I looked at a delta-formula, but there is no clear cut way to definedx/dx'from the original formula without using advanced math stuff.

However, if you prefer the rating-way, here's my shot at it:

1/x' = 1/C + k/x with x = rating / A (A = 176.7189 for all plate tanks)

You are looking to know what the rating required is (defined as dr, with rating you have as r) atx' + 1%, so:

[MATH]

1/x' = 1/C + Ak/r => x' = (rC) / (r + AkC)

1/(x' + 1%) = 1/C + Ak/(r+dr)

x' + 1% = [C*(r+dr)] / [(r+dr) + AkC]

adding in the earlier found x'

(rC) / (r + AkC) + 1 = [C*(r+dr)] / [(r+dr) + AkC]

(rC)*[(r+dr) + AkC] + [(r+dr) + AkC]*(r + AkC) = [C*(r+dr)]*(r + AkC)

rēC + rC*dr + AkrCē + (rē + 2* AkrC + r*dr + AkC * dr + AēkēCē) = rēC + rC*dr + AkrCē + AkCē*dr

worked out everything & putting all dr on one side:

rēC + AkrCē + (rē + 2* AkrC + AēkēCē) - rēC - AkrCē = [rC + AkCē - rC - (r + AkC)*dr

(rē + 2* AkrC + AēkēCē) = [AkCē - (r + AkC)]*dr

dr = (r + AkC)ē / [AkCē - (r + AkC)]

dr = (r + AkC)ē / [AkC(C-1) - r]

dr = (r + 11088)ē / (716633 - r)

[/MATH]

Could use some extra eyes checking the numbers, just in case I made a mistake somewhere

I did, but it's fixed now, thanks Booi & jere!

Just double-checked with Maple, Rating need for 1% avoidance =

with R the rating you currently have. (This includes the DR from rating you have yet to gain).Code:(R + 11088)ē ------------- 716633 - R

Also, to find the rating for any n% avoidance gain:

Here are some numbers for the 1% calculation:Code:(R + 11088)ē -------------------------- 11088(65.63144/N - 1) - R

Rating -> rating required for next 1%

1000 -> 204.2

1100 -> 207.6

1200 -> 211.1

1300 -> 214.5

1400 -> 218.0

1500 -> 221.6

1600 -> 225.1

1700 -> 228.7

1800 -> 232.4

1900 -> 236.0

2000 -> 239.7

2100 -> 243.4

2200 -> 247.1

2300 -> 250.9

2400 -> 254.7

2500 -> 258.5

2600 -> 262.4

2700 -> 266.3

2800 -> 270.2

2900 -> 274.1

3000 -> 278.1

At 1481 rating, you are at 80% efficiency or you need toadd 25% more rating to make up for DR.

At 1889 rating, you are at 75% efficiency or you need 33.33% more rating.

At 2341 rating, you are at 70% efficiency or you need 42.87% more rating.

At 2669 rating, you are at 66.67% efficiency or you need50%more rating.

Addendum:

Note, however, that while the absolute numbers decrease, the relative damage reduction makes up for most of it.

At the same 2669 rating and completely no other avoidance, the 265 rating required for 1% extra avoidance still grants >0.76% of the damage reduction it would grant non-DR.

With a 4.4% miss chance and ratings equally divided between Dodge and Parry (for a total of 5338 ratings), you get 88.23% of the reduction it would give at 0 ratings... excluding Block.

So the DR formula provides roughly the same damage reduction per rating, regardless of current raiding tier (assuming you divide them among dodge & parry).

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