"If I post lots of words, people will think I know what I'm talking about!"
You've said two things here: jack and shit. You had your chance, now enjoy your ban.
Here are the specifics I came up with when looking at the mitigation numbers:
Before Cooldown Mitigation from Talents
Rule 1: Only counted talents deeper than the "requires at least 10 points in X spec" tier, or Tier 3. I will still mention all talents in the tree, however, that fall under mitigation.
Rule 2: Situational talents, like Acclimation, although not strictly on a cooldown, were not counted because they do not provide mitigation across the board at all times. The main purpose of mitigation is to create consistently lower incoming damage.
Frost has the Toughness (Rank 5) talent, but I didn't want to count it into the spec's overall mitigation over other classes since just about any tanking spec, regardless of which tree you use primarily, will be putting Toughness in there somewhere.
I assumed that Frigid Dreadplate (Rank 3) was a mitigation of 3%, not avoidance. I was incorrect in my understanding of this, and thus it contributed to a bad assumption on my part (lesson learned: Always double check). And, while it's a nice talent that is fairly unique in the deep-tree of the 3 specs, it isn't mitigation and can't be counted into the total.
Since the only other talent that provides any sort of mitigation after Improved Frost Presence (Rank 2) is Acclimation (Rank 5), that leaves any pure, before cooldown mitigation at only 2% unless you take acclimation, and I'm under the impression that most Frost Tanks do not.
So, in the end, Frost has 2% extra mitigation for their talents. Lower than my initial thoughts.
I also discounted Rune Tap and [url=http://www.wowhead.com/?spell=49489]Improved Runetap (Rank 3)[url], because healing is not mitigation, it's healing. If mitigation were healing, then discipline priests would have their shields counted as healing on healing meters, but they don't because they do their job through healing AND mitigation. The only healing that can be considered for mitigation is consistent healing, which provides a stable, mitigation-like effect for a fight. Rune Tap does not, and though it is a very valuable talent in many ways for Blood Tanks, it is not mitigation.
I did count Will of the Necropolis (Rank 3), which is actually a very good mitigation talent, it is, however situational. It serves its purpose, however, which is to stop you from dying if you are close to dying, without making you immune to death. You can still die, but your healers have a bit of extra room in which to save you, or you can potentially save yourself with a Rune Tap. Either way, most often you do not want to be below 35% health as it is, which means that this talent is quite situational. It will likely be used a lot, but it's tough to call it true, pure mitigation. And since I don't know the numbers on the average numbers on when a 45k hp (That was the hp number I chose for a fully buffed Blood Tank) gets below 15750 (35% health) it's tough to calculate the actual mitigation effect throughout the entirety of a fight. Suffice to say, it's an excellent tanking talent.
For consistent, pure mitigation, I'm unsure of the numbers for blood. It is certainly not 15% of the damage done in a fight, the question is whether or not the tank is low enough often enough in the fight that more than 2% of incoming damage is mitigated. Also, because the effect can only happen once per 15 seconds, it is not providing consistent mitigation throughout a string of attacks at low hp, which leads me to guess that in a typical encounter, it more often than not, does not prevent 2% of the damage done.
Unholy really does not have much in the way of mitigation before cooldowns, in fact, the only talent it does have is Magic Suppression (Rank 3), and I don't have the numbers of how much magical damage is done in a particular boss encounter in which to say that the 6% mitigated is more than 2% of all damage done. In fights like Hodir I'm certain it is strictly better than Improved Frost Presence (Rank 2), but I'm not sure how many fights that would also be true on.
So, Unholy has slightly better mitigation on heavy magic fights, but I don't believe (Without the numbers, sorry, I don't have all of the pretty tools most people have to analyze their fights) that enough damage is done to the Main Tank of a magical nature that 6% overcomes 2% to all damage done, including magical.
In the end, the actual numbers of mitigation would require a bit of additional number crunching in order to find out how much damage is mitigated by Magic Suppression (Rank 3) and Will of the Necropolis (Rank 3) throughout each boss encounter in Ulduar. Until that math is done, the only certainty is that Frost has 2% pure mitigation over all of the other trees before cooldowns. It is less than I expected because of some erroneous assumptions, but is still a significant amount.
> I'll do a post on Cooldowns later.
> I want to be as accurate as possible, any numbers that I do not have that you might, feel free to share in a PM and I will give proper credit where it is due. This is specifically in reference to how much damage can be expected to be mitigated by the talents mentioned at the end.