Please note, this guide is not an all-inclusive raiding guide. It focuses specifically on affliction, due to the fact that affliction rotations are particularly difficult. This thread dissects all information regarding just this aspect of raiding. This is not a spec, glyph, etc guide.

I. Intro
II. DPCT
III. Sample Math
IV. Rotations
V. WWS and DoT Uptime
VI. Practice Tips


I. Intro
The thread here is about Affliction Rotations. This will answer very common questions such as these: Should I use immolate? Should I drop any DoTs from my rotation? What is the rotation? My DPS is really bad, what am I doing wrong? How can I get better at affliction? This will be broken up into 2 posts. The first, below, dealing with DPCTs and whether or not you should be casting all of your DoTs.

I'll start by clarifying what DoTs should be used. The answer simply is, ALL of them. This includes immolate! Affliction is all about efficient use of the Global Cooldown or GCD. If you're not constantly casting something, then you're losing DPS. This is true with any spec reall, but with affliction, that loss is more noticable. Because affliction is so dependent upon efficient GCD usage, one of the most important things to know for any affliction warlock is called DPCT. (Damage Per Cast Time)

II. DPCT
DPCT is a measure of what you get in damage return for the amount of time used to cast a spell. For example. If you cast a shadowbolt, and your shadowbolt's average damage is 1000, with a 2.5 second cast time, the DPCT is 1000/2.5 or 400DPCT. If you cast a DoT that will do 1000 damage (no matter how long it takes to do that damage), and the DoT is instant cast, then the DPCT is 1000/1.5 or ~667DPCT. (Instant casts "time used casting" is whatever the length of your global cooldown is.)

So, what does this mean to an affliction warlock? Simple. Shadowbolt is your "filler" spell. IE, it's what you cast when your dots are ticking and none of them need refreshing. You fill this gap with shadowbolts. That said, any dot that has a higher DPCT than your filler spell (shadowbolt) should be cast, because it will mean more dps for you. This is because you get more damage for the amount of time spent casting the spell than you would casting a shadowbolt.

III. Sample Math
Below, I have listed out the DPCT for all of an affliction warlock's spells, using (22% crit from gear) 40% crit rating, 2000 spell power, and hit capped. This assumes a 56/0/15 build, and the stats are AFTER raid buffs have been applied. (build: Talent Calculator - World of Warcraft)

Corruption:
1080 base damage + ((120% coefficient + 36% empowered corruption + 30% everlasting affliction) * 2000) =
1080 + (1.86 * 2000) = 4800 base damage.
Modifiers:
4800 * (10% improved corruption + 15% shadow mastery + 5% contagion) * 3% malediction * 13% earth and moon * 3% sanctified retribution (ret pally) * 20% haunt * 10% shadow embrace =
4800 * 1.30 * 1.03 * 1.13 * 1.03 * 1.20 * 1.10 = 9874 modified damage.
Pandemic: 9874 * 1.22 = 12046
12046 / 1.5 second GCD = 8031DPCT

Curse of Agony:
1740 base damage + (120% coefficient * 2000) =
1740 + (1.20 * 2000) = 4140 base damage.
Modifiers:
4140 * (10% improved CoA + 15% shadow mastery + 5% contagion) * 3% malediction * 13% earth and moon * 3% sanctified retribution (ret pally) * 20% haunt * 10% shadow embrace =
4140 * 1.30 * 1.03 * 1.13 * 1.03 * 1.20 * 1.10 = 8516 modified damage.
8516 / 1.0 second GCD (amplify curse) = 8516DPCT

Immolate:
(460 base DD damage + (20% coefficient * 2000)) + (785 base DoT damage + (100% coefficient * 2000)) =
860 base DD damage + 2785 base DoT damage
Modifiers:
860 base DD damage * 3% malediction * 13% earth and moon * 3% sanctified retribution (ret pally) = 1031 modified DD damage.
(crit factor) 1031 modified DD damage * 1.40% = 1443 total DD damage.

