How good is Armor really?
I got a drop that was a hard choice for me. both these items will be replaced when I get some more valor badges but it spawned an interesting set a math.
A) Durable Nerubhide Cape - Item - World of Warcraft I have
B) Cloak of Armed Strife - Item - World of Warcraft that dropped.
differences in stats when I replace my old A) with b)
49 dodge rating
21 expertise rating
37 def rating
28 hit rating
also a little bit of a prelude, I am at the def cap just barely 540. (almost all purples (The World of Warcraft Armory) feel free to look me up).
So I first looked at the avoidance aspect. using the avoidance macro that was placed on this site a couple weeks back, due to diminishing returns and the fact that my old cape had 0 def on it, my TOTAL avoidance drops 0.31% (but is more spread out over parry/dodge/miss).
But what do I get to compensate for this 336 armor. To see how much that helps I calculated my effective health (including the drop in stam).
69559 vs 69512 so barely any change there.
But what is the pros and cons here.
I will be 41 rating over the cap, so I only have 1-2 gems that have 8 def on them, which I can then replace to make much the health loss. but that will then increase the avoidance loss by a bit more.
but assume I keep everything the exact same just swap out the cloak.
over the course of 1000 hits. The numbers on the left side are the amount of damage hit, middle is the amount of damage saved if 0.31 % avoidance was used. and the right side is the extra 336 armor that was added (not including multipliers)
10000 31000 34807
12000 37200 41768
14000 43400 48730
16000 49600 55691
18000 55800 62653
20000 62000 69614
22000 68200 76575
24000 74400 83537
26000 80600 90498
28000 86800 97459
As you can see if nothing else changes the over all damage would be reduced if I equip the armor cloak. the other point of interest is the hit vs expertise and I would be sad to see the expertise loss but I am not hit caped yet so I think this is a minor point but I could be wrong.
I know this cloak will not last me for very long but I thought it would be interesting to see in this specific example what peoples thoughts would be ?
Armor is really good against physical damage. In these days of tanking dragon breaths I'd stay with the one with more stamina.
I go by the rule of thumb that 400-500 armor ~= 1% damage reduction. (Try it. Put on something with this amount of armor and check the tooltip. Take the difference in damage taken and divide by total damage taken. Example, previous DR is 60.5%, new DR is 60.9%, 0.4/39.5 = 0.01.)
So compare this 1% EH increase to a 1% EH increase via stam--if you have 30k life, 300 life would be the equivalent, which is ~27 stam.
Just remember that armor is strictly worse than HP (until/if healers have mana issues again) because it doesn't work against magic.
Comparing it against 1% avoidance, of course, depends on the fight.
If I am looking at comparing health and AC, the equation I use to figure this out typically comes from the basic EH equation
Extra_Health*(AC + 16635) = Extra_AC*Health
400 more AC (I am at 26000 AC and 39000 HP typically in raids):
Extra_Health*(26000+16635) = 400*39000
Extra_Health = 365.9 Health
So 400 AC is worth the same as 365.9 health for me in terms of the amount of EH added.
25 stamina for me would actually be 25*1.1*1.08*1.06 = 31.5 Stamina for me given talents and BoK
So the AC would beat the extra hitpoints by on the order of 55 health. However, since they are so close, I would go for stamina for magic fights, etc.