This is a discussion on About rebirth system !!! within the General Chat forums, part of the Knight Online (ko4life.com) category; Originally Posted by MushtMan
if u havent taken a probability course, don't go posted like u know it all.
anyways, here's a post i found i wrote ages ago:
Last edited by MushtMan; 04-21-2011 at 01:28 AM.
So the chance of success increases as the level of the weapon increases?
Are you sure that's right?
I think you've worked out the chance of failure...
If it was 88% chance at +11 rebirth there would be a hell of a lot of +21's around.
It's been a while since I did probability but i'd say it sounds more reasonable if you did 1- your success rates.
so +11 rebirth would be roughly 0.12% each uprgrade.
- +9 to +10 AKA +11 rev to +21 rev is 1%
To upgrade from +11 rev to +21 rev you need 10 upgrades.
The percent to upgrade each rev will be 1% split 10 ways, in other words 0.01^0.1 = 63% each rev upgrade.
I'm not gonna go into the tears percentage cus to me tears sounds like bullshit, i don't think it adds 30%.
Anyways each rev upgrade would be 63% chance, but to get from 9 to 10 it would multiply to 1% chance.
Like Mush said, in order to get an item to +21reb you need to sucess 10 upgrades.
11->12 AND 12->13 AND... AND 20-<21 and if you notice,
0,8894*0,8894*0,8894... (ten times) = 0,8894^10 = 30,97% this is the probability of making a +11reb item to +21reb item if you use tears all the way. remove tears and you get 0,97% chance of sucess.
Thats why there is not alot +10, going all the way is not 88%, its 31%.
You dont have to divide anything in that, just solve the equation for X.
X= probability of sucess from one step. We need to find it. We know we need 4 upgrades to make is +5reb.
we know that the total result (+1 to +5reb) = +7 to +8 (from website), but since we need 4 upgrades, we have
X*X*X*X = P(+7 to +8) ------> probability to make +7 to +8 = 0,05
X*X*X*X = 0,05 now solve for X
X^(1/4) = 0,05 or 4th square root of X
then X=0,4729 (almost 50% lol) that is without tears
add a tears and we have 0,4729+0,3 = 0,7729
Thats is the right calcul, you need to add the tears at the end (the 0,3) not in beginning like in my 1st page, little error but dont change alot, i'll edit in a sec
I wanna go get a math course then read this topic
I'm sure your math is correct, but let's consider the assumptions.
"when K2 implemented the rebirth system, it was written on website that the total probability is exactlly the same"
did you mean the mgames developers or K2? If K2, I wouldn't have any confidence in what they say. If mgames, it may be their intention to be exactly the same, but maybe their code has errors which does not produce "exactly the same" results
All of the private servers out there and no one has done massive tests / upgrades to document results?
But why have you so a good luck for make a shard rev +9 to +13 rev and +11rev to +12rev
normal have you 90% cahnge on burns
Even if it was 99% chance of success, you could still burn 50 in a row, even 100 in a row. Its called probability, the end number of upgrades is endless, could be 1 million burns and 99 million ugrades. Could be 1 burn, 99 upgrades, could be any ratio.
So according to your maths, the higher + you go, the higher the chance it succeeds! GG