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12 commentsCurrently, PTR 3.22 unbreakable armour gives +25% armour and the glyph takes it to +30% (tooltip on glyph is a bit confusing).
If you compare that to bone shield at 15 seconds, giving a flat 20% reduction on top of your normal tank armour, I find that bone shield is ahead on total damage reduction. I modelled this in a google spreadsheet.
I used example armour of 25123 unbuffed and 27858 buffed.
Unbuffed, UA leaves you taking 32.66% of the damage on you, whereas bone shield on your armour leaves 30.20%. Smaller numbers are better. Glyphed, UA is 31.18% meaning bone shield is still ahead.
I think UA glyph should be changed to approximately 5% flat damage reduction, and the UA duration normalised to 15 seconds.
Vampiric Blood and bone shield are already 15s when glyphed.
This proposal is on the USA wow forums.
Another factor is that UA does not multiply the armour from buffs. Source. This means a raid-buffed tank gains less than a 5-man tank.
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Good posts!
I agree (I even made a similar comment about bone shield’s strength) that BS will be better with it’s new cd. It has a better damage reduction than other DK tanking talents.
BUT, it only reduces damage when it’s up, and of course charges are consumed by taking hits. SO, even glyphed it will only have 4 charges, meaning more than 4 hits in a minute will remove it, and the next hit will not be reduced at all. Of course, UA may be up for even less time as it turns out.
My thought is that for intense trash pulls, UA will be very good since there’s a lot of hits in a short period of time which would consume BS quickly, but on bosses – when the tank has high avoidance – BS will be better, and that’s generally what it’s about, right? Frost has a few other nice talents to make up for it, but for a single talent point, in 3.2.2, it looks like it will be fantastic.
Twitter: gravitydk
I wonder if they have changed the internal cooldown at all on bone shield? I haven’t tested it, but… I wonder. Perhaps Blizzard predicted this issue and have given a slightly longer cooldown.
Not sure about the icd, but generally speaking, BS is good for slow, big hits anyway. If there’s a big (Vezax or Algalon-style) hit, BS reduces that, and you shouldn’t be hit by another big one any time soon. I seem to remember them also commenting that for BS to be affected, the hit had to be a certain percentage of your health (to prevent some small 200-point dot or trash add hit removing a charge).
At any rate, the super-simple bottom line on BS is: pre-3.2.2: glyphed BS can absorb 6 hits every two minutes. After: 8.
I drafted this comment last night, and reread it a few times. I couldn’t work out whether it was bollocks or not. Got up this morning and decided to post anyway – feel free to shoot it down if it’s wrong.
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I enjoyed the spreadsheet (I like spreadsheets!) but different levels of armour will give different answers won’t they?
It looks to me like bone shield’s mitigation is linear – whatever damage you took before, you will take 80% of it with bone shield up (ergo if you have more armour bone shield benefits you less in terms of raw damage mitigated). Having thought about it briefly, I think this gives a linear 25% increase in ETTL, but I’m not certain of that.
But UA gives you more bonus armour, the more armour you have. Does that mean that at high levels of armour (perhaps combined with a Furnace Stone) UA is better?
Armour’s mitigation benefit is nonlinear – going from 40% damage taken to 32% damage taken is less of an ETTL benefit than going from 32% damage taken to 24% damage taken. You also have diminishing returns, so that the relationship of armour to damage reduction alters in a non-linear manner and there is a cap of 75% on mitigation. But then add in the fact that the higher your armour the more that UA will benefit you in terms of an absolute increase in your level of armour and yes already I have brain ache.
My gut feeling is that dimishing returns and the cap normally cancel out the nonlinear benefits of armour. This leaves the fact that you get more UA bonus the better your gear is, so UA may be slightly worse than bone shield at current gear levels but will scale better than bone shield until you get pretty close to the armour cap. Someone needs to do the maths though.
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Well, a couple of thoughts on your post, Everblue.
First, yes, UA should scale with armor. Unfortunately, it would take a hell of a lot of armor to scale as high as the reduction as BS, and as you do point out, there’s diminishing returns with armor – eventually an effective ‘cap’ on the mitigation offered will be encountered. I don’t know the maths either, or the scree point at which these diminishing returns would happen – that’s something for a tankspot thread and more time-intensive research. But my hunch (similar to yours) is realistically, UA isn’t going to get the same raw mitigation as BS even with several tier increases in armor levels. UA’s strength comes into play when it can mitigate an unlimited number of hits while it’s up, something BS cannot do. In addition, the strength increase during UA will provide both parry mitigation and threat.
I was a little confused by your damage reduction statement, but I think I understand what you meant now. Yes, reducing 8% more overall damage is better the closer to you get to 0% (because of course, going from 40-30 is 25% less damage taken while going from 30-20 is 33% less damage), but as you follow up to say, that’s not the way it works in practice. Diminishing returns means that 20% more armor when you’re at 50% armor mitigation mitigates more damage than 20% more armor at 60% armor-based mitigation.