2785 base DoT damage * 3% malediction * 13% earth and moon * 3% sanctified retribution (ret pally) * 20% haunt * 10% shadow embrace = 4407 modified DoT damage.

1443 DD + 4407 DoT = 5850 total damage.
5850 / 1.5 second cast time = 3900DPCT

Siphon Life:
810 base damage + ((100% coefficient + 50% everlasting affliction) * 2000) =
810 + (1.50 * 2000) = 3810 base damage.
Modifiers:
3810 * 15% shadow mastery * 3% malediction * 13% earth and moon * 3% sanctified retribution (ret pally) * 20% haunt * 10% shadow embrace =
3810 * 1.15 * 1.03 * 1.13 * 1.03 * 1.20 * 1.10 = 6933 modified damage.
6933 / 1.5 second GCD = 4622DPCT

Unstable Affliction:
1150 base damage + ((100% coefficient + 25% everlasting affliction) * 2000) =
1150 + (1.25 * 2000) = 3650 base damage.
Modifiers:
3650 * 15% shadow mastery * 3% malediction * 13% earth and moon * 3% sanctified retribution (ret pally) * 20% haunt * 10% shadow embrace =
3650 * 1.15 * 1.03 * 1.13 * 1.03 * 1.20 * 1.10 = 6642 modified damage.
Pandemic = 6642 * 1.22 = 8103
8103 / 1.5 second GCD = 5402DPCT

And finally,
Shadow Bolt:
730 avg base damage + (85.7% coefficient * 2000) =
730 + (.857 * 2000) = 2444 base damage
Modifiers:
2444 base damage * 15% shadow mastery * 3% malediction * 13% earth and moon * 3% sanctified retribution (ret pally) = 3369 modified damage.
ISB factor = 3369 * 1.085 = 3655. (this assumes 85% uptime which is inline with 40% crit rate)
(crit factor) 3655 modified DD damage * 40.0% = 5117 total DD damage.
5117 / 2.5 second cast time = 2046DPCT

So, as you can see, ALL of your DoTs should be cast. You can use the above formulas to plug in your own stats, including haste, crit, and spell power. For crit, without ruin, you simply cut your crit rating in half, and insert that % into the above formulas. For haste, simply change the cast time to match your cast time.

One exception to the above is that you can consider dropping immolate from your rotation once Death's Embrace kicks in since it boosts all of your shadow damage considerably.

IV. Rotations
Up next, it's time to talk about rotations, and how to raid with affliction. This will also include a section on how to run a WWS parse, and calculate your DoT uptime.

Let's start with what's normally called the "rotation". Rotation is not really an appropriate name, since after the initial casting of each DoT, you'll pretty much never cast them all in the same order again, due to the fact most of them have different durations.

Always start with a shadowbolt, and then haunt. Now, many people often ask why you would do this, and some people are even under the misconception that casting haunt after your DoTs is somehow more efficient. Think about it this way: Haunt should have 100% uptime for the entire fight. And since DoTs receive the bonus no matter when the debuff went up (before the DoT was cast, after the DoT was cast, makes no difference), it only matters that the debuff is up. So, why would you cast DoTs first, and have the first several ticks not get any benefit from Haunt? If you're going to have Haunt up the entire fight anyways, wouldn't it be better to have ALL ticks benefit from Haunt? Of course. The same goes for shadow embrace. The first stack is put on by that shadowbolt, and the second stack by Haunt.

So, your intial cast rotation will look like this:

Shadowbolt > Haunt > UA > Immolate > CoA > Corruption > Siphon Life. After that, you're now into what is called "filler" time. If your raid does NOT have a moonkin druid or unholy death knight, you will use CoE for your curse instead.

