Usual disclaimer: the following information is as of the Mist of Pandaria Beta build 15913, released on July 27, 2012, and may not be accurate once future patches are released.
Now that Mists of Pandaria has a firm release date, and by conjunction our abilities and scaling coefficients are also fairly final, I have started doing analysis on how our Level45 and Level75 talents stack up against one another in a variety of fight scenarios. I compiled the latest subversion files in the mop branch (same as the now released simc-504-1 version for Priests) and started running simulations: 45 in total. All of these sims were done using 100,000 iterations on each profile to reduce the error range to an acceptably low level. In all, every combination of Level45 talents (From Darkness, Comes Light, Mindbender, or Shadow Word: Insanity), Level75 talents (Divine Insight, Power Infusion, and Twist of Fate), and the 5 different built in fight types that SimulationCraft offers to sim with (Patchwerk, Helterskelter, Ultraxion, Heavy Movement, and Light Movement).
First, let us look at the average DPS of each combination of L45, L75, and encounter types, grouped by encounter type:
As you can see, the type of encounter you’re in has a very large impact on how much damage you do overall. A good example of this is the difference between a Heavy Movement style fight and a Patchwerk style fight: 91k DPS vs 107k DPS (for the highest rated sim)! Excluding the Heavy Movement results, the other 4 fight types have very similar result values no matter the choice of talents taken, with the highest difference being Helterskelter (3.98%) and the lowest being Ultraxion (3.51%), while Heavy Movement shows a whopping 15.00% difference between the best and worst talent combinations!
If we look at this data a little more closely a number of important trends jump out. First, on all five sims, some combination of Shadow Word: Insanity and any of the three L75 talents rank 8th and 9th out of 9 in DPS, while three and two out of the remaining five rank 7th and 6th, respectively. Shadow Word: Insanity is not a good talent to pick up in any PvE encounter unless there is a very, very, very specific need.
Looking at the other side of things, four out of the five top DPS combinations for each encounter type have both Mindbender and Twist of Fate as their talents; the 5th (for Heavy Movement) is Mindbender and Divine Insight. In fact, every combination of the top three highest DPS talent pairings across all fight types has Mindbender as the L45 talent, while the DPS difference between the different L75 choices is, as an average, under 1%.
My initial thinking was to take all 45 sims, compute the stat weights for Int/Spell Power/Spirit/Hit/Haste/Crit/Mastery and do an average of them all where they are normalized to the value of Intellect = 1 PP, just like I have done in the past (but with far fewer sims). Using this method would give an overall indicator as to what pieces of gear would perform the best, on average, no matter what talents you choose to raid with. Once I had the data in front of me, however, I began to see the large gaps in DPS performance between the talent combinations. Would anyone really use a talent in PvE that was so mathematically inferior across the board (Shadow Word: Insanity)? Probably, but how often? For how many fights? What if someone doesn’t like to switch out their talents on a specific encounter by encounter basis? What about someone who just loves using a more middle of the road combination like From Darkness, Comes Light and Power Infusion?
As you can see, there are a lot of possibilities when it comes to defining the best stat weights for gearing priority. Lets take a closer look at a few of these, specifically the highest DPS for each of the 5 fight types, the two highest DPS for each of the fight types, and all 45 sims averaged together:
All of the stats are normalized around 1 Int = 1 Pseudo Point (PP). As you can see, no matter the stat weights that are chosen, Hit = Spirit and is the most valuable stat for Shadow (aside, of course, from Int and Spell Power). Spell Power’s value varies slightly, but is so far ahead in it’s PP value that a delta of 0.0025 between ‘best’ and ‘all’ doesn’t have any noticeable effect.
The differences appear when you begin comparing specific values of Haste/Crit/Mastery between the different value groupings. When we take all 45 sim values and average them (including all of the sims that have Shadow Word: Insanity), the stat priorities are:
Int > Spell Power > Hit = Spirit > Crit > Mastery > Haste
If you take just the best (or two best) from each fight type and average them, the stat priorities are (for both):
Int > Spell Power > Hit = Spirit > Haste > Crit > Mastery
This is an interesting, but explainable, difference. First of all: the value of Haste drops like a rock all the way to the worst stat (by a decent amount). This makes sense because Shadow Word: Insanity uses the last tick of Shadow Word: Pain to cast. Second: the value of Hit/Spirit when combining all of the simulations (including the very poor ones) goes up in value, showing yet again that missing with a spell is bad, especially since your overall DPS is much lower any misses will hurt you more — remember, the same set of gear was used for all tests. Also related to the second point, third: Hit/Spirit is the most important stat; again, missing with a spell is bad.
From this data it is easy to state that for all fight types, the optimal L45 talent to chose is Mindbender. For most fights (unless you are constantly running around, such as Atramedes in Blackwing Descent), the optimal L75 talent is Twist of Fate; for very high movement fights Divine Insight comes out ahead.
My suggestion when trying to decide how to gear is to use the ‘Best Two Per Fight’ stat weights — these will be the stat weights I use for my Best in Slot lists. I recommend this because the damage difference isn’t too high and also accounts for a larger sample size which will prevent any one super high/super low stat from skewing the PP value too much.
Notes and Resources
The SimulationCraft profiles used do not include any “Elite” or “Heroic Elite” items yet. I don’t anticipate these +7 iLvl items to change stat weights much if at all; however, if they do the change won’t have a large enough effect to change stat priority.
These sims were for fights that are single-target. Multi target fights may (will) have different results.
These sims are as of Mists of Pandaria Beta build 15913, released on July 27, 2012. Once a new build comes out, these values will no longer be 100% valid!