Hey guys,

I figured noone did any theory crafting on Mastery compared to other stats yet, so I thought why wouldn't I give it a try.


I started with deriving the formula's for a single Corruption, UA, Bane of Doom, Drain Life and Shadow Bolt tick(or hit in the case of Shadow Bolt), on the PTR. Taking in to account the new multipliers involved, aswell as mastery, crit, haste and spell power.

Having done that, I know was able to compute this into a formula for the dps of such a spell, taking in to account the time between every tick and it's scaling with Haste as such.

After this, I inserted a lot of different values in to the formula(using Excel) and so far I've come up with four graphs, that I think everyone will find the most interesting.

For both UA and Corruption, I've compared Mastery against Haste and Mastery against Spell power.

The benchmark stats used were:
3500 SP
800 Haste Rating
400 Crit Rating
0 Mastery rating(Inititally).

I've compared the stats, by looking at the change in the dps, when simultaneously reducing Haste or Spellpower by 10, while also increasing Mastery rating by 10(Since all these stats now have the same item budget).

The following graphs were the result:










The X-axis, represents the increase in Mastery(while simultaneously reducing either Haste or Spellpower) and the Y-axis is the dps UA or Corruption will then do.


Note:
This "analysis" was done with regard to patch 4.0, for those long months between the end of the arena season and Cataclysm. At the same time, I also hope it provides some insight on the value of Mastery.

Conclusion:

Blizzard has done a amazing job with Mastery. No longer is it possible to just stack one stat and know it'll give you the most dps. No, it would appear that you actually need to combine different stats properly for the most effect.

As you can see in the graphs, for most of us it'll be worth sacrificing a bit of Haste for Mastery, in terms of raw damage.
However, at our current level of Spellpower, we shouldn't sacrifice any for Mastery.(I have noticed, that once your spell power nears a point around 5700, Mastery might be point for point better than it, but it's too soon to tell.)

So my advice to you guys would be, once 4.0 comes and assuming you care about this period before Cataclysm, you should definitely use the reforging option, to change all the crit you can into Haste, aswell as all the Haste you can.

As far as I can tell, the sweet spot will be(again in terms of raw dps) around 500 Haste, changing all additional Haste in to Mastery.


Right, that concludes my post, I hope it has been of any use to you guys.

Ps. If there's a particular thing you're wondering about with regards to anything related to the above, feel free to ask(I'm not in the Beta though, so I can't check on anything there).

For those interested, the formulas I derived:

For UA: ((1-%crit/100)*(108,344+0,2044*Spellpower)*(1,1304+0,0163*Ma stery points)*1,25*1,15*1,2)/(3/(1+Haste%/100)))+2*((%crit/100)*(108,344+0,2044*Spellpower)*(1,1304+0,0163*Ma stery Points)*1,25*1,15*1,2)/(3/(1+Haste%/100)))

For Corruption:
((1-%crit/100)*(165,69+0,22*Spellpower)*(1,1304+0,0163*Maste ry points)*1,25*1,15*1,2*1,12)/(3/(1+Haste%/100)))+2*((%crit/100)*(165,69+0,22*Spellpower)*(1,1304+0,0163*Maste ry Points)*1,25*1,15*1,2*1,12)/(3/(1+Haste%/100)))

I realize these formules could be simplified greatly by rewriting them, but luckily to use them in Excel I didn't have to.

Some clarifications for these formulas: The (1-%crit/100) and 2*(%crit/100) parts of the formula, are used to also take in to consideration crit ratio's, and the double damage a spell then does.
(1,1304+0,0163*Mastery Point) is the bonus your spells get from Mastery.
The *1,25*1,15*1,2*1,12 for Corruption, are the multipliers for Corruption, being Haunt, SE, 25% from Shadow Mastery, and 12% from imp Corruption. The same apply to UA, except ofcourse for imp Corruption.
Also note that these formulas are meant to calculate the Damage per second of the spells, and as such I also had to involve Haste and the time between each tick, as shown by the /(3/(1+Haste%/100)) parts.