From this point on, your goal is to refresh DoTs as efficiently and quickly as possible. I HIGHLY recommend Asheyla's DoTimer. It is a great mod for tracking your DoT durations. You can get it here: DoTimer : WoWInterface Downloads : Warlock

The goal is to refresh a DoT the very moment the last tick expires. For DoT's with cast times, this is done by starting to re-cast the DoT when the amount of time it has left is just slightly less than the DoTs cast time. For example. If your Unstable Affliction has a 1.5 second cast time, you start to cast a new UA when the current one has 1.4 seconds left on the timer. Now, being realistic, obviously it's rare that this will happen. The reason for that is you do NOT want to stand around doing nothing just because you're waiting for that timer to hit 1.4 seconds. It is better to do something, whether that's casting a shadowbolt or using dark pact / life tap. Even if it means you will be a bit "late" refreshing the DoT.

Generally, you do not want to "clip" a DoT. This means refreshing the DoT before the previous one had its last tick of damage go off. And since Corruption is automatically refreshed by Haunt via Everlasting Affliction, you never have to worry about corruption.

Next, there is a reason we cast UA and Immolate together. They both have a 15 second duration, therefore every successive refreshing of these 2 DoTs will always be UA and then Immolate immediately following. You can essentially think of them as just one dot with a 3 second cast time.

And finally, since haunt has a 12 second duration, and you start with Haunt, then UA, and immolate, eventually haunt will work its way around and end up right after you refresh UA and Immolate. When this happens, on the very next "refresh", refresh Haunt early, allowing you to reset the rotation back to Haunt, then UA, then Immolate. So for example, with about 2.9 seconds left on UA's duration, cast Haunt. This brings you to 1.4 seconds left on UA's duration, so you immediately follow Haunt with UA, and then of course immediately again with Immolate.

Lastly, never interrupt a spell cast mid-cast just so you can cast something else. You want to try and avoid that whenever possible.

V. WWS and DoT Uptime
Now that you have the basics of DoT casting order, rotations, etc, let's work on applying that, practicing, and seeing results for yourself.

To start, a quick explanation of WWS (wow web stats). WWS is an online DPS parser. It takes a combat log you record in game, and allows you to see the information in a very useful and detailed format. To create a WWS report:

1. Before you start WoW, browse to C:\Program Files\World of Warcraft\Interface\Logs. If you have a file called "wowcombatlog.txt", delete it!
2. Now, in game, before you start whatever it is you want to log, hit enter in your chat window and type: /combatlog (this will get wow recording your combat log parse)
3. After you are done with everything you want to record, go to Wow Web Stats
4. Click on "Start WWS Client" (note, you may have to quickly sign up for a free account)
5. Click on "Add Combat Log" and browse to C:\Program Files\World of Warcraft\Interface\Logs, and add wowcombatlog.txt.
6. Click on "Host Report". You will now see a WWS report of your combat log!

The sample below references one of my WWS reports, but can be applied to any WWS report you use.

Let's figure out doT uptime first. To start, we need to know what the total combat length of the boss fight was in seconds. At the top of a WWS report, you'll see the date, time, and length of fight in minutes/seconds. In my example, the fight was 2 minutes and 39 seconds long. So, that's 159 seconds.

Next, we need to determine what 100% uptime would be for each DoT. This is done by taking the length of the fight and dividing it by the interval of a DoT's tick. For example, corruption, UA, siphon life, and immolate all tick every 3 seconds. 159 / 3 = 53. So, if I had 53 ticks of each of those DoTs, that would be 100% uptime. To see how many times your DoTs ticked, look under each spell, and look under the column that says "Dots".

In my example, I had as follows:
-Corruption: 48 ticks
-UA: 42 ticks
-Immolate: 39 ticks
-Siphon Life: 46 ticks

Remember that 100% uptime is not realistic. Especially if the mechanics of the fight stress execution over DPS via moving around, doing other things, etc.

For CoA, which ticks every 2 seconds, that would be 159 / 2 = 79 (round down). I had 68 ticks, so that's not too bad. To determine uptime, take the number of ticks you had and divide it by the number of ticks you would have had with 100% uptime. So, for CoA: 68/79 = .86 or, 86% uptime. 90% uptime is a realistic goal in a stand-up tank and spank single target fight.

