The Case Against DW Frost Tanking : Parry Haste, Threat, and Beyond

10:56AM on 03 Sep 2009 by shieldbreakr
2 Comments

As of late, a lot of mumbling has gone on concerning the new, improved dual-wielding death knight. I have already posted at length about dw frost dps, so I will instead take this opportunity to present arguments for the new improved DW Frost DK Tank in 3.2. One of the constant conversational arguments is "DW DK Tanks lose because of parry haste". Another is "DW brings more threat". Well, we'll see..

For those of you living the blessed existence to not know what parry haste is, it is a mechanic by which an enemy parries you, causing his next attack to happen 40% faster. However, like all mechanics in warcraft, it is not that simple. The parry haste only affects the time remaining on the next melee attack swing, so if their attack speed is 2.6 seconds and they parry at 2.5 seconds, the next attack will happen in .06 seconds. Conversely, if the parry happens at 0.6 seconds into the swing timer, their next attack happens 1.2 seconds later instead of 2 seconds later [ 2.6 - 0.6 = 2.0 * .4 = .8, 2.0 - .8 = 1.2 sec]. This makes modeling parry haste a bit difficult because boss swing timers vary, about 350 different stats and states effect parry, and the effects of parrying the offhand in a dual-wield situation seem to just mess everything up. The following is how I have reasoned out the worst case scenario for the DW DK Tank: that the offhand is separately parry-able in ToT enabled strikes, that you are attacking twice as often, and battling the worst type of boss: pure physical damage with a slow swing timer.

Bosses have 14% parry and 6.5% dodge from the front when you have 0 expertise. That means that the main trade off as a DW tank vs a "traditional" tank (2h dk/war/paly) is the extra parry-able attacks that you will be throwing at a much faster pace compared to a 2h tank. With 2.6spd weapons, a DK will execute ~600 attacks ,84 of which will be parried, against the average boss (5 min fight, attack from the front, parry-haste boss). 2h DK tanks will throw only ~235, causing 33 parries. So DW will evoke 34 extra attacks over five minutes compared to a 2h tank's 13 extra attacks. While this sounds bad, they don't all happen at once unless you are very unlucky, in which case I would recommend you start reading some of my dps threads. Spread out over 5 minutes, you're incurring ~2 extra attacks per 30 seconds over "traditional" tanking. This means a DW tank without any of the DW bonuses will take 5.4% more damage than a traditional tank in the worst case scenario where all parries happen simultaneously with swing timer resets. In reality, the parries will happen all over the swing timer and average to the halfway point of any given swing timer, so the real damage differential approaches 2.7% more damage when 2h frost is the baseline.

DW Frost also gives up Rune of Stone Gargoyle. SG provides you with +25 def outside of the diminishing returns defense cap and +2% health. It is the best tank enchant in the game and it's all DK. I would kill for a 1h version that gives +12def/+1% health (rune of grave guardian?), but that is another subject. The logic of this rune is that there are 1h tanking weapons built for DK's (two in the entire game over iLvL 200) and they all have ~+12 def on them, so stone gargoyle provides the +25 defense and also something for us def capers in the form of 2% health. Additionally, Stone Gargoyle moves the defense soft cap up from 540 to 565 (extra 0.6944% dodge/parry). In SG's place, Rune of Swordbreaking is used for +2% parry (x2) outside of the DR. This means a DW Frost DK using SS over SG on both weapons will have 2% less life, 1% less dodge, and 3.066% more parry. A net win after sufficiently high HP levels [40k+], in my opinion. This means that a DW tank actually takes 0.633% more damage than a traditional tank after a basic rune shift.

If 0.633% more tank damage is "raid ending", you're either breaking HM Uld or pugging Naxx right now. Besides, the increased threat should more than make up for the increased damage. If your dps'ers are anything like mine, they are just chomping at the bit to keep below your threat for the first minutes of a battle. Traditional frost tank spec (15/51/5) accounts for ~700 TPS less threat than new DW Frost Tank spec (12/52/7). Either way, it's worth a shot when you think your healers are not out of their depth and DPS making a tight enrage timer is that problem. I have been alternating between 2h and DW for a few weeks now and I notice that it is easier to keep threat up in difficult situations as DW, but I take a noticeable amount of increased damage against slow hitting bosses when I am getting unlucky, but that is pretty subjective admittedly.

