So, this means that spell queuing works well with Starfire and Wrath casts with little haste. However, once you start getting close to the 1 second GCD, haste starts to have real issues with the spell queuing system.
Like a lot of you I was excited by the possibilities of all the changes changes introduced to the PTR last Friday. Its the first time I've every seen a significant number of buffs introduced outside of an expansion and I liked the changes, but it also made me nervous. Moonkins have stuck by the Starfire for Raiding/Wrath for PvP mantra for years, and all of a sudden this core principle of our spec seemed to be threatened. However, the more reading and math I do the more I realize things are going to stay the same. That is not to say that these changes are insignificant, I just don't think they are going to change our core play style as much as it seemed at first.
Before I get into specifics lets get one thing clear. These changes are only on the PTR. It is very possible and somewhat likely that changes will occur. Don't get your heart set on anything until it goes live. Now, lets look at some specifics.
In my last post I speculated that the Coefficent would be brought up to 0.8 from 0.76. Well, Dukes on the EJ forums did the testing (link), and saw the coefficent has been increased to 1.2. Obviously this is much more then I expected and it is now obvious that IS will be staying as a part of the Moonkin Rotation. Realistically this was probably necessary to keep the spell relevant. IS dropped out of our rotation in T5 content because it didn't scale as well with Spell Power, and it was in danger of having it happen again in T8 or T9 content.
I think Randomsmo said it best on the WoW forums:
NG is exactly the same for Starfire in 3.1, except it will effect multiple spells.
NG is exactly the same for Wrath in 3.1 (unless you had really horrible haste), except it will effect multiple spells and it *might* (this is unconfirmed, so don't get too excited) lower the GCD to prevent clipping.
There are two angles from which you need to look at this change. The first is a cast time perspective, the second is an uptime perspective.
From the cast time perspective this does almost nothing for Moonkin raiders. For Starfire, 20% haste brings an unbuffed starfire down to 2.5 seconds just like the live NG currently does. For Wrath, it brings the cast time down to 1.25 which is a nerf when compared to the live version of NG. However, the impact is minor once you start considering raid buffs and haste from gear. Assuming your specced correctly a moonkin is going to have an additional 11.41% haste from talents and Wrath of Air, and that brings our haste total to 33.67%. Now you need just12.21% haste from gear to reach a 1 second Wrath. That is just 400.45 Haste Rating. If your raiding 25mans consistently then your most likely already past this point. If your not I'm sure that raiding Ulduar will push you past it quickly.
Sure, you could gear differently so that you take more Crit and minimize your Haste rating, but I don't think that is very likely. I have a spreadsheet that I use to value gear items. I built it to eventually provide a comprehensive list of gear choices with a relative value attached to each. When I updated the model for these changes I was surprised at how little changed. The values changed but the ranks didn't for the most part. The fact of the matter is that haste is unavoidable, and anyone who gets to the higher levels of raiding will blow past 400 haste whether they like it or not.
From an Uptime Perspective this is huge. Lets remember one important thing. Cast time is determined at the beginning of the spell cast. So a 3 second buff will affect multiple spells even if it takes more than 3 seconds to cast those spells.
Without haste from gear, your Starfire will have a cast time of 2.24 seconds (3/(1.03*1.03*1.05*1.2) = 2.24). Therefore I think it is safe to assume that you will usually be able to start two Starfires in 3 seconds.
Wrath will be down to 1.12 seconds without any haste from gear (1.5/(1.03*1.03*1.05*1.2) = 1.12). Therefore I think it is safe to assume that you will usually be able to start three Wraths in 3 seconds.
So, we can calculate the theoretical Natures Grace uptime like this assuming a 40% crit rate for both spells:
SF NG Up Time = 1 - (1 - 0.40)2 = 64.0%Actual uptimes will be lower then this because of movement and casting spells that don't crit, but this is a significant increase over the live version of Natures Grace which would be a little less then 40% for both spells.
Wrath NG Up Time = 1 - (1 - 0.40)3 = 78.4%
So to sum up the section, from a cast time perspective this change change has little impact, but it will affect a lot more spells because Natures Grace will have significantly more Uptime then the live version of the spell. This is a buff for PvE moonkin.
I hesitate to talk about this because I don't have any formal understanding of the mechanic. I only know what I know from personal experience and random comments on various forums. So, this is a warning, I believe that what I'm about to say is correct, but I don't have a solid foundation to base it off of.
It is my understanding that WoW has a Spell Queuing system to help minimize the impact of latency and human error. The way I think it works is if you try and cast a spell a little bit before your current cast is completed, then the game will Queue the spell to start casting when your current cast is completed. It's kind of like a caster version of auto-attack, and it works great for longer cast time spells like Starfire.
However, for shorter cast time spells like Wrath the system starts to breakdown because the global cooldown get is the way. If your Wrath cast time goes below 1 second the queued spell will be unable to cast because the global cooldown blocks it. So the timing of your next spell cast is determined by when you press the button reintroducing the impact of human error and increasing the average time between Wrath casts. Even a small increase in cast time like a tenth of a second will increase Wrath's average cast time by 10% and have a significant impact.
I'll say it again that I don't completely understand the process, but this is one of the main reasons Starfire is currently considered to be a superior dps spell then Wrath.
There have been some interesting posts on the EJ forums discussing this subject. It is a little spread out over the thread but it starts here with post 485. Update: Erdluf did some testing on Spell Queuing. You can find his results here.
I don't want to rehash everything I did in my four part Eclipse series, but obviously with the changes to Natures Grace and Eclipse there is an impact. If these changes go live I will update the analysis, but I want to just give you a summery now. Murmurs also did some nice math regarding this change on the WoW forums. you can find it here.
Spell vs Spell:
I've run the numbers for the hypothetical moonkin I used in my Eclipse post who had 2000 Spell Power, 35% crit, and 6% haste from gear. Under these conditions the average Starfire with Eclipse will do 3,499 DPS. A Wrath cast using the same stats will do 3,791 DPS on average. Spell vs Spell a Wrath cast with eclipse will do 8.3% more damage on average than a Starfire cast with Eclipse.
Rotation vs Rotation:
While the Spell vs Spell view is all fine and dandy we don't cast spells by themselves. We cast them as a part of a rotation, and the rotation view of Eclipse is not kind to Wrath. Using the hypothetical moonkin, an Eclipse rotation that favored Starfire did on average 3297 DPS. An Eclipse rotation that favored Wrath did only 3301 DPS. I ran the numbers at higher levels of gear and Wrath did improve relative to Starfire, but at most Wrath's advantage was at most 2.5% to 3% and this is ignoring the impact of Spell Queuing. If you add a tenth of a second lag to Wrath its advantage is completely erased and then some.
I can't help but concluding that the Starfire rotation is still the superior rotation if these changes go into affect, but that does not mean that this change is meaningless.
This change helps us in three ways.
1. First, if your looking for a more stable DPS rotation then the Wrath rotation is for you. It has a 100% chance on a SF crit and the buff is a straight damage buff. Therefore it is not affected by RNG nearly as much as a Starfire rotation is.
2. Second, this change limits the impact of mistakes. We've all been in situations where we get to focused and accidentally proc the wrong Eclipse. Now that the Wrath buff is 30% this mistake isn't as costly as it is on Live.
3. Each boss has its own issues and the all favor one style of casting over another. Stand and Nuke bosses are great for long cast spells like Starfire, but in high movement fights like Thaddius, Starfire can be an issue because you have to move before you can complete the cast. Therefore Wrath may be better for high movement fights because you will be able to get more casts off.