Originally Posted by Rahdik

ArP nerf aside that list most likely is not BiS for Mutilate because it is ArP heavy. Mutilate most likely takes Head, Chest, Gloves, and Shoulders (as it is the combo with the most expertise and the least ArP) and uses off-set pants. It most likely wont take some of the other pieces as well.

Don't quote me on any of this I'm just roughly looking at the gear and trying to stay as far away from ArP and as close as possible to Expertise for a Mutilate setup.

Originally Posted by TheDoctor

After all this discussion on Haste and stat ratings... It really started me thinking. I have been of the mindset that throughput and regen need to be measured in their own rights, and for a static score system I still believe that to be the case.

If you use a spreadsheet or some other means where the scoring can be dynamically calculated based on the current gear and by an outlined cast composition and time of encounter... Then you can come up with an accurate current weight. You can download my spreadsheet to see what I am talking about. It currently handles primarily Disc Priests.

So in updating this spreadsheet I was working toward a common single comparison system and used the acronym SHC for Sum Healing Capability. What I came up with is that all stats are throughput stats in some way shape or form.

SP/Haste/Crit
Fairly obvious that they are throughput stats and the means by which they provide the gains.

Spi/Mp5/Int
Not so obvious but here is the reasoning. If you operate with the base mana pool what is your capability to heal? Very limited no matter how much SP/Haste/Crit you stack. Through strict regen stats and through the additional mana pool of Int we increase our ability to produce healing and hence throughput. It is quite obvious that if we have mana we can cast and if we do not we can not. It is critical when converting these stats into a throughput equivalent that we understand the mana required, encounter length, and spell composition as these determine what the ideal level of mana regen to support that throughput would be. Anything above the regen required does not contribute to additional throughput, so in terms of throughput regen stats are soft-capped.

In example, Billy Joe the priest is healing an encounter and would like to cast a FH every 2 seconds (super simplified example). The encounter requires that this level of healing be maintained for 60 seconds. What is the regen required to support the throughput of FH at this rate?

FH costs 591 mana casting one every two seconds is 295.5 mana per second and correlates to a balancing point of 1477.5 Mp5. This is widely variable based on mana pool size, so evaluating at varying int / mana pool sizes we find that....
924 Int -> 17443 Mana -> Requires 0 Mp5 to support this level of throughput for 60 seconds and end OOM.
700 Int -> 14083 Mana -> Requires 303.91 Mp5 to support this level of throughput for 60seconds and end OOM.


Summary
Given a specific encounter you can determine the appropriate mana cost to support the spell composition and throughput required to fulfill your role in the healing lineup. Based on that mana cost and the regen stats you currently have, further regen stats may or may not have value. At any point you can say "I would have" casted more spells or more expensive spells given that my mana could support it, you are in a position where your regen may not be high enough.

From a mathematical evaluation of the stats Mp5/Int are the highest throughput stats for Disc priests until you reach the point that mana regen is no longer required at an additional level. The basic comparison would be Mp5>Int>SP>Haste>Crit=Spi, or very close there about... This is very dynamic so don't take that as the law or a static approach.

For Playing with my spreadsheet to look at the results, it is important to set the % on the 'Healing' tab as the composition of spells cast over the course of the fight based on your playstyle. If they sum to 100% then you are assuming chain casting the entire period of the encounter length set on the 'Talents & Misc' tab. Modifying those values changes the 'Mix Mana Cost' on the 'Healing' tab and impacts the 'Longevity' line that is visible on several tabs. I have it configured such that once the longevity is greater than or equal to 100% then regen stats do not contribute to SHC weights as you have reached the point of excess regen and should only be stacking the other throughput stats. One important note is that on the version currently uploaded Penance is assumed to be casted on CD.

Originally Posted by Auturgist

Armor penetration - WoWWiki - Your guide to the World of Warcraft

That link does a pretty good job of explaining all the ins and outs of ArPen for you.