Monday, November 9, 2009

A Look at Pushback Resistance

In my recent Moonkin Basics post regarding Talents I made the following comment:

This prompted the following comment from a reader:

For the record, I want to say that I don't think Pushback Resistance issue in the current PvE content. That is the exact reason why I didn't included Nature's Focus as a part of my core build in my Moonkin Basics post. However, he was so dismissive with regards to the value of Pushback Resistance that I fell it is necessary to address the topic more formally. In the following post I hope to show you why you may want to pay attention to Pushback Resistance in the future.

How Spell Pushback Works

You will experience Spell Pushback if you take damage while you are casting a spell. However, how it affects that spell depends on the spell type. For a Channelled spell like Hurricane, tanking damage while channelling the spell reduce the spell's duration by 20%. For a spell with a cast time like Starfire, taking damage while casting will increase the cast time by 0.5 seconds. The good news is for both types of spell, only the first two hits will incur spell push back. So, spell pushback can only reduce your channelled spell duration by 40% total, or increase your cast time by a maximum of 1.0 seconds.

Unfortunately, the only way to reduce spell pushback is with the use of talents and buffs. I did some testing over the weekend and proved to myself that Haste has absolutely no impact on the cast time added by spell pushback. Fortunately, Moonkin have several tools available to them to combat spell pushback.

Celestial Focus - When fully stacked CF will reduce the Pushback on your Starfire and Hurricane by 70%.

Nature's Focus - When fully stacked NF will reduce the Pushback on your Wrath and most of your healing spells by 70%.

Barkskin - Your push back is reduced by 100% for all spells while Barkskin is active.

Owlkin Frenzy - Your push back is reduced by 100% for all spells while OF is active.

Concentration Aura - This is from a paladin. It will give you 35% resistance to pushback if you are in range of the pally.

These buffs stack additively. So, having Concentration Aura with Nature's Focus and Celestial Focus gives you 100% resistance to spell push back.

The Math of Spell Pushback:

For simplicity's sake lets make a couple of stipulations. Lets say that the average Starfire hits for 10,000 damage and takes 2.0 seconds to cast. Lets also say that the average Wrath hits for 5,000 damage and takes 1.0 seconds to cast. I know that these are not percice numbers but more accurate numbers are not needed to show the impact of spell push back.

So, using these numbers, both spells have 5,000 DPS if they do not suffer any spell pushback. With the first hit, Starfire's DPS will drop to 4,000 DPS (10,000/(2+0.5)), and Wrath's DPS will drop to 3,333 DPS (5,000/(1+0.5)).

As you can see, taking a hit will have a significant impact on your DPS. On top of that, a spell like Wrath that has a shorter cast time has an even larger drop in DPS due to spell pushback, because the amount added is not relative to the cast time. Of course, Wrath is more likely to avoid spell pushback due to it's shorter cast time. That will reduce the impact of spell pushback some, but it will still have a greater impact then Starfire.

So, what happens if we put a point in Celestial Focus or Nature's Focus? The DPS of Starfire will rise to 4,193 (10,000/(2+(0.5*(1-0.23)))), and the DPS of Wrath will rise to 3,610 (5,000/(1+(0.5*(1-0.23)))). For Starfire this is a 4.83% DPS increase and a 8.30% DPS increase for Wrath. The second and third point have even larger marginal impacts on your DPS. However, this benefit is only realized if you take damage.

Why Spell Pushback is Important

Some of you may be thinking: "I realize that pushback has an impact, but I don't get hit enough in raid for it to have a big impact."

As I said before, I agree that Pushback Resistance isn't hugely necessary in the current raid content. Naxx and Ulduar don't have a lot of unavoidable raid wide damage. ToC has a little bit more but it really isn't enough for it to be a big issue yet. On top of that Celestial Focus is a core talent of any moonkin due to the Haste it provides. Therefore, we are currently pretty well covered as it is. The question is, what type of damage will we see in ICC?

