Confused about diminishing returns

[spack]

Forgive me on this but I'm so confused about this no matter how much i read i'm getting more and more confused.

When do DR kick in? 21% total between dodge and parry or is it higher than 21%?

[crazymunch]

Dodge and Parry have separate DR. DR Kicks in at fairly low levels of each, but has a very small effect, with the effect increasing as levels of dodge and parry increase.

Have a read of:
http://www.wowwiki.com/Melee_diminishing_returns

Some of the math is outdated, but it gives you a basic idea of how it works

[Needonboots]

Diminishing Returns start happening the minute you get 1 dodge rating or 1 parry rating. They're not a thing that magically happen at a magic number. They're ALWAYS there. 1%-2% avoidance requires less rating than 4-5% avoidance, which requires less rating than 11-12% avoidance, etc.

They're ALWAYS there.

EDIT: Also, Dodge and Parry have the same diminishing returns in Cata now. Try and get Dodge and Parry ratings to the same amount through reforging/gemming (RATINGS, not percentage)

[Nyanmaru]

To give you some numbers:
undiminished dodge = diminished dodge (how much of a % you get % after DR)

5% = 4.93% (0.98%)
10% = 9.35% (0.93%)
15% = 13.31% (0.88%)
20% = 16.90% (0.84%)
25% = 20.16% (0.81%)
30% = 23.14% (0.77%)
35% = 25.86% (0.73%)
40% = 28.37% (0.70%)

To get 5% diminished dodge, you need roughly 5.07% undiminished dodge.
To get 10% diminished dodge, you need roughly 10.79% undiminished dodge.
To get 20% diminished dodge, you need roughly 24.74% undiminished dodge.
To get 40% diminished dodge, you need roughly 70.05% undiminished dodge.
To get 80% diminished dodge, you need roughly 830% undiminished dodge. (this is over the cap, just included for math-fun)

So, to get double the avoidance comparing 5->10 with 10->20 you need 6.2% more dodge rating per % of dodge to double your avoidance. comparing 10->20 to 20->40 the difference is a lot worse since you now need 23% more dodge rating per %. And just to take it to the extreme compaing 20->40 with 40->80 you would need 318% more dodge rating per %.

If you see "Dodge Rating" and calculate "Dodge%" from it, you will get "undiminished dodge".

The forumla for diminished dodge (as stated in the wowwiki article) is this for DKs:
Dd = dimnished dodge, Ud = undiminished dodge
Dd = ( 88.129021 * Ud ) / ((0.956 * 88.129021) + Ud)

Since dodge and parry share the same number, the calculation is the same for both of them.

The % of the two differs because dodge is also gained from agility which has a separate diminishing return (as far as I know).