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Liudeath
05-26-2009, 08:47 AM
Ok. We're in Ulduar and having high effective health is just as valued as having high avoidance (which should in turn contribute to EH unless i'm mistaken).

What I want to know, is how would we go about checking a DKs EH? Using the calculator link at the top of the page here The only thing that changes the "EH" column is armor, health, and Block Value. The calculator states that the talent values (the no-duh ones) for paladins, warriors, and druids are added in (respectively of course).

Anyone know the basic formula for Dks EH?

Molohk
05-26-2009, 09:14 AM
Avoidance does not increase your EH. Avoidance lets you avoid (duh) hits, while EH is what keeps you alive when you do get hit. They both work together towards your survivability, but they are different things. EH basically means: "how big a hit you can take without dying".

For physical damage, your EH has two components: health and damage mitigation. Health is pretty straight forward, and mitigation has more variables. For a DK, physical mitigation is affected by talents such as Blade Barrier, Will of the Necropolis, Unbreakable Armor and Bone Shield. For instance, imagine you are a tank with 30k health, 60% mitigation from armor and 5% dmg reduction from blade barrier, that means you can take a physical hit of around 52.6k without dying (because 52.6k * 0.4 * 0.95 = 30k, iirc they are multiplicative) , that's your EH for physical attacks while blade barrier is up.

For magical attacks EH is calculated in a different way, because schools and partial resistances are a factor, but it generally is calculated the same way: by figuring out what's the biggest magical hit you can take. Also, I forgot Frost Presence in my example math, that's an aditional 5%.

Obviously, EH is not static. PW:S, Divine Aegis, Inspiration, Sacred Shield, Gossamer procs, etc. are all factors that change your EH during a battle.

Edit: for overall survivability, some people use a "time-to-live" formula to estimate how much damage you can take before you die, if you do some searching around here there's a thread with lots of info on it.

mandible
05-26-2009, 10:20 AM
First couple things that come to mind.
Frost Presence boosts armour, mitigation and health
Blade Barrier increases mitigation

Frost Presence - Spell - World of Warcraft (http://www.wowhead.com/?spell=48263)
Health would be
1.10 * Health

Armour would be
1.8 * Armour - I think that any items that have above average armour for there ilvl and rings and such do not get to have the multiplier added to them.

5% mitigation from Frost Presence
5% mitigation from Blade Barrier ( which should always be up )

If the DK is frost spec'd he may have Improved Frost Presence
2% more mitigation with 100% uptime.

Unholy has additional passive magic mitigation
Blood generally has additional health through talents.

That should get you started, that's just off the top of my head so that may not all be 100% correct.

Satorri
05-26-2009, 11:22 AM
We're tanking in a rather more intricate world than when EH was first invented. Effective health and Time-to-live are simply methods that attempt to value your survival without having to count on the RNG at all.

In other words, what if my 60% chance to not get hit doesn't fire 3 hits in a row?


Like with everything thee is a balance to recognize. Survival can be generally split into 2 considerations, Avoidance and Mitigation. Avoidance, we know, is miss/dodge/parry, and mitigation is damage reduction from armor, blocks/SD, and absorption mechanics. These two sets of values functionally extend your actual total health value to an "Effective health" value. In that regard you would include avoidance, though many prefer not to because of the random element, whereas armor is always present.

Personally, I don't think there is a tremendous amount to be gained by calculating your EH value, particularly as a DK, but if you want to figure out the value for your own understanding, simply take your max health and reverse engineer with your damage reduction values.

On the big grand statistical average, factoring only passive stats and not including the wealth of damage avoiding tools now available:

EH = [Total health / (1 - miss + dodge + parry)] / (1 - armor) / (1 - static dmg reduction)

So, if your DK has 40k health, 58% miss/dodge/parry, 65% reduction from armor, and Blade Barrier up without imp Frost Pres (10% dmg reduction), your approximate functional health would be:

EH = (40000 / 0.42)/0.35/0.9 = 302,343 health

Without factoring avoidance, it would be:

EH = 40000/0.35/0.90 = 127k

Meaning if you had the worst rolls possible, and the boss was hitting for 40k unmitigated physical damage, you'd be able to take 3 hits without heals and you wouldn't die, but the 4th would kill you.

The EH calculators (TankPoints has one built in if you want to just pick up the addon and use it's version of the fairly arbitrary metric) usually do it more based on weighted values of your raw stats.

Tell me how much a given boss hits for unmitigated and I'll tell you how much I care about my EH. =) All the same it can be a decent way to compare your gear if you trust someone's weighting system.

