So, I did a little number crunching about 2.3...

Here's some real world stuff I'll add from our Gruul attempts.

We tried 4 tanks, 3 Warriors (A, B, C) and a Paladin (P).

Tank A and B were/are bettered geared than Tank C and P. I won't look at the average hit because the tanks that lived longer had larger average hits simply because of the mechanic of the fight.

This is a quote from our guild forum:

Joana is 100% right. The example given of a string of incoming hits, and avoidance allowing that string to be extended is exactly the correct analogy.

The example makes intuitive sense. It also makes perfect mathematical sense. What Joana is essentially given an example of is a small sub-sequence of hits and misses. eg. 7 hits/1 miss. Again, using a binomial distribution for avoidance, you can assign a probability to 7 hits in 8 attempts.

65% avoidance: .36%
50% avoidance: 3.5%
40% avoidance: 10%

In a sequence of 150 hits, you can expect 7/8 hits this many times:

65% avoidance: .52 times
50% avoidance: 5 times
40% avoidance: 15 times

Aha! So, a tank sporting 65% avoidance will see 7/8 hits land every other time he tanks the encounter, whereass a tank sporting 50% avoidance will see 7/8 hits land 5 times during one encounter. If 7/8 hits will kill the tank, a bit over 65% avoidance should be the target.

EDF does not prevent a single string of consecutive hits. What it does prevent is a HEAVY DAMAGE SEQUENCE of many hits(7) and few misses(1) that OVERWHELM the healers ability to compensate.

EH prevents dying in heavy damage sequences, EDF prevents heavy damage sequences from occurring. Let's say in the case above that the tank can choose between 65% avoidance, and dying in 7/8 hits or 62% avoidance, and dying in 8/9 hits (by stacking EH). In this case, the latter configuration is better, it gives a slightly lower chance (40%) that the killing seuqnce of 8/9 will occur during a 150 hit encounter.

_That_ is the line that tanks must walk. EH must first prevent spike damage, such as that which may be taken within 3-4 seconds. After that, EDF and EH must be balanced, such that the maximum heavy damage sequence(which changes based on EH) has the lowest probability of occuring(changes based on EDF).

To put it another way, The worse case scenario that EH is supposed to handle changes its probability of occuring basedon EDF. The ideal will minimize the chance of this occurring.
-Cordelia
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Uhm, what a lot of people seem to be forgetting is that very few bosses / boss encounters involve only melee (ie avoidable) damage.

Very few tanks probably die to "a string of hits". It is more realistic to view it as 2 hits and a failed resist to a bosses special magical attack, imo.

This is definitely one of the best threads I have seen on this forum, and I think I have read 90% of them.

Speaking from a pure-gut sense, I generally agree with the concept of balance and I think that pure stacking of stamina leads to situations where you are like a druid at the armor cap with high stamina. You have tons of HP and are unlikely to die to spike damage, but you are a bitch to heal because you require constant healing.

The random chance for the tank to insert a dodge or parry or miss into an attack sequence can be understood in a slightly simpler way. Essentially, I would say it is required to occassionally avoid an attack. WoW tanks do not seem designed to take consecutive hits. Tank versus boss encounters are supposed to be littered with periodic avoidance. It is all a function of time (including healer cast time). The sad thing is not so much that you cannot predict how often you can get random dodge (that is essentially the percentage anyways), but when. You could get all your dodges at the start of the fight and the end, but none in the middle, etc. While I generally side with EH, I do think EH is flawed as a function of time. You HAVE to avoid some attacks. Think of it this way. Define the attack sequence as the time between avoided attacks, and you will see what I mean. Although I would still point out that still means an attack sequence could cross over among multiple avoided attacks, all varying based on the time required for the tank to return to full health, taking into account incoming heals (regardless of predicted incoming damage I would add).

It is not having more or less avoidance for encounters, it is having the correct amount (outside of the correct EH) that balances the random avoided attacks into the middle of blocked attacks so as to both provide the necessary inter-heal buffer as well as not gimp threat and increase the number of times that spikiness happens (whether that be an avoidance streak or a lack of one). But again, what I am trying to say here, is that even in the case of having proper EH, you absolutely still must have the randomly avoided attacks. I speak about that from a healer perspective. All this talk about healers chain casting and 5 seconds is theorycrafting that I personally do not agree with.

Maybe that makes me a bad healer, maybe it doesn't, but personal experience in many fights like Illidan and Shahraz or Archimonde let me see that at least 1 out of 4 attacks (or something to this effect barring exact math) as a typical attack sequence HAS to be avoided to beat the encounter, assuming decent, yet imperfect, EH.

You can all argue that more avoidance increases spikiness, but I would still say that just like minimum EH there is a minimum necessary avoidance to avoid having 4 hits in a row occur, which WILL kill tanks because your concept of "5 healers sitting here doing nothing else but perfectly timed chain casted mana efficient heals" never happens except in "easy fights". "Survive 5 seconds without heals" is a bad concept, because in all honestly, it is a variation between "survive 1 second without heals" and "survive almost 10 seconds without direct large heals". Those are the two end points, not some random BS in the middle of it average time, from a healer perspective.

Edit: ok after a break from my rambling I think I figured out what I want to say in a simpler fashion. From a healer perspective, when designing raid class distribution and role distribution and healing targets, the minimum HPS required to have enough mana to end the fight with 0 mana as the boss dies requires the tank to have a decent amount of avoidance assuming a less than perfect EH.
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On a more controversial note, I would also add this statement, which I know will I will probably get flamed for.

It is the avoidance that appears to smooth out incoming damage from a healer perspective. Even for a tank with awesome EH that minimizes the size of each hit, over a given sequence of 10 attacks, the 2-5 dodges are what appear to reduce the variation in the little green health bar on average. Bosses all seem to have fast attack speeds from a healer perspective, barring a few gimmicks, everything seems 3 seconds or faster. The closer I can change to reactive healing to be mana efficient and go away from pre-emptive heal spam, the more I feel likely to beat the encounter.

It is extremely rare to see a reactive healing encounter anymore given the spike damage of BT/Hyjal. It seems entirely to consist of pre-emptive healing, and mana efficiency management from that perspetive, in a boss fight, seems to just consist of the right rank and some basic choices. Any waiting for damage causes a tank death, even as only 1 out of 3 healers.

All I can say, from personal experience, is that spike damage on the tank happens all the time, EH or avoidance geared, which forces me to pre-emptively heal. And even given the fact that the heal is going to land regardless, I expect and pray for you to dodge the next attack, because my goal is to get you topped off. My goal is avoid feeling like I have to cast a huge followup heal in the midst of my current huge heal. At least, that is my "feeling". When I see you take the 3rd consecutive hit in the midst of my first incoming spam heal in my chain, I just know you are more than likely going to die.
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I think where am I struggling is bringing this down to a real game level. I've gemmed and enchanted entirely for stamina, and I avoid about 20% less attacks than other tanks in my guild that have gemmed and enchanted for avoidance.

I think the question boils down to, do we need to buy some Dodge gems? As a Paladin I've always pushed to get into the HP ballpark as warriors and that meant stamina out the jing jang.
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