By popular demand, here is some research and math into unholy DKs that I whipped up. As with my Frost post, I may have missed some stuff or calculated something incorrectly. If that's the case please let me know so I can make changes. Thanks to everyone who submitted data, and you for reading!

**TLDR**: See my stat priority and gear suggestion at the bottom.

**UPDATES:**

**April 1, 2015 - Added a note about Mastery/Vers interaction at high mastery levels.

**Special Notes:**

(*) means I assume it's correct if not bugged but I didn't test it. I'll put this next to things I take for granted.

(**) means I actually tested this to prove that it is indeed this way. For brevity, I didn't outline how, but I can if requested.

(?) means I'm not sure, but if someone could test this somehow, it would be great

Let's start with seconday stat ratings and how much damage they contribute.

**Rating points required for 1% increase (** tested this myself):**

Haste 90

Crit 110

Multistrike(MS) 66

Mastery(MA) 44

Versatility(Vers) 130

Let's take a realistic but nice looking number of how much of each stat you could stack, say 1000 rating points.

**For 1000 rating points you would get:**

11.1% Haste

9.09% Crit

15.15% MS

22.73% MA

7.69% Vers

In addition, stats scale linearly. So adding 11.1% Haste when you have 40% has the same impact as adding it when you have 0%, assuming you don't hit a cap.

**NOTE:**Crit and MS are nerfed in PvP! This may be obvious to some, but a lot of people don't take this into account when calculating stat priorities! Each Crit does 150% damage instead of 200%, and there is only one chance at a 30% MS instead of two chances. This also applies to heals!

Taking the nerfs into account, let's do an average damage increase you would get from each stat if you stacked 1000 rating worth. I will not account for burstiness here, because getting a string of lucky crits of multistrikes can always happen, but it will even out in the end, and you don't want to rely on pure luck to win arena matches.

**Haste (11.2% (given infinite uptime) DPS increase per 1000 rating points):**

Haste is pretty good, and was recently buffed.

As Unholy, when sitting in Unholy presence, you get a 20% bonus to all Haste you equip. Furthermore, we have an additional 5% Haste added from Unholy Aura.

Therefore

**all haste you equip is getting multiplied by 1.20*1.05 = 1.26**

This is not as much as frost gets, but it's still worth noting.

1000 Haste rating / 90 pts per % rating * 1.26% extra for Unholy DKs = 14% Haste

However, since 15-35% (let's say 20% on avg) of our damage is from Diseases, Haste is really only giving 14%*0.8 = 11.2% DPS increase.

- 14% haste means 14% faster attack speed, which means 14% more auto-attack damage (**).
- 14% haste also means 14% more Sudden Doom procs (**) due to increased attack speed.
- 14% haste also means 14% faster rune regeneration (**), meaning that (for ex) over 100 seconds, a rune would fully cycle 11 times instead of 10 if you depleted it instantly every time it came back.
- Haste increases Ghoul attack speed(**) and Gargoyle attack speed(**).
- Haste means more runic power and more Sudden Doom procs, therefore more Deathcoils and thus lower cooldown on Dark Transformation.
- Because of higher rune availability, Haste provides some utility letting you purge with Icy Touch (needed by Unholy since Frost gets free Rime procs), Death Strike more to keep yourself up, and Chains of Ice more often.
- Unholy's DPS starts out rather slow due to the Frost and Blood runes which have to be converted to Death before they can be used to spam Scourge Strike. Haste will help with this, letting you cycle your runes into Death Runes faster.
- Haste does NOT affect the GCD because it's already capped at 1 second (**).
- Haste does NOT affect any of our diseases (**).
- Haste does NOT affect Conversion, or Breath of Sindragosa (BoS), or any skill that says it ticks "every X seconds".

