Shifting Perspectives: Why effective health needs to die, part 1

If you've tanked at all over the course of Wrath, you've probably become familiar with the phrase "effective health." It's a concept that's cropped up with increasing frequency on the tanking forums, and not necessarily in a good way. If you knew nothing of the idea beyond how players tend to use it, you'd be forgiven for thinking that "effective health" is the only metric by which all tanks are measured, and proof that Blizzard either can't (or won't) balance the game. There are very real differences between the tanking classes when it comes to average EH, and this has resulted in some angry discussion when the term is thrown around by players who either don't really understand what it means, or don't know that it was meant to be used in context. Consequently, "effective health" as used on the tanking forums has become an endlessly parroted phrase that's not only starting to lose all meaning, but is also guaranteed to derail a thread once it makes its inevitable appearance.
When I say that effective health needs to die, I don't mean that the concept itself is intrinsically wrong. It's not. But the twisted version of it so frequently used to bludgeon players over class differences is getting more ridiculous by the day, and it prevents or distorts more reasonable commentary on things that are much more likely to kill tanks on hard-mode content.
Why effective health is important
Effective health was a concept first discussed by Ciderhelm of TankSpot in a May 2007 article when pre-nerf Karazhan was progression content. It was something he'd toyed with since tanking the original 40-man Naxxramas, and more particularly Patchwerk, when it became obvious that the off-tanks had to reach a certain armor and stamina threshold to avoid being one-shot by Hateful Strike. Under those circumstances, he observed, it was pointless to encourage a tank to stack avoidance; when they inevitably failed to dodge or parry a Hateful Strike, they still had to survive eating the blow. A raid that wanted to get past Patchwerk had to be realistic about the amount of damage the offtanks were likely to absorb from a Hateful Strike and gear them accordingly.
The general principle is simple; tanks, regardless of how high their avoidance is, will eventually get hit. Ideally, you want that hit to be as small a percentage of the tank's life as possible, because healing a tank through a blow that hits for 15% of his/her life is much easier than healing through a blow that hits for 40%. Because most other contributions to tank survivability are procs (e.g. Ancestral Fortitude) or RNG (avoidance), the only way to ensure that an incoming blow will always hit for less is to gear for as much armor and stamina as possible. More armor reduces the damage of the blow; more stamina guarantees that what does land will be a smaller percentage of the tank's overall health. Good tanking is about avoiding damage, but it's also about being able to smooth incoming damage into a manageable rate for the heal team.
Isn't that basically the druid tanking model?
Yes -- to a certain point. The BC-era druid tank was essentially a waddling pile of effective health, because we were designed around the ability to mitigate (rather than avoid) crushing blows. With a 15% chance per hit to receive a 150% damage attack with no way to dodge it, druids stacked armor and stamina to turn monstrous hits into manageable ones. Warriors and paladins were hit less often and could avoid almost all crushing blows, but the hits they did take were proportionately larger than the ones that fell on a druid. Over the course of a given encounter, the druid would take more cumulative damage but less per hit; warriors and paladins would take less cumulative damage but more per hit.
Although it made us overpowered versus basic melee damage, the druid's armor and health advantages were not considered a significant balance problem. The need to absorb crushing blows, our vulnerability to magic damage, our lack of worthwhile cooldowns, and inconsistent itemization all made the druid a less attractive choice than we might otherwise have been. However, it was the inability to deal with mechanics like Pyroblast (Kael'thas), Shear (Illidan), Deaden (Reliquary of Souls), and Fear (Nightbane, Archimonde) that made these encounters virtually impossible for a druid to main-tank.
To put it very simply, the druid's effective health advantage didn't make much difference on encounters where tank death was overwhelmingly the result of mechanics that ignored armor and health. Thus, the ultimate lesson of the BC tank experience is that encounter design is capable of bypassing a particular tank's strengths, regardless of how massive their advantage is -- and the druid's armor and health, relative to a plate tank's, were considerably higher than they are today.
What happened when crushing blows were removed from the game?
