With the talent and itemization changes of 2.3, Tankadins are faced with more options than ever in terms of available stats to increase threat. I decided to take a look at the relative effectiveness of these stats in order to help Tankadins better make decisions about their gear. There are 4 stats worth mentioning when it comes to Tankadin threat: spell damage, spell hit rating, hit rating, and expertise rating. The threat effects of these are summarized as follows:
Spell damage -- increases the damage dealt by our spells (and healing done by heals, though this usually isn't relevant to tanking)
Spell hit rating -- reduces the frequency of "miss-resists" on spell abilities. The following abilities can be miss-resisted:
JoV 5-stack hit
JoR/JoV
Holy Shield
Hit rating -- reduces the frequency of melee attack misses, affecting both our white damage and seal damage (since misses do not proc seals). Avenger's Shield and (as of 2.3) Righteous Defense misses are also reduced by hit rating.
Expertise rating -- reduces the chance for our melee attacks to be dodged/parried, having similar effects on our threat to hit rating. Does not affect AS/RD, but does reduce incoming damage slightly due to fewer parries.
Analysis of threat stats:
Spell damage: In a full threat rotation, 1 spell damage provides about .5 tps. The calculations have been done more extensively in other threads so I won't repeat them here, but if you want more information check out:
http://www.failsafedesign.com/maintankadin/viewtopic.php?t=241
An important note for the equivalence figures in the stats below. To figure out at what tps each stat equals +dam, I simply set up the equation:
.5 = X% * Y TPS
and solved for Y, where X is the % damage increase from the stat. One consequence of this approximation is that the tps numbers refer to tps from damage only. Threat from energy regen and healing tends to be much more variable and so I haven't attempted to capture it here, but generally I've found that 15-20% of my threat comes for energy regen (the vast majority being Spiritual Attunement mana gains) and self-healing through earth shield and Prayer of Mending. Thus, if you're comparing to results from a threat meter or parser, you'll generally want to add 15-25% to the cutoff numbers listed to get the cutoff in terms of overall threat rather than threat from damage only.
Spell hit: For a very rough look at spell hit I will make the following simplifications:
-- 37% of our threat comes from miss-resistable spells (thus far parses indicate this number is about 35-39%)
-- These spells have a miss-resist rate of 17%
-- We have taken the 2.3 Precision talent
Given this set up, 1% spell hit will give us a .35*(.01/(1-.14)) ~= .41% increase in threat
Since 12.62 spell hit rating = 1% spell hit, a single point of spell hit rating would provide a ~.032% increase in threat. Thus, under these assumptions 1 spell hit rating = 1 spell damage at a threat output of about 1560 tps
Hit rating: The main assumption here is that white damage + SoR account for 35% of overall threat generation. We also assume 6% miss, 6% dodge, and 15% parry by the mob,, which includes precision.
Thus, 1% hit provides a .35*(.01/(1-.27)) ~= .48% increase in threat generation. 15.76 hit rating = 1% hit, so each point of hit rating provides a ~.030% threat increase. In other words, 1 hit rating = 1 spell damage at about 1660 tps
Expertise rating: Here the same assumptions will be used as with hit rating.
1 expertise is -.25% dodge/parry (.5% combined), which provides a .35*(.005/(1-.27)) ~= .24% increase in threat generation. 3.94 expertise rating = 1 expertise, so each point of expertise rating provides a ~.061% threat increase. In other words, 1 expertise rating = 1 spell damage at about 825 tps
Conclusions:
In summary, taken solely in terms of threat, most Tankadins should prioritize threat stats in the following order:
Pre-T6:
spell damage > expertise rating >>>>> spell hit rating > hit rating
T6+:
spell damage = expertise rating >>>>> spell hit rating > hit rating
The general take home message is that our 2 primary threat stats are +damage and expertise rating. The 825 TPS from damage only mark roughly corresponds to about 1000 overall tps...generally hit around early T6. Hit rating and spell hit rating are nearly identical in terms of their threat contribution, but each is about half as effective as +dam or expertise rating. As a small editorial comment, note that if hit and spell hit were combined into a single stat, the resulting stat would provide a .062% increase in threat per rating point, almost identical to expertise (hint, hint Blizzard).
That these calculations are only done for single target tanking. In multi-target situations spell damage will dominate even more due to the huge role consecration plays in AoE threat.
There are other factors to consider of course: the mitigation value of expertise (which I haven't attempted to calculate), or the reduction in AS/RD resists from hit rating which may be desirable on certain fights. In general however, I would conclude that most Tankadins are actually best off ignoring all threat stats except for spell damage. If you happen to pick up the others that's fine, but I wouldn't go out of your way for them.
Thanks to the many active theorycrafters who provided data points and ideas for this, and especially to Joanadark for the info on miss-resistable skills and to kalbear and cordelia for crunching the numbers on the T6 content parses.
Dorvan
Fri Nov 09, 2007 11:58 am