Molohk
05-26-2009, 11:38 AM
I have to disagree with Satorri because I do not consider Avoidance to be a part of EH. EH and Survivability are not the same thing at all, even though EH is a big factor of Survivability.

The whole point of "effective health" is to measure what's the biggest hit you can take (or more hits without any heals in between) without dying. The concept of EH comes from the fact that tanks can't just look at their max health to figure out what's the biggest hit they can take, because the size of the hit is also affected by other stats and buffs, and that's why theorycrafters came up with the concept of Effective Health which factors in damage mitigation. Avoidance has nothing to do with EH, other than co-contributing (as two independent factors) to survivability.

Satorri
05-26-2009, 12:03 PM
I do not consider Avoidance to be a part of EH. EH and Survivability are not the same thing at all, even though EH is a big factor of Survivability.

The whole point of "effective health" is to measure what's the biggest hit you can take (or more hits without any heals in between) without dying. The concept of EH comes from the fact that tanks can't just look at their max health to figure out what's the biggest hit they can take, because the size of the hit is also affected by other stats and buffs, and that's why theorycrafters came up with the concept of Effective Health which factors in damage mitigation. Avoidance has nothing to do with EH, other than co-contributing (as two independent factors) to survivability.

You have inherent contradictions in your statements.

A.) "Effective health is a measure of the biggest hit you can take, or more hits without any heals in between."

B.) "Avoidance has nothing to do with effective health other than co-contributing to survivability"


Avoidance directly effects the number of swings you can take in a row, and for DK's is arguably the largest factor as we can sport the most avoidance of any tanking class.

Effective health is also only valid for comparing against unmitigated damage from whatever you're tanking, and all you ever see from the game is mitigated damage. The EH you're describing is just moving the armor reduction from the weapon swing to your max health pool which is actually less helpful. Otherwise your total health shows the same thing compared to the mitigated melee swings you see from the game.

So if you don't care to include avoidance in your EH, what do you include? And tell me how your metric is actually helpful and not just an unnecessary abstraction from values the game already tells you?

Molohk
05-26-2009, 12:52 PM
You have inherent contradictions in your statements.

A.) "Effective health is a measure of the biggest hit you can take, or more hits without any heals in between."

B.) "Avoidance has nothing to do with effective health other than co-contributing to survivability"


Avoidance directly effects the number of swings you can take in a row, and for DK's is arguably the largest factor as we can sport the most avoidance of any tanking class.

Effective health is also only valid for comparing against unmitigated damage from whatever you're tanking, and all you ever see from the game is mitigated damage. The EH you're describing is just moving the armor reduction from the weapon swing to your max health pool which is actually less helpful. Otherwise your total health shows the same thing compared to the mitigated melee swings you see from the game.

So if you don't care to include avoidance in your EH, what do you include? And tell me how your metric is actually helpful and not just an unnecessary abstraction from values the game already tells you?

It's no contradiction, by saying "hits you can take" I ment to imply that they were not avoided, hence they were "taken" :P

Perhaps you skipped my post above where I gave a rough example of how I would calculate EH. But given the concept of EH as I understand it, I'd include
any factor that would directly reduce the amount of damage taken by a landed attack, when dealing with physical damage this includes: armor mitigation, percentual damage reduction (frost presence, blade barrier, etc), static damage reduction (shield absorbs and such), and block rating. Obviously, the elements used to calculate EH against magical attacks are different.

The usefulness of EH, as I see it, is only to measure the ability of a tank to survive through big hits (or bursts). Base damage is always mitigated, and the ability to survive any attack (that lands) is a combination of a tank's health and damage mitigation (not avoidance). If you want to call that "an unnecessary abstraction from values the game already tells you" then that's also what your EH formula is, I'm just removing avoidance from the equation.

EH is clearly not a metric intended to be the ultimate tanking stat or to measure overall survivability, time-to-live would be a much better suited metric to measure overall survivability.

Satorri
05-26-2009, 01:47 PM
Mmm, I suppose. Personally, though, I think the desire to discount avoidance as an unreliable survival tool is fairly outmoded. And for DKs it's missing a massive element of our survival since we avoid more than 50% of incoming blows, so long as you are not a poor tank who regularly stands with their back to their targets (and even then, in quick moving we have a tendency to dodge/parry swings that appear to be done while behind us, thanks to latency).