VI. Practice Tips
If you're struggling with DoT uptime, start by simplifying the rotations by temporarily dropping a DoT. Drop siphon life and CoA. Then, practice, and get that rotation down and working. Then, add in Curse of Doom. Practice more! Then, add in Siphon life. Practice practice practice. Now finally, replace Curse of Doom with Curse of Agony again.


I am open to all suggestions, corrections, and advice that others may have. Please post them for discussion!



Special note about imp vs felhunter:
There's a big caveat with this. Technically, the felhunter is actually more dps. On beta we were seeing him do 100+ more dps than the imp for affliction builds. However, currently both pets are bugged. The imp's mana regen is 2-3 times higher than it should be while casting or in combat. So, the imp never goes OOM. But if I recall, on beta he'd go OOM for an afflock after about 3-3.5 minutes.

Also, the felhunter currently bugs out and stops attacking randomly during fights. So it makes it look like he's doing less dps than he really should be.


So, for now, yes use the imp. But both bugs have been reported, so I would assume that the felhunter will reclaim his throne once the bugs are fixed.

I only have 1 question. I've always been putting up corruption as the very first thing I do, then a haunt and shadowbolt. You say that it is more efficient to have the haunt and shadow embrace buff up first, before any ticks of DoTs go off. However, in doing so don't you lose one tick of corruption? Casting haunt and shadowbolt even after haste, uses more than 3 seconds of cast time, which could have been used to gain an extra tick of corruption. Assuming you're fairly close to the mob, so there is little travel time, you could theoretically have your first tick still have the haunt and 1 stack of shadow embrace buffs.
Example:
with 20% haste (easily attainable raid buffed) your GCD and Haunt cast times are both 1.25s. Corruption ticks after 3.
So if you open with corruption:
0s:Corruption
1.25s:Haunt starts
2.5s: Haunt cast finishes, you have .5s for travel time.
3s: Corruption ticks
4.5s: Shadowbolt finishes
6s: Corruption ticks

So in the first 6 seconds youve done haunt damage, Sbolt damage, and 2 ticks of Corruption with haunt and 1/2 for the first, 2/2 for the second stacks of Shadow Embrace. All following dots will have full benefit of both haunt and Shadow embrace.

If you were to cast Sbolt/Haunt first:
0s:Haunt
1.25s:Shadowbolt
3.3s:Corruption
4.5s:GCD finishes
6.3s:Corruption ticks

Casting Sbolt / Haunt first, you're not getting any DoT ticks until over 6 seconds into the fight, whereas casting corruption first you gain an extra tick. Even if due to lag/travel time the first tick of coruption doesn't get the buffs, I still dont see how it could be a DPS loss casting it first.

Ah, but, you're forgetting that I can start the first cast of my shadowbolt a bit sooner than you would start by casting corruption. In your example above, if you were to pit the two in a timeline against each other, your rotation would be corruption at 0 seconds. Mine would actually start with shadowbolt at -2.0 seconds compared to your corruption at 0 seconds. You can do this with my rotation since shadowbolt has a longer cast time. Either way you don't want any spell landing (damage or not) until the tank has initial aggro. So, if you time it accordingly, you can make shadowbolt land at the same time in the timeline as you'd be casting corruption.


So, my timeline would be:

-2.0s:Shadowbolt
0s:Haunt
1.25s:Corruption
4.25s:Corruption ticks


And so on. So, because I timed it correctly, I actually did SB, haunt, and 1 corruption tick with the full benefit of 2x SE and haunt, all in the first 4.25 seconds, compared to your rotation taking 5 seconds to do the same, but with your first corruption tick not getting the 2nd stack of SE.

I did notice in 25 man Naxx last night that my felhunter never ran low/out of mana. I do not have dark pact (55/0/16 at current.. took 1 out of improved fel hunter for molten core). Perhaps that 1 point in fel hunter could have a better place.