As I said earlier, that means while in theory UA gets better with better gear, in practice it scales poorly because armor doesn’t really increase all that much with each tier, and it suffers from diminishing returns. On the other hand, while BS doesn’t ’scale’ in the sense that it is a flat damage reduction no matter what gear you have, in practice it scales extremely well with gear. While parry and dodge (and block) also suffer from diminishing returns, in general they get MUCH better with each tier increase, and BS becomes MUCH more effective going from 40% avoidance to 50% avoidance, and even BETTER at 55% avoidance (our DK MT has attained over 55% avoidance in incomplete T9 gear, unbuffed, so it’s fairly easy to do). For anyone confused by this, it’s because both talents are designed to be ‘on-use,’ that is, not always up. UA is time-limited. BS is limited by the number of hits it absorbs. If you get hit less often, less charges get used up, and it’s ‘effectiveness’ is increased by mitigating a larger percentage of the hits that actually land.
Bottom line is that the two talents offer different mitigation mechanics, and will be ‘better’ for different situations. My general opinion is that BS is a better talent at high levels of avoidance and all things being equal it is the single best mitigation point you can spend. However, you have to go so deep into the unholy tree that unless you want to be an unholy tank (with less threat and poorer complimentary tanking talents), that it may or may not be worth it.
My understanding* is that the way that diminishing returns on armour works is that the increase in expected time to live is the same whatever your level of armour, but I do not know how this behaves near the armour cap.
*limited
I do take your point about armour not going up much each tier, but there are lots of bonus armour necks, weapons, rings and cloaks around now, plus some trinkets with large bonus armour procs. It’s possible to build quite a high armour set.
I agree it’s possible to build a 58% avoidance set pre diminishing returns. I’ve got 28% dodge and 20% parry (ish) in my 10 man gear, and I assume my miss percentage is around 10%.
I’m happy to accept your more informed opinion about DK tanking though! I just like the maths…
Everblue´s last blog .."They come to me with progress reports…"
Oh – and there are no diminishing returns on block. Or miss, I think.
Everblue´s last blog .."They come to me with progress reports…"
Twitter: gravitydk
The time to live you gain from 1k armour is linear against a fixed incoming DPS, so if in blues you gaining 5s life from the armour gain, you’d also get that same 5s if you were in Tier 9 armour. The DPS reduction from armour, whilst curved, is not a steep curve between the UA and non-UA of gaining ~6K armour. That’s why it’s kind of like effective health. I’m not sure if that’s what you were saying or not Everblue. Formula & chart here http://www.wowwiki.com/Armor
I agree the thing about bone shield is it scales in a useful way (ie. with more avoidance) and also it reduces all damage, not just physical. It’s also got a wonderful bonus of being put up pre-emptively when you’re not exactly sure about the damage timing.
UA just doesn’t excite me. Loads of physical mitigation like Hinen said on trash… which really isn’t why we have big tank cooldowns in the first place.
UA and Vamp Blood are just better, to my mind.
However, if UA gets to keep a 20s duration whilst the other two are around 15s, then equation is a little different. I expect the duration to be nerfed but maybe they won’t. Perhaps that’s how Blizzard are balancing it; shittier tank cooldown but it’s up for longer.
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Vamp Blood is a wonderful talent as well (and as I’ve been blood tank for some time, it’s the one I use). I’m glad the cd is being reduced, because I tended to save it only for “oh crap” situations, but the DK tanking playstyle is built around defensive (and health-regenerating) cds. In general, I try to only have one solid defensive cd off cooldown at a time. That way, I keep my healers happy and have much less effective damage taken overall, but if something goes wrong, that one cd is kept in reserve to save me. I’ve found that rarely will having multiple cds do much more in a bad situations. The only exception to this is known predictable damage spikes, most notably on Sartharion 3D but more recently on Gormok’s impales. In that case, I might save a couple of cds to ensure survival.
As far as UA goes, yes, it’s a weaker talent than VB or BS in my opinion, but the frost tree has some nice complimentary ones. I’ve never been fond of the AMZ talent in unhohly or Will of the Necropolis in Blood, while the defensive talents in frost are at least worthwhile. After 3.2.2 drops, I’ll probably play around a little more with each tree for tanking and see where I end up.
Twitter: gravitydk
I quite liked AMZ actually, it’s like having 20K more HP for a moment, and like the Plan B style of WotN (like a backstop). You’re right about complimentary talents, like Frost does have more avoidance and flat damage reduction, the catch is I would prefer to take 3-5% more damage during 90% of the fight, if I could then pop huge cooldowns for the BIG HIT. I like bone shield for that.
Ironically, my other ‘oh crap’ button is my Draeni racial (and trinket); those two give me a few seconds of about 4k more health as you say. It’s not that I disliked AMZ’s effect, just that I had to spend so many points for that I’d rather put elsewhere. For one thing, it was too situational and I didn’t use it often (but yes, when you needed it, it was awesome) The 4 points in Imp Rune Tap, on the other hand, I use all the time on cd. It gives me a good amount of health and glyph can assist healers who are starting to get behind on damage. WotN functionally wasn’t as much like the ‘old’ (pre-nerf) Cheat Death talent rogues had as I would have liked.
Another thought on UA: in 3.2.2 it becomes even more of a tanking (and perhaps pvp) talent. In my dps DW frost build I used it as a burst talent in a tree that is lacking much burst, but with UA losing some of its strength it’s clear Blizz wants it to be mostly a tanking talent.