If you take a look back at Black temple and Sunwell, you will see that frequent damage was more of the norm then infrequent damage. In some of the fights like Bloodboil we were getting hit with damage every 2 seconds. If Wrath is 40% of your damage, and 50% of your wraths are getting delayed due to push back, each of those points in Nature's focus will now increase your DPS by 1.66% to 2.09%.

We are only just now getting our first looks at the bosses of ICC, and we don't know what they will look like in hard mode. As such, I can't make any definite statements about Pushback resistance being necessary in ICC or not. However, don't be surprised if you start to see a lot of high level moonkin starting to make the switch. The reason is because Pushback can have a huge negative impact on your DPS if there is enough damage being thrown around.


Anonymous said...

and if we choose to take the talent int rtesto tree. which one should we drop? 2points in furror(4%int) or MoTW?

any math there?

lissanna said...

I remember working really hard at some point to GET moonkin pushback resistance. However, I think what we get from Celestial Focus is fine right now. Starfire is more problematic than wrath, IMO. Also, if we are taking heavy raid damage, then owlkin frenzy starts looking a lot more attractive...

Graylo said...


Erdluf had a good point in my original post. DPS wise the two are very similar, but with Imp MotW you also get a little extra stam. Therefore, I would drop Furor before I dropped Imp MotW


Owlkin Frenzy may also look more attractive in ICC, but you have to remember a couple of things.

First, where are you going to take the points from? I only have two floating points at the moment and Gale Winds maybe important also. You never know.

Second, the folks over at EJ have proven that not all damage will proc Owlkin Frenzy. So the question becomes will the damage we take in ICC proc it? If it doesn't then OF is no better then it is now.

Lherin said...

The dps balance in BC called for pushback to be a big factor in encounters. It was my impression that in WoTLK they wanted to move away from that. Thus why they made a lot of unavoidable damage not cause pushback. The current melee/caster balance seems to call for pushback being present, but not debilitating.

Given this, I don't think we will see any unavoidable pushback in ICC. The amount of avoidable pushback is difficult to judge though.

Porom said...

I have been 2/3 Nature's Focus since they added 2% stats to IMotW. I couldn't agree more with you on this subject.

A couple of things to note as well with IMotW VS Furor is that 4% Intellect is better than 2% Intellect and Spirit. The Stamina as Erdluf mentioned is nice but generally speaking Druid's do not lack survivability. I opt to spec into Furor myself.

Also i'm not entirely sure if this is 100% reliable, but I have noticed that damage that causes knockback procs OF. It seems to be a good rule of thumb.

This is by far one of the best subjects you've addressed, I enjoyed reading this one, short as it may be.

Randomsmo said...

Calculations seem to assume that your base spell pushback reduction is 0%. On fights with damage that can cause pushback you are likely to have a paladin with Imp Concentration Aura, which provides 50% base pushback reduction. That should actually increase the value of the first and second point of Nature's Focus slightly.

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Aeiedil said...

I actually toyed with Owlkin Frenzy a bit on early TOTC and actually quite liked the effect. Currently I have specced slightly differntly again however feel confident that switching over to Owlkin Frenzy may not be a bad idea, especially if under constant damage. The damage effect and mana regen is a nice additional side effect, considering it's effectively 10% of mana back when it procs. I believe I pulled points from mana regen to put into it for that reason.

Graylo, any idea what damage precisely doesn't proc OF? I did some tests and didn't really find much that didn't proc it, even standing in a cooking fire seemed to proc it. It may be that they changed it and then rolled back the change.

DJ Fatso Stupid said...

Most spells that deal raidwide damage these days do not cause pushback. Parsing my logs from a recent raid (I'm not playing a moonkin, but casters will get more or less the same number of pushbacks) I took only 20 pushbacks in a little over an hour, and pretty much all of them were against Faction Champs. 70% pushback resistance would come out to the equivalent of about 0.58% haste, or just under 0.2% haste per talent point. If there were not a fight where taunt-immune melee characters chose random targets to attack, it would be a lot worse. I think being dismissive of pushback resistance is appropriate.

Fert said...

As a Shadow Priest I have really come to love pushback resistance. It makes "DPS Harder" a viable strategy for a shadow priest to deal with most situations since u can just pew pew through most anything.