There are also a few things I was not as pleased about the spec
1. the loss of the +6 yard range to all your nukes
2. loss of dark pact (more for when tapping for 3100 life is just not too safe)

The problem is I can't find too many points that can be subbed out
all of the talent points add to your dps in one way or another.. but I am curious which one's add the least
possibly 2/3 eradication will serve almost as good as 3/3
maybe 2/2 nightfall is not as big of a boost

I guess trying to get as much damage as possible comes at a price

Yeah, you don't need improved felhunter. Though, one thing I should mention is that the felhunter also isn't using as much mana as he should be, as he currently sometimes "bugs out" and stops attacking altogether. I reported this as a bug on the wow forums, so hopefully it gets looked at soon.

I have not had any issues with range using any spec that didn't have the range talents. It really doesn't seem to be a problem for me. As for life tapping VS dark pact, you really should not ever have to worry about tapping, though obviously you have to make sure you don't tap right before something like decimate on Gluth for example. So, I just plan accordingly for rare instances such as that.

Corruption:
1080 base damage + ((120% coefficient + 36% empowered corruption + 30% everlasting affliction) * 2000) =
1080 + (1.86 * 2000) = 4800 base damage.

This base damage is if he spell runs it's entire course. If there is 3 seconds left on corruption and you cast haunt to refresh the spell is the base damage now reduced to 3840 as you do not get that last tick or does haunt refresh the spell but not the timer. From my tool tip it seems to start a new timer and spell so that 4800 is only 3840. Is this correct?

For the P3 transition I couldn't even get in range while jumping, I was only able to CoE when he blew us all into the air.

I can be reasonably convinced that this is technically correct in some strange point of view, but I cannot be convinced it is relevant. So what if you're refreshing it early? If you refresh corruption without casting corruption, corruption's cast time asymptotically approaches 0, giving it literally infinite DPCT.

An alternate way to view it: Since you're extending corruption as part of a spell you would be casting anyways, you're actually adding 18 seconds to the duration. Despite losing three seconds somewhere, you're still coming out ahead, for 8640 damage off of one cast.


Hrm... are you asking what happens if you refresh corruption half-way through a tick? Everlasting affliction adds duration, it does not reset the tick timer.

Honestly, you shouldn't say 'useless.' Sure, Life Tap returns more mana per GCD than Dark Pact, but Pact still has it's uses. Any fight with a significant amount of raid damage, or strange healing debuffs will have a place for DP. Loatheb and Sapphiron immediately come to mind; there are other fights as well.

Discounting a skill just because it may not be as good as another on paper is pretty foolish; there are a number of situations where DP can prove more useful than LT.

Great post. Never explored the numbers for aflic becuase I always spec'd destro. Did a similar post in my guild forums in BC with destro but now I find myself aflic because my gear didn't scale well with WotLK.

I look forward to bringing immolate in to my rotation. I'm looking at 1 point in molten core and a glyph of imolate to buff immolate dmg further bringing it closer to the DPCT of siphon life.

It's just too bad the the glyph of corruption and nightfall don't proc the instant cast shadow bolt more often. When Shadow bolt is instant cast the DPCT is upped to 3411 making it a very viable filler.

Last thing. I was looking at the numbers for other possible fillers and it made me realize, if you 3 seconds of filler, when the mob is below 25% health, that drain soul has the potential to do more DPCT than shadowbolt, especially because it's listed as periodic damage I believe it to be effected by Haunt and Shadow Embrace. Let me explain.

Drain soul (using the above calculations):
710 base damage + (214.3% coefficient * 2000) =
710 + (2.143 * 2000) = 4996 base damage.
Modifiers:
4996 * 15% shadow mastery * 3% malediction * 13% earth and moon * 3% sanctified retribution (ret pally) * 20% haunt * 10% shadow embrace =
4996 * 1.15 * 1.03 * 1.13 * 1.03 * 1.20 * 1.10 = 9091 modified damage.
9091/5 ticks = 1818.2/tick
1818.2 / 3.0 second tick = 606.1DPCT

Not very viable, but, when the mob is under 25% this spell does 4x the dmg AND I did not include the bonus damage from soul siphon having a 4% bonus per aflic spell up to 60% (requiring 15 aflic spells for full bonus). But, if you are in this situation then we are looking at:

606.1DPCT * 4x dmg (mob <25% health) *60% (15 aflic spells on the target) =
606.1 *4 *1.6 = 3879DPCT

Even with just the 4x dmg bonus for the mob being <25% health puts drain soul at 2424.4DPCT which is 378.4DPCT higher than shadowbolt.

