affixes.
Unlucky my result is other than the one form calculator.
Who is wrong?

Link to calculator: http://diablo3.***/spiel/expansion/itemdb/affix_chances_crafted.php?lang=en&version=lod&patch=111&type=belt&item=Light+Belt&sortby=&mlvl=0&qlvl=7&ilvl=21
*** = i n g a m e . d e

For example let's say i want ilvl 21, and this affixes selected:
1) +24% Faster Hit Recovery (Group 18)
2) Replenish Life +3 to +5 (Group 19)

Calculator says:

And that's fine, I agree with this.
But then total chance which it shows is equal to 0.8101346 %. Ekhm?

Now my calculations:
With ilvl 21 i have 18 possible Rare Suffixes and Total Frequency equal 51.
Each of my suffixes have frequency equal 4, so chance to get them are 4/51 = 7,84313725 %
Ok, it's same as from calculator.

But then how to calculate total chance?
I think it should be like this:
We want to get 2 affixes, to we can get fhr first and rl after it, or rl first, and fhr after it.
For rl first we have chance equal to 4/51 and then 4/47 for fhr (we can't pick rl again obviously).
For fhr first we have chance equal to 4/51 and then 4/39 for rl (we can't pick any of affixes in fhr group again).
Total chance should be equal to (4/51)*(4/47)+(4/51)*(4/39) = (4/51)*((4/47)+(4/39)) = 0.0147192538 = ~1,47%

Ok, maybe calculator try to include chance to get 2 suffixes? Doesn't look like it :/
With ilvl 21 we have 20% chance to get 2 affixes, and since this affixes can be prefixes or suffixes, next 25% chance to get 2 suffixes.
It means that chance to to get 2 suffixes with ilvl 21 is equal to (1/4)*(1/5)=1/20

So in our case it would be 1,47192538% / 20 = 0,073596269%

So it's mine 0,0735% (or 1,4719% is calculator doesn't care about chance to roll x affixes) vs calculator's 0.8101%.
Need help :/

plusone

Ok, anyone with brain? ^^

Have you factored in the following:

Magic items have a 50% chance of getting a just suffix, a 25% chance of getting just a prefix, and a 25% chance of getting both.

Damn, you're looking at just crafted.

Leave it with me.

Edit then - I think there is something wrong with your odds for picking 2 suffixes.

The way it will be picked is simply (I think...): All available affixes are pooled as you have done, then pick one. Then we have a 20% chance of picking another. Not sure why you then divide this by 4? For rare and crafted items I don't think they are picked separately, though they will always be restricted to no more than 3 prefixes or suffixes.

This post was edited by AyeCaramba on Nov 11 2009 03:23am

Thanks you for your input
I was based on this:

So with ilvl 21 i have 20% chance of 2 affixes. And since affixes can be suffixes and prefixes, there is 25% chance that both of this 2 affixes will be suffixes.

This is not a 20% chance of two affixes as such.

This is a 60% chance of at least 2 affixes. This is at least one of the reasons you're getting different figures.

Yes, you are 100% right I forgot about this because i need exactly 2 affixes.
Anyway then formula wouldn't be so simple:
20%->2 affixes: they must be 2 suffixes, so its only 25% chance that 2 affixes will be 2 suffixes, so 1/5*1/4 = 1/20
20%->3 affixes: they must be 2 suffixes, so its 37.5% chance that from 3 affixes at least 2 of them will be suffixes, so 1/2*1/4 = 1/8
20%->4 affixes: they must be 2 suffixes, so its 62.5% chance that from 4 affixes at least 2 of them will be suffixes, so 10/16*1/4 = 5/32

So total chance to get at least 2 affixes: 1/20 + 1/8 + 5/32 = 53/160 = 33.12%
And to get correct suffixes is: 0.0147192538 * 0.33125 = 0.00487575282 = 0.48% chance.

Zzzzz :/

:>

Bump