This is an issue we've discussed previously, so I won't repeat it at length here, but Shifting Perspectives: Tanks, Wrath, and crushing blows illustrates the transition between Burning Crusade and early Wrath tanking. As a gloss on that March 2009 article, the introduction of the death knight tank forced Blizzard to eliminate crushing blows from boss' hit tables, as PvE and PvP balance problems would have resulted from a 2H-weapon tank being able to avoid or absorb them. However, death knights still became the progression tank of choice on hard modes, mostly due to the introduction of giant magic-based hits and cooldown-based tanking in general (e.g. Sartharion 3D, hard-mode Vezax), which was uniquely suited to the death knight's ability to chain strong defensive cooldowns with help from a 25-man heal team.
In another nod to the influence of encounter design, warriors and paladins -- by no means weak tanks, but still designed around avoiding the now-obsolete crushing blow -- were hit hardest by the introduction of "crushing blows" that ignored their avoidance, +block, and armor. Druids, by contrast, were an acceptable second choice if you didn't have a death knight; having been designed around swallowing melee crushing blows gave us the option of stacking stamina in order to absorb the magic "crushing blow." While the druid was significantly harder to heal than the death knight on content that made use of this damage, a large health buffer provided a welcome margin for healer error.
Now and then
Roughly 8 months after writing that article, several things have changed:
- Death knights have been nerfed, mostly in the form of their ability to chain percentage-based damage reduction cooldowns. Right now they are popularly considered the weakest tank for progression raiding, although (as always) much of the community discussion concerning this is completely overblown.
- Paladins have been buffed, most notably in the form of the new Ardent Defender. In an interesting reversal of their usual fortunes, they are popularly considered the best tank for progression raiding.
- Warriors are roughly the same, although Glyph of Shield Wall (introduced in patch 3.1) has given them the opportunity to tailor Shield Wall to specific encounters, particularly in conjunction with Improved Disciplines.
- Druids have been nerfed, but are still popularly considered the second-best or best tank for progression raiding due to an effective health advantage (should they choose to stack stamina over avoidance, and most do). In another curious note, especially given the tanking community's strong feelings on the matter, druids have also been confirmed to be the least popular raid tank.
Every week, Shifting Perspectives treks across Azeroth in pursuit of truth, beauty, and insight concerning the druid class. Sometimes it finds the latter, or something good enough for government work. Whether you're a Bear, Cat, Moonkin, Tree, or -- for some unaccountable reason -- stuck in caster form, we've got the skinny on druid changes in patch 3.3, a close look at the disappearance of the bear tank, and thoughts on why you should be playing the class (or why not).Filed under: Druid, Analysis / Opinion, (Druid) Shifting Perspectives, Features, Raiding






Reader Comments (Page 1 of 4)
Gamer am I Nov 19th 2009 9:10AM
I'm sorry if you answered this question in your article, but as a raiding newbie, I need to ask; what, exactly, is effective health?
andy Nov 19th 2009 9:25AM
i will use a really simple example
say you have 20k health, and you have enough armour to take 50% less damage so you effectively have 40K health,
mark me down if im wrong but i thank im right?
Zinn Nov 19th 2009 9:44AM
At Tankspot they describe it as;
"Effective Health is the measurement of how much breathing room your healers have to keep you alive assuming all other factors fail -- assuming you do not avoid or block attacks or have a mana shield active. Effective Health is important for tanking heavy hitting creatures because of Murphy's Law -- if you can have long strings of not Dodging an attack, it will definitely happen. Raid tanking, ultimately, is about stability."
I found the info on some weird cached tankspot-page so I recommend you just google "What is effective health" or sumthin like it if you wanna know more.
Druidski Nov 19th 2009 9:50AM
I was under the impression from the article that "effective health" = a baseline effective health you would need to survive an attack sans avoidance. For example; if a boss can strike you for 25k (armor mitigated) and your health pool is 24k, all the avoidance in the world would not help you if your health could not sustain that attack. The idea is there is an effective health you need to have to survive when a strike eventually does get through.
