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How to check your upgrade chances using Binomial Probability Calculator.

Discussion in 'Archive 2.0' started by DapperBae, Nov 15, 2019.

  1. BaeSir

    BaeSir User

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    Hello,

    Here is a guide to calculate the odds for your upgrades using the Binomial Probablity Calculator.
    This will help you to plan how much L-coins you have to spend roughly in order to get a certain item.
    For example: Dragon Belt +5

    Basically if an item has 50% chance of success for upgrade,
    It doesn't mean that if you upgrade 2 items then the success rate will be 50%+50%.
    It is actually 75%.

    How it works:

    The calculator tool can be found here.
    https://stattrek.com/online-calculator/binomial.aspx

    See the below for picture examples and explanations:

    There are 3 values you need to fill in for the calculation.

    1:
    "Probability of success on a single trial"
    This is the success rate of the upgrade.
    You can find the most of the percentages here: https://eu.4gameforum.com/threads/667451/

    For weapons, the odds is always 70%
    So the odds of upgrading a weapon from +4 to +6 is 0.7 x 0.7 = 0.49
    This means that, if you have 1 weapon,
    the odds of you getting it from +4 to +6 is 0.49 or 49%
    from +6 to +10 is 0.7 x 0.7 x 0.7 x 0.7 = or 0.7^4 = 0.2401

    For Talisman of Aden
    From +0 to +5 is 1 x 0.8 x 0.7 x 0.6 x 0.4 = 0.1344
    This means that, if you have 1 Talisman of Aden, the odds of you getting it from +0 to +5 is 0.1344 or 13.44%

    2. "Number of trials"
    The number of the same items you are going to upgrade.

    3. "Number of success"
    Usually you put the value 1 here. Then the value of x will be 1.

    Cumulative probability:
    P(X > x)
    This means the probablity of having more or equal number of success than the x value, which is 1.
    Basically, this shows how likely you are to get 1 or more than 1 successes based on the enchanting rate and the amount of items you are going to enchant.

    Binomial probability:
    P(X = x)
    This is the probablity that you have exactly 1 successful upgrade.




    See the 2 examples below:

    - Here i am upgrading something that has 50% chance of succeeding.
    - I have 2 of the items i am going to upgrade.

    Then my chance of getting exactly 1 success upgrade (Binomial probability:
    P(X = x)) is 50%

    My chance of getting 1 or more success upgrade (Cumulative probability:
    P(X > x)) is 75%

    Maiyuan1.png

    example 2:

    I am upgrading Dragon belt from +0 to +5.
    - my chance of success is 0.6 x 0.5 x 0.4 x 0.35 x 0.3 = 0.0126
    - I have 8000 l-coins and buy 20 belts.
    - I want see the odds of atleast 1 of them being upgraded to +5

    Then my chance of getting exactly 1 success upgrade (Binomial probability:
    P(X = x)) is 19.8%

    My chance of getting 1 or more success upgrade (Cumulative probability:
    P(X > x)) is 22.39%

    Maiyuan2.png

    Play with the numbers yourself and see how much money you have to spend roughly to get the desired item you want.

    Good luck!
     
  2. BaeSir

    BaeSir User

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  3. IplayPVE

    IplayPVE User

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    This is nice tool
     
  4. MegiddoFlame

    MegiddoFlame User

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    Wow, nice !!
     
  5. BaeSir

    BaeSir User

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    Bump for visibility :)

    I hope this thread can get more attention that the other thread where people are flaming eachother. Especially when the fundamental theory that is used to calculate the chance of enchanting multiple items is flawed.

    When you are enchanting 1 item, the chance of success can be multiplied together.
    For example when you want to enchant weapon form +4 to +6. This is 2 unsafe enchants, therefore the chance of getting +6 is 70% * 70% = 49%. Assuming the rate of success is 70%. Is like tossing 1 dice 2 times in a row. what are the chances of getting 6 on both times?

    But when you are enchanting 2 or more items and you want to know what the odds of getting Atleast 1 success. This becomes a whole new subject in mathematics.
    Because even if the chance of success is 70%, sometimes you might even break 4 different weapons on first enchant (like i have :D)

    To calculate more specific odds when you are enchanting more than 1 items, this is what they call the Binomial Probability in mathematics. I encourage you to look up for the explanation in your language if you are interested.

     
    Last edited: Nov 25, 2019