- Haste does not fully kick in immediately once you start attacking. At first you will get faster auto-attacks, so about 2.6-3 seconds after you attack, you will get a second auto-attack that will be sooner with more haste. But after that, it will take around 7 seconds for runes to start coming back due to higher haste.
- Haste does not affect diseases. From my tests, as well as info others have submitted, diseases seem to compose anywhere from 15 to 35% of our damage, depending how many targets they are on. Necrotic plague especially tends to contribute a lot as Unholy.
- Haste does not affect the GCD.
- Haste does not affect Breath of Sindragosa while it's up, so it will not make it burst faster. However, it will make your runes come back faster, which might allow BoS to stay up longer (?) due to the extra runic power you will have.
- Haste can at most affect the recharge of 3 runes simultaneously. If you don't have one rune of each type depleted, then Haste's contribution is being reduced. If you have 2 runes recharging, then you're getting 66.7% of Haste's effect. One rune is 33.3% etc.
- For Unholy, Haste is already very high due to Unholy Presence. As a result, you will find yourself in more situations where you are sitting on 4+ runes and be unable to unload them into damage fast enough because Scourge Strike only consumes one rune at a time.
- There is concern that there's such thing as too much haste. For Frost I showed this isn't really possible, but for Unholy it feels like there is such a threshold. As you get over 40% Haste, you will start to notice that you can't unload your runes fast enough and you sit on 4+ runes sometimes as you try and burst targets. This happens primarily because Unholy has to spam Scourge Strike to burst, but Scourge Strike only uses 1 rune, so it takes 6 GCDs to empty all your runes. Rune recharge time is less than 7 seconds, so you are almost in a situation where you cant spend the runes fast enough.

**Crit (4.54% DPS increase per 1000 rating points):**

Crit is the worst stat for Unholy, just as it was the worst stat for Frost, but this time it's because MS is slightly better for Unholy.

1000 rating / 110 rating per % = 9.09 Crit chance for 1000 rating.

So we are adding a 9.09% chance to do 50% additional damage, meaning on every attack that can crit we are adding 4.545% damage.

- Diseases can Crit! Actually all damage a DK does can Crit! (*)
- That's it...Crit doesn't have any other perks.

**Multistrike (~6.54% DPS increase per 1000 rating points):**

As Blizzard themselves have said, Crit and MS are equal, even in PvP.

1000 rating / 66 rating per % = 15.15% MS chance for 1000 rating.

So we are adding an 15.15% chance to do 30% additional damage, so by simple math: 15.15% * 30% = 4.545% damage increase.

However, because of the Necrosis passive, MS does a little more. Much to my dismay,

**even though Necrosis says you get 5% more MS from all sources, it doesn't work(**)**. I think that part of the passive is bugged and I have reported it. Still, there is a small buff in the form of some shadow damage whenever you MS using some rune-consuming abilities.

The contribution of Necrosis is a pain to calculate, but from the data I have collected and received from others, it amounts to at most 2% damage increase when you have ~15% MS. This means that we can add 2% to our 4.54% and get 6.54% DPS increase best case.

As you will see in the stat priorities, the actual number doesn't matter, it's just to show that MS is better than Crit.

- Every attack can MS, including diseases. I am not sure if Death Strike healing can MS (?), but I am sure that Conversion cannot(**).
- Multistrikes can crit!
- Necrosis adds a small amount of shadow damage whenever you get an MS off some rune-consuming abilities like Scourge Strike, Reaper, Festering Strike, Plague Strike.
- I see some sites saying MS is the best stat, but I just don't see it in the math; far from it in fact. Maybe they are forgetting it only procs once in PvP?

**Mastery (~12.5% DPS increase per 1000 rating points):**

Everyone probably madly scrolled down here to see if the previous predictions were correct. Well worry not, they are!

1000 rating / 44 rating per % = 22.73% Mastery for 1000 rating.

- This means 22.73% increased Shadow/Plague/Shadowfrost damage (**). But how much of our damage is this actually?
- According to my tests, I get between 50-60% Shadow damage (when doing regular dps).
- So therefore 22.73% * 55% = ~12.5% damage increase per 1000 Mastery. This easily beats all the other stats in terms of raw damage.
- Mastery increases Scourge Strike, Death Coil, Necrotic Plague, and Gargoyle damage. Basically all your best burst is increased by Mastery.

**Versatility (7.69% DPS increase per 1000 rating points):**

This is the easiest one to calculate. This is a great stat because it offers healing and defense bonuses.

1000 rating / 130 rating per % = 7.69% Versatility for 1000 rating.