Maybe I'm not getting it, seems to be a common thread in the community as Allison pointed out.
Heilig Nov 19th 2009 11:11AM
Actually, the effective health number is calculated BEFORE any mitigation. Bosses hit for massive amounts before mitigation, just ask clothies. Blizzard has to take mitigation into account when they determine how hard a boss' "raw" hit damage is. Effective health is how much "raw" damage you can take without heals before you die.
For example: If a boss hits for 50K before any mitigation (a not uncommonly high number at all) and you have enough armor to mitigate 60% of the damage, then each hit will land for 20K. If you have 40K health, then you can absorb 2 of those hits before you die. That means your "effective" health is two "raw" boss hits, or 100K. Avoidance and cooldowns are not factored into this equation, which is a major problem. High avoidance and a little luck can extend the life of a tank indefinitely, and Blizzard at least recognizes this, which is why so many encounters have unavoidable spike damage, which is why cooldowns are so important.
DK's at first were the best tanks for progression not because of high effective health levels, but because they could reduce even unavoidable damage to acceptable levels without any outside assistance. Being able to reduce three successive buffed fire breaths on 3D without having to ask for a guardian spirit prevented most other tanks from even being considered for tanking that encounter.
In short, Effective Health is a nice metric for determining how many physical hits a tank can eat before he dies, but has little bearing on the reality of tanking due to cooldowns and avoidance. Blizzard recognizes this, as do most of the best tanks and tank theorycrafters, but the vast majority of tanks and forum-dwellers don't understand this and simply cite effective health levels as reasons for tank buffs or nerfs, without even taking encounter mechanics into account.
LilBanshee Nov 19th 2009 11:44AM
Your effective health is the number of unmitigated points of damage it would take to drop you from full health to death. At the simplest level that is just based on your health pool and the percentage damage reduction you get from your armor. See this article for some specifics on how that works: http://www.wow.com/2009/09/13/1-local-in-which-he-man-and-eddie-get-pwned/
Effective health is not a constant for a given tank, though. If you pop a cooldown that reduces all incoming damage by 50%, that temporarily doubles your effective health. If you count guaranteed shield blocks from a paladin, your effective health becomes variable based on the number of blocks you would get in (usually 1-3) before dying from full health. The big debate is how to compare effective health between tanks with different kinds of cooldowns. Some people prefer not to count cooldowns at all unless they can be sustained 100% of the time.
Delmonico Nov 19th 2009 12:14PM
Tankingtips.com, run by Vene who is a frequent contributor to Tankspot, has an effective health calculator on the site.
As an example, my EH with 37000 hp and 24500 armor against a level 83 (Raid) boss is 91,949.
LilBanshee Nov 19th 2009 12:32PM
That's a nice calculator - although its important not to convince yourself that your health pool and armor are the only factors in effective health. For example, if you tank with a shaman or a priest healing you and they get a crit at least once every 15 seconds, you get a flat 10% reduced incoming damage which works out to an 11% boost in effective health. If you ignore critical details like that, your effective health calculation will be meaningless.
Anything that reduces incoming damage boosts your effective health. You have to take into account talents, self-buffs, buffs from your raid, and (as mentioned above) procs like inspiration/ancestral fortitude if they stay up enough.
OneMHz Nov 19th 2009 2:30PM
I think it's funny in an article about how confusing and misunderstood "Effective Health" is, that the first block of comments is a bunch of very different definitions for it.
Turtlehead Nov 21st 2009 3:27PM
In an article about people misunderstanding and misusing a term it'd be awfully helpful for an explicit definition before the history lesson.
robthegraham Nov 19th 2009 9:12AM
My warr tank is no longer taken on toc raids, complaints that my health is to low in compairison to the other classes, even though my block, armor, def rating, and other such stats are compairible.
Adeany Nov 19th 2009 9:25AM
If I was choosing between two tanks with comparable block, armor, and defense rating, why would I pick the one with less HP?
Royal Nov 19th 2009 9:27AM
Guess those raiders will have a hard time ever doing ToGC Anub without a block tank on adds but yea some RL clearly don't read or try to understand the mechanics of an encounter.
