Hello Tanks
I have to admitt, my view on tanks and gearing has always been stamina+armour. While our beloved MT like Def rating.
I happened stumble over this article. Lets debate this topic
The Great Debate
So, what to do? We've had a lot of heated debate on this subject on the forums, and I think a lot of misunderstanding of positions on both sides. I believe the problem we are seeing in these discussions is one of extremes. Nobody is advocating stacking avoidance or mitigation to the exclusion of the other. You can't function without both; you can't not have both! 490 defense and 5/5 deflection guarantees that you'll have over 30% dodge/parry/miss. With basic heroic/5man gear and no gems or enchants, you're sitting at something like 11k health, 12k armour, and probably 35% avoidance. If you have Karazhan gear, again without gems or enchants, maybe 12k/13k/38%. This is your starting point.
What I (and many others) am saying is that once you're there, you have enough avoidance. There is no need to go out of your way to get more. It's time to focus on armour and stamina. The differential in avoidance between straight 490D and 40 extra dodge rating, and 505D and 80 extra dodge rating is about 4%. 1 time in 25, you will get a timely avoid to extend your shield block that you wouldn't have otherwise gotten. 4% higher chance to avoid something that you would not have otherwise. This is not a huge difference here, the difference is not 0-26% dodge. It's 22-26%. If you stack more avoidance than that, you maybe make it 8%, or one in 12 on shield block. But it's still a random variable. And you keep your health lower because of it.
The experience that a majority of people are drawing on is Karazhan and heroics. In these places, your healers can use reactive healing for 99% of the content. This means that if you dodge an attack, they don't need to heal just yet. If you dodge 3 in a row, great! Mana efficiency increases with your avoidance, and that's great since the number of healers is limited. So far as most people can see this makes avoidance very desirable, and in this context it is. If your tanking game is Karazhan and Heroics then avoidance is your friend (though Nightbane is a good fight for high stamina/armour due to his hard hits).
However, because of the game mechanics, Stamina and armour is the only real choice - when you're looking past Karazhan. Why? Because of healing and rage.
Most people don't look at the bigger picture of the raid's mechanics. Let's move into Gruul's Lair now. High King Maulgar hits like a truck in autoattack, and adds three special attacks into the mix (your healers consider the Whirlwind that pulses for 6000-ish damage each to be time for a breather here.) Gruul starts out hitting hard, and only gets harder as the Grows stack. Reactive healing is no longer an option now. If healers try to heal in reaction to the damage the tank takes, or doesn't take, then the tank is going to die. It really is as simple as that. The healers must be healing in anticipation of the damage coming in, in terms of keeping average healing per second higher than average damage per second. There is no break, and no point where you are not healing. You can interrupt a heal sometimes when the tank suddenly pops to full, but even that is a gamble against what the next hits are going to be. At this point, excess avoidance is a wasted thing, because all it means is that you got overhealed. Avoidance does not increase your healers' mana efficiency here. They are almost always casting those heals regardless of whether you avoid or not. If they don't, you die. This only gets more and more true as you move past Gruul to Magtheridon (10k cleaves and 7k normal hits!) and beyond.
This is where stamina and armour stacking come in. We've all read armour-stamina equivalence by now. Ciderhelm made it a hot topic on the warrior forums not long ago, it's been on this site since day one, and to be perfectly candid this is how it has always been even in BWL and Naxx before the xpac - this is nothing new. In this situation, your armour and health create a consistent damage stream that is far less subject to spikes and dips. This has three effects:
When the burst damage comes, avoidance leaves it to chance whether you will dodge one and be okay. Combined high stamina and mitigation makes it a constant to absorb the damage and leave enough time for the heals to come. Every extra hitpoint and every bit more mitigation combines and amplifies to make you that much harder to kill, and does it in a consistent fashion. There are fewer streaks where nothing happens to your health at all, and fewer streaks where you go down super fast. Everything is steady and predictable. There is enough time to heal, and you win.
Then there is rage. Avoidance means less rage. Less rage means less threat generated, and more conservation needed to do everything you need to do, like put shield block up. Less threat means longer fights, and the chance of someone pulling aggro is that bit higher. Less rage can mean you sit there hoping that you take a hit after the fourth dodge, so that you have enough rage to put shield block up! It's a trite old saying, but it is true: if you can't spend all your rage, even on a raid boss, you are doing something wrong. Avoidance limits your performance. This is my personal number one reason for disliking avoidance. I'm always looking for rage. If you're sitting there thinking "I always have enough rage, and I never lose aggro". I invite you to go find a well geared DPS and have them light it up to 1000+ threat per second while you're tanking. You need to understand how much they hold back normally. To be fair, on some fights this is not as much of an issue, but on others it's painfully evident.
If by adding armour and health you can make that damage stream consistent enough, lower the magnitude of the incoming damage per second, and increase your overall time to live from full to zero, then your heal team can start to use more long cast heals and fewer short cast heals. Not to mention that bigger health pool makes overheals that much less likely. This is what creates mana efficiency. This is the least of the effects since healer mana isn't usually an issue anyway, but given the changes constantly coming it may become more important (and it may free a healer to do something else anyway.)
The key concept here is this: You aren't trying to take less damage; you are trying to increase the amount of damage you can take. Once you wrap your head around that, it all makes sense. This is why you don't care so much about avoidance in the context of the 25 man raid boss, which is a much different game than Karazhan. If you're tanking Karazhan and heroics, knock yourself out with avoidance. However, it's a safe bet to say that the further into the endgame you go, you will ultimately find you want to choose gear with the best combination of high armour and high stamina. Get battlescar instead of elusion (and get some avoidance anyway!) Use maiden gloves. Socket with Solid Star of Elune (don't be cheap, it's imaginary money in a video game!) and enchant for stamina. Take an increase in the constant buffer instead of a reduction of the random. You'll have plenty of avoidance. Add to that the extra armour and health, and it makes your healers' lives less stressful.