- 7.69% Versatility means 7.69% more damage across the board on all damage DKs do (*).
- 7.69% Versatility means 7.69% more healing on Deathstrike, and other heals that are not %life based. Versatility does not increase Conversion healing!(**) Death Pact (?)
- 7.69% Versatility also means 3.85% less damage taken from all sources (*).

**Some ugly facts I found while testing:**

- The 5% bonus to MS supposedly given by Necrosis doesn't work.
- The PvP target dummy at the Glad Sanctum takes double damage from crits instead of 50% more - probably a bug. Multistrikes are also causing 2 strikes instead of 1.

**Strength:**

I didn't test anything for Strength, but it almost never overlaps with secondary stats, so not much to discuss here. Even if it does, Str gets so many insane %-based bonuses from DK passives and procs that it easily outdoes the other stats (*).

**Putting it all together:**

- All the numbers are for 1000 rating in isolation. Some may wonder if it changes when you throw all the stats together and in different amounts. I would say that in most cases it does not because stats do not interact in any way that provides a faster or slower damage increase than each stat would on its own.
- Strengh is most likely the best stat in all cases, unless someone can prove otherwise.
- Mastery is easily the best secondary stat. It affects all our best burst, all the time.
- Given that Mastery is the best stat by a long shot, and that many PvP items come in a MA/something flavor, gearing basically comes down to choosing all the MA items (but making sure to get the 4pc bonus). So the rest of the stat prio is somewhat irrelevant.
- An added note on Mastery vs Versatility: The dps gap between Mastery and Versatility decreases linearly as MA and Vers values increase. Eventually, at around 6000 Mastery and 2000 Versatility they become equal, and after that Vers is better. So you essentially get some diminishing returns if you constantly choose MA over Vers at high levels of MA. That said, at the levels of gear we currently have you will only experience a decrease of about 33% if you run the gear recommendations below. The reason I'm raising this point is that if you feel too squishy (which you may feel as unholy), feel free to switch some enchants to Vers.
- Haste and Versatility are both really good. For Unholy however, I would take Vers because Haste is already super high and you will likely be wasting its effects because Unholy often sits on several runes while trying to dump Scourge Strikes.
- Crit is the worst from the numbers.
- MS is interesting due to Necrosis, but because it only adds damage if the MS came from a limited set of rune abilities, its overall DPS contribution is very low. Many people expected MS to be higher up I think, but the PvP nerfs are just too much and Necrosis doesn't trigger from enough sources to make up for it.
- If we compare MS and Vers, the damage numbers are close, but Vers has the damage reduction advantage, and has no RNG component so it will perform better overall.

**Stat Priority:**

So the stat prio in my opinion is ('>>' means much better):

**Str >> MA > Vers >**

**Haste > MS >> Crit**

**Gear Selection:**

Here is my best attempt at putting together a gearset that satisfies the above. I would take the 4pc set bonus here, even though you sacrifice some stats. The 4pc bonus is basically another trinket on a 45-60 sec cooldown depending on how often you can Death Coil, so it's just too good to pass up.

**NOTE**: Some Vers pieces require Revered with the Ashran faction. This might seem annoying, but it's actually extremely easy. Go to Ashran, but don't group into a raid. Run solo, and loot as many enemy corpses as possible. Occasionally you will get a blue item that you can hand in at your home base for 2750 rep. I got to revered in 1 hour doing this.

Helm: MA/Crit Set Piece

Chest: MA/Vers

Shoulders: MS/MA Set Piece

Gloves: Crit/Haste Set Piece

Legs: MA/Haste Set Piece

Boots: MA/MS

Belt: MA/Vers

Bracer: MA/Haste

Neck: MA/Crit

Cloak: MA/Haste

Ring1: MA/Crit

Ring2: MS/Haste. Legendary ring doesn't proc in arenas or rbgs.

Trinket1: Vers with proc Str

Trinket2: Str with on use Vers (Don't get the Mastery trinket because Str is better)

Enchants: Mastery

Final projected bonuses:

+5.8% MS

+43.6% MA

+3.2% Vers

+6.9% Crit

+9.7% Haste