Gnosh Nov 19th 2009 9:29AM
For precisely the thing that all these models and simulations don't account for.
PLAYER SKILL.
I'll take a reliable, slightly undergeared Death Knight over an unskilled paladin any day.
(Healer permitting)
Grak Nov 19th 2009 9:32AM
The reason is probably because there is alot of magic based damaged in ToC, which armour, block, etc. has not effect on reducing, and you just have to take the damage right in face, which more stamina helps with.
Karilyn Nov 19th 2009 9:34AM
*sigh* What is your unbuffed health?
Last person I saw complaining that people wouldn't take him to ToC10, and how unfair everyone was, and how people are big jerks for judging him based on his gear instead of his skill...
Had 25k HP unbuffed.
That guy pissed me off so much. I started Naxx with 28k HP unbuffed, back in December, before we had all these fancy new bracer enchants, epic gems, and conquest badges from heroics. I started ToC with around 36k HP unbuffed.
And it seems more often than not, when someone is complaining about people not giving them a chance, it's because they are horribly undergeared, and have no comprehension of their own limitations. So let me ask you... are you horribly undergeared and have no comprehension of your limitations?
N-train Nov 19th 2009 10:57AM
@Grak
You're is actually kind of right. Half the reason EH has become so popular is the last two raids (ToTC especially) have thrown out a lot of mechanics that avoidance can't save you from, and that is no fault of the players and all of the design team. It's so much purely magic damage as it is unavoidable damage, like Gormak's impales or a Jaraxxus fireball or a Twin's orb or Anub's frozen slash. Sadly no amount of avoidance, even if stacked correctly, can dodge Anub's frozen slash, and so a tank needs enough EH to be able to take that without dying.
I don't like it, at all, but its not really the tanks fault, and my guild does TotGC with a warrior/DK tanks and we have no problems.
And remember, the point of avoidance is (in most normal fights) to avoid not every hit, but to avoid a string of hits, which is often the main reason for a tank going down. The more avoidance you have, the higher the chance you won't get hit TWICE in a row, and even less so three times in a row, and even less so four times in a row.
LilBanshee Nov 19th 2009 12:17PM
@Grak
It's important to note that magic damage doesn't throw effective health out the window and make it strictly about stamina. Magic damage just changes the still-complex calculation used to determine effective health. A tank might have 50,000 health, but that's not his effective health even against magic attacks. Take my paladin for example, and assuming I actually had that much health to start with....
TALENT: Improved Righteous Fury: all damage taken is reduced by 6% . . . Now my effective health is 53191
BUFF: Blessing of Sanctuary: Reduces damage taken from all sources by 3% . . . Now my effective health is 54837
TALENT: Argent defender: all damage taken below 35% health is reduced by 20% (works out to a flat 8.75% increase in effective health) . . . Now my effective health is 59635
TALENT: Shield of the Templar: Reduces all damage taken by 3% . . . Now my effective health is 61479
I won't even go into the effects of divine protection, because that's just begging for an argument about what should and shouldn't count towards effective health
Other classes have different sets of talents and buffs unique to themselves. I've seen DK tanks that have two separate tanking specs, just because unholy has more magic mitigation so they switch to it for that kind of boss, then back for physical bosses.
John Nov 19th 2009 9:52AM
As a healer, I can say crushing blows with that name may have been removed from the game, but they snuck right back in as Blizz realized tanks were just not getting hit and (according to Blizz) healers need to be challenged because healing is so easy.
And now the only classes/specs who can heal main tanks are paladins and (some) disc priests [for progression, not for fights the MT/OT and healers outgear of course] because anyone else's big heals are just not mana-efficient enough or big enough.
theRaptor Nov 19th 2009 12:04PM
What do you mean by "progression"? Heroic modes?
My guild cleared 5/5 TotC-25 and 4/5 TotGC-10 without a single Paladin or Disc priest. Considering we had only managed to kill Hodir in Ulduar we definitely weren't over geared.