I am not a theorycrafter really. I have a basic idea of how the stats work for the classes, and why we want some more than others, but I couldn’t tell you the exact values, or how people determine them, or even a vague idea of how people decide how to determine stat weights. All that having been said, I do want to talk about Death Knight stats for a few minutes. Basically, I am going to go down the line and list what each stat does for us (for each spec), why we would want it, and why we would not want it. I’ve noticed a rather disheartening trend among all of the so-called “guide” sites (noxxic, mr robot, EJ, icy-veins) in that NOBODY is giving the same information to the community. This is a problem because if 4 people are getting their information from any of the 4 different sites, who’s to say who’s wrong or right?
Strength: Initially, I wasn’t going to mention it, but I feel the need to do so because I *still* come across some numbskull DKs rolling on Agility rings or trinkets or what have you. Strength is our base stat. Long gone are the days of DKs using agility weapons, because we get absolute shit for benefit from them. If a DK is using an agility weapon, they’re doing it wrong. Some people have the sort of “golden rule” about a 3-tier improvement making agi weapons allowable based solely on weapon damage increases alone, but I think that’s shit. If you’re a DK, you should have strength on everything. All three specs get 2 AP (Attack Power) per 1 point of strength.
Blood – Blood DKs get an added bonus of having a parry rate conversion from strength. Roughly 90% of strength is converted into parry rating. To put this into easier-to-digest terms, if an item has 100 strength on it, and you’re a blood DK, it’ll give you the equivalent of 90 parry rating as well.
Hit: This is a simple one to explain. Hit lets you hit things more frequently. Easy, right? The percentage to never miss a raid boss-level mob is 7.5% (2550 hit rating at 90, or 2210 hit rating if you’re a draenei)
Frost Dual-Wield – Any dual-wielding class has things a bit differently. They will notice two sets of hit ratings on their character sheet when they mouse over it. Innately, it takes something like 15% hit rating to completely hit cap (aka “white cap”. Every attack that has white damage numbers is an auto-attack, whereas if it’s yellow numbers, it’s an ability). It’s worth noting that NO dual-wielding class will pour enough stats into reaching white cap. They will stop at 7.5% (“yellow cap”, or “specials cap”). The amount of hit rating it takes to white cap simply take too much away from the your other stats to be worthwhile.
Expertise: This one is relatively simple to explain as well. Every creature in wow (player-controlled or NPC) has a built-in chance to dodge attacks, and most have a chance to parry them as well (not all PCs do). Expertise removes the chance you will be dodged or parried (in that order). Now, prior to MoP, expertise was handled a bit differently in that up to a certain point, it would push some of both dodge AND parry off the table. Since 5.0, it is much more simply done. There is a maximum of 15% expertise. 7.5% (2550 hit rating at 90, or 2210 hit rating if you’re a have sword/axe/mace specialization and are using the corresponding weapon) will completely push dodge off the combat table, and the next 7.5% will push parry off the table.
Frost/Unholy – It’s worth noting that NO creatures can parry from the back or sides. If you are frost or unholy (or any other melee dps class for that matter), you should *always* be behind the boss whenever physically possible. Since you’re ideally behind everybody, you never have to worry about parry, so you can safely stop at 7.5% expertise.
Blood – Now then, obviously tanks don’t get that choice. They’re always in front of the boss, and as such will get parried sometimes. With this in mind, as a tank, you’re probably NEVER going to go for the 15% expertise level. The reason for this is because Death Strike cannot be parried. Basically, the most important ability that factors in your survival stops at 7.5% expertise, so why go higher?
Haste: Haste is a funny thing for Death Knights. Actually, it’s been a funny thing for a lot of classes since 5.0, but that’s not what i’m writing about. Haste makes our weapon swing faster, that’s the obvious part. Haste also plays a part in our rune regeneration, so it’s something that has the potential to be a big deal for all of the specs.
Frost 2-handed/Unholy - Haste is the biggest stat for 2-handers. Because of the way things work currently, haste will contribute more runes for you to hit the big button (either obliterate or scourge strike) more often. It also contributes more, proportionally, to your swing speed since you start off with a much slower speed.
Frost Dual-Wield - Prior to 5.0, haste was the big deal for all three DPS specs, but it doesn’t work like that anymore… more on that later.
Mastery: Mastery continues to be an interesting stat to look at across the board for all three specs of Death Knight.
Blood – Mastery is the king of the frickin hill for tanks. Death Strike is your mainstay of survivability, and mastery increases the percentage of your death strike that gets turned into a shield. For instance, i’m currently sitting at about 130% mastery, so to put it in easier to digest numbers… if my DS heals me for 10,000 then I will generate a shield for 13,000.
Unholy – Sadly, mastery is kind of the bottom of the heap for unholy specced DKs, and i’ll tell you why. Haste not only contributes to your swing speed and rune regeneration, but it ALSO contributes to your minion’s swing speed. It double dips, sort of. Crit has the same thing in that it increases your crit, as well as your ghoul’s crit. Mastery increases shadow damage, and while a significant portion of YOUR damage is shadow damage, your minion does NOT deal shadow damage.
Frost - Frost is a funny thing. If you are a dual-wielding frost DK, then mastery is going to be your kingpin. With Frost Strike being your heavy hitter (and dealing actual FROST damage instead of weapon damage like Obliterate), then mastery just makes your hardest hitter… hit harder. Conversely, for the 2-handed frosty DKs, frost strike is a much lower portion of your damage overall, so you don’t benefit as much from mastery.
Crit: Crit is, by and large, a pretty simple stat that is worthless to 3/4 of the Death Knight specs.
Unholy – As I mentioned before, Unholy is the only spec that really gets any actual benefit from crit. It’s not a strong a stat for you as haste is, but it IS stronger than Mastery in that your minion will double dip from any extra crit you already have. It’s relatively useless for Frost because most of your crits are going to come from Killing Machine procs, and it’s even more useless for Blood because your job is staying alive, not putting out big numbers… although we ALL KNOW that you’re tending to do both right now. So why do you need crit anyway, huh? Greedy.
Dodge/Parry: This is only going to be found on tank gear. If you’re an unholy or frost DK, and you have either of these on your gear, then you are doing it WRONG.
Now then, to break it down, the varied specs stat priorities SHOULD look like this.
Blood – Hit/Exp cap* > Mastery > Parry** > Dodge > crit/haste.
*I know that in a previous post I said that 7.5% hit/exp may not be the best way to go for raiding, and in fact I still stand by that feeling. However, to be completely optimal, you DO want to eliminate all chance for death strike to miss, so 7.5% hit and 7.5% expertise is the OPTIMAL way to go, but between 4-5% of each is definitely satisfactory.
**As it stands currently, Parry is more valued than dodge because we have a higher value of baseline dodge (with zero gear on). About twice as much, actually. That in mind, we want to have about twice as much parry as we do dodge, because it will take that much more for the diminishing returns to even out. It’s also worth noting that the 4% parry given from Rune of Swordshattering does NOT SUFFER from diminishing returns… it’s a free 4%.
Frost 2-handed – Hit/Exp cap > Haste > Mastery > Crit
Frost Dual-Wield – Hit/Exp cap > Mastery > Haste > Crit
Unholy – Hit/Exp cap > Haste > Crit > Mastery
It should be noted that these priorities COULD be wrong. They are based on what I know and understand about the various specs with my own personal experience, but I have no math to back them up because… well, honestly i’m not very good with the maths. I don’t have stat weights for any of these. They are just “X is better than Y” in black and white, because that’s generally how it works.