I think, for the sake of the OP and any other curious folks, the thing you need to consider is balancing tanking stats is, as always, a matter of need. Like threat, it's nice if you can do 10k threat, but 6k is sufficient if none of your dps are going above 4k. You only need enough health to reliably take 2 swings in a row without heals (when possible, sometimes it isn't in the hardest of conditions like Plasma Blasts from Mimi or Frozen Blows from Hodir though notice both are magic damage and Plasma can't be avoided), and having stronger avoidance can just ease that damage for the healers.

Take XT as a simple example with only physical beatings. If he's averaging 20k each time he hits you after all your mitigation mechanics, then it is important to have more than 40k total health to ensure you don't get crushed in a heal delay or cast time. Generally speaking, if a boss hits that hard they won't hit faster than every 2 sec and in the time it takes to swing twice (4 sec at worst) there is plenty of time for a big heal cast (2.5 sec at the longest, but healers will have haste even without gearing if you're in a 25-man raid with the most minimal class distribution).

It gets far more complicated as every class has their own mechanics (which we have another thread going on about), and avoidance can make a big difference when one of those swings fails to land which statistically it will, though no one wants to rely on that as you will as surely take 3 hits in a row as you will avoid 3.

Balance can be terribly valuable, in the (unattainable) situation where you undervalue avoidance next to stacking armor and health, you could have say 50k health and 70% reduction from armor but 15% avoidance, and against XT it will be statistically likely that you will take 7-8 swings in a row without respite of a miss/dodge/parry, even though you may take 5-10% less damage per swing (in the above example saving you 3-4k dmg per hit). Every component has its value, though thankfully these days it's hard to screw it up unless you're blatantly ignoring game mechanics (like stacking spellpower on a DK).

Molohk
05-26-2009, 02:35 PM
Please note that I never claimed EH was a super-useful metric, I'm aware it has it's shortcommings. Like you said, 2 unavoided hits back-to-back are likely to happen, that which is a 20k hit for one tank might be an 18k hit on another, I guess that's when it could be valuable to think in terms of EH vs Unmitigated Damage.

When it comes to EH vs Avoidance, I definitely agree that you can't undervalue either one, and their comparative values vary upon the encounter. The thing with EH is that you can't really "stack" armor and other mitigation effects so when ppl talk about stacking EH they mostly refer to stacking stamina (maybe block, but that's not really reliable EH unless you are unhittable), and stacking stamina certainly helps you survive big hits but it doesn't make your healer's jobs any easier, it's avoidance that saves your healers from having a nervous breakdown or going oom in 1 minute.

BTW, what's this EH calculator that the OP mentioned? I can't seem to find the link.

GravityDK
06-09-2009, 04:26 AM
Top of tankspot is this (http://www.tankspot.com/index.php?pageid=Calculator)calculator link.

By the way, I've written a user guide (http://pwnwear.com/tankpoints-user-guide/) on TankPoints that is useful for those unfamiliar with it.

jere
06-09-2009, 12:47 PM
EH as a coined term does not include avoidance at all. I think there is a different term when you take EH and incorporate avoidance. Was it total damage reduction or average damage reduction? I am sure Satrina or Cider knows offhand.

EDIT:
Ahh, GravityDK's link had it. Total Damage Reduction is the measure that also includes avoidance.

The idea behind EH was simply how much damage you could survive without heals, avoidance, or (if you are not a pally or pre WotLK warrior) block before you die...kind of a worst case scenario. Some interpret it as a single hit, and some interpret it as the total amount of unmitigated damage (which is what the equation of Health*EH_Ratio gives you honestly), but in both scenarios neither healing nor avoidance were accounted for (and not block by most).

Molohk
06-09-2009, 12:53 PM
Yeah, that's what Satrina calls "time-to-live" in some threads, which can be considered a measure of "survivability" by calculating how long you can survive a constant ammount of incomming dps without any heals. It could probably incorporate self-heals to be more reliable though (mostly thinking of Blood DKs) but that isn't too easy to calculate since it depends on rotations skill usage.

Satorri
06-09-2009, 02:33 PM
Gravity! Long time no troll!

Effective Health and Time-to-live were coined terms for popular theories/methods in BC. They did not factor avoidance, which was a black sheep more so at the time than now, and as Molohk and others said previously, to gauge the damage you could survive if the RNG failed you completely.

If you want to keep it to the original designs you'd have to discount self-heals since they ARE case specific to the tank, require the tank to do something, and are not fixed. I also think the classic metrics are a bit limited in significance, particularly now that tanks sport higher avoidance, more consistently, for all class/specs than they used to.