Note: As one small addendum, if you followed my previous post on DW frost, you also know that DW builds require less hit (as weird as that sounds) than 2h builds due to the blessing that is Nerves of Cold Steel (+3% hit, +15% offhand dmg), making the soft hit cap for DW Frost 162 hit rating. In place of this 100 hit, you could perhaps fit 100 expertise, lowering your parry ratio by another ~3%, making DW Frost DK Tanks take 1.5% less damage than their traditional tank counterparts. However, this comes with a very hard trade off: Spell misses. I talked earlier about the 600 attacks DW DK's throw in 5 minutes, well there are some attacks missing from that: Icy Touch and Howling Blast. These are spells and as such are subject to the 17% or 446 hit rating (14%/367 with Virulence). Additionally, Dark Command and Death Grip also fall under spell hit. Dropping your hit to 162 hit rating, you will miss with spells approximately 13% of the time (10% with virulence). As such, your milage may vary with this new emphasis on expertise. However, this should not prevent you from stacking a bit of expertise when you can stand it, as getting as little as 50 points of expertise will lower the difference between DW and 2h tanking to less than 1%. Also, if you are the type to play with talent tree variations, picking up Veteran of the Third War will put 6 full points of expertise in your pocket and put you 1/4th of the way to the soft cap of 26 (where dodge is no longer affected). Lastly, Orc DK's have 5 points of expertise while wielding axes.

The two DW tanking weapons for us: Serilas, Blood Blade of Invar One-Arm and Broken Promise . If you see other 2.6+ speed weapons with def/dodge/parry, please feel free to add a comment.

Calculations:
*All numbers sourced: Elitist Jerks
**Parry Haste
Bosses have 14% parry, 6.5% dodge
*Soft expertise cap (where dodge disappears) is 26.
*Hard expertise cap (where dodge and parry go away) is 42 (unattainable for DK).
- Expertise Rating: 32.78998947 ER to 4 Expertise. [8.19749 to 1]
- Expertise: reduces chance to be dodge/parried by .25% per full expertise point up to 6.5% dodge, 14% parry
- Which means you will be parried 14% of the time with 0 expertise.
- Avg boss fight: 5 mins
-- avg strikes that can be parried per min: 120 for dw, 47 for 2h.
-- Rotation: 10 attacks / 20 seconds parriable, auto attack @ 2.6 x 2, vs auto attack @ 3.6 x 1.
-- means 600 attacks over avg boss fight for dw, 235 for 2h.
-- means 84 parries for dw, 33 for 2h.
- avg boss attacks 2 seconds apart. (300 attacks in 5 mins)
-- worst case dw dmg (full 40% haste): increases boss dmg by 11% (34 extra attacks)- 84 * .4 = 33.6 extra attacks.
-- worst case 2h dmg (full 40% haste): increases boss dmg by 5% (13 extra attacks)- 33 * .4 = 13.2 extra attacks
-- Actual difference is really 5.5% more dw dmg, 2.5% more 2h dmg.
- 100 exp Rating (3.04% dodge/parry reduction) : The point at which dw and 2h are even if 2h has no expertise.
** Loss of Stone Gargoyle
- 565 Def Cap -> 540 Def Cap == 25 extra def over cap * .0118 = .295% dodge/parry by lowered cap.
- 565 w/ dw frost is still possible, but will be affected by 540 DR, which means the 25 def buys you .3066% d/p == 1/((.021275)+(.956/.295)) = 1/(.021275+3.241) = 1/3.26195 = .3066% dodge/parry.

Tags: dualwield frost tanking parryhaste 12/52/7

sick

09:28PM on 03 Sep 2009

Good advice, nice post.

shieldbreakr

09:30PM on 03 Sep 2009

Thanks, Sick.

Of course, first ToC raid after posting this, I pick up ye olde 2h'er and head in to knock some heads. My hypocracy knows no bounds, it seems