So this thinking also had me look in to Drain Life, another spell listed as periodic damage. Drain life has 1 second ticks but because of a 1.5sec GCD you are best to go 2 ticks before stopping the channeling process to cast another spell.

Drain Life:
665 base damage + (71.43% coefficient * 2000) =
665 + (1.7143 * 2000) = 4093.6 base damage.
Modifiers:
4093.6 * 15% shadow mastery * 3% malediction * 13% earth and moon * 3% sanctified retribution (ret pally) * 20% haunt * 10% shadow embrace =
4093.6 * 1.15 * 1.03 * 1.13 * 1.03 * 1.20 * 1.10 = 7450 modified damage.
7450/5 ticks = 1490/tick
1490/1.5sec GCD = 993DPCT or,
1490*2 ticks/2 sec channel = 1490DPCT

But when you have 60% for soul siphon you will end up (considering the 2 second channel) with 2384DPCT, 338DPCT more than shadowbolt.

Don't forget there's still an addictional 30% dmg from death's embrace if you are below 20% health but how often does that happen?

Bonus's to siphon life = resets corruption timer, and increases chance to proc nightfall which increases the DCPT of shadowbolt by 1365.

Anyways, I love the numbers, I still have some experimenting to do. Thx for the forum to discuss this. I look forward to seeing mre discussion.

But then if you are going to rely on using it, then you need to spec into imp Felhunter as he'll go OOM if you are touching his mana pool during a fight. I'd rather not spec Imp FH and not DP during a fight. Pot/LT as needed has worked though all current raid content w/o fear of dying.

@Beilsibob
Nice to see you enjoying the number crunching and the class. It is widely accepted that you switch your filler to DS @25%. Keeping up Aff spells for buff, dropping Immo basically. People are reporting some incredible tick values also.

Situational use and 'useless' are not the same thing. Simply because you would rather not spec into Imp FH and DP doesn't mean you should pass it off as gospel in your thread.

Improved FH is a nice bonus to a passive raid buff; it results in more spell damage for -all- warlocks in the raid, better mana regeneration for healers, etc. There may also be times where you can't healthstone or chug a health potion - my Loatheb example once again comes to play, as well as the cooldowns on those particular items.

Fair enough that it is 'situational'. But it's a passive raid buff that isn't active if your raid is max/min'd also. I havent seen Fel Intelligence up on my raid since we started doing 25 mans. I also dont know that people are spec'ing into imp FH for the buff to FI, they usually only are for the mana regen for the FH.

Your Loatheb example is fine, but really, I haven't seen my healers have problems keeping the raid up during that encounter yet so I'm life tapping as usual the entire fight. Maybe I'm spoiled with my healers.

Sorry to take this slightly off topic, but back to my original question, what do you mean by starting your first shadowbolt at t = -2? I can't really think of too many situations where you would be able to shadowbolt before being able to cast corruption. On the vast majority of boss fights, you're not going to be able to start in range of the boss so you can begin a shadowbolt before the tank has hit the boss. Most fights you're either going to be running in, or the encounter will start with a Misdirect ect. So how exactly are you casting a shadowbolt before you'd be able to cast corruption? Confused.
On another note, hitting a boss with a Shadowbolt .5 seconds after the tank has picked it up is probably not a great idea.

Can't recall the last time I was in a 25 man raid and didn't have both a mage and a discipline priest ... both of which made the buffs from my fel hunter useless ... and ergo, any points spent in Imp FH would therefore be useless.

At best you can say Imp FH is *highly situational* and more about being asked to spec into it to compensate for your raid composition (or lack thereof).

Saying that "cool downs" or Loatheb are justifications for wasting a Point in DP is not a strong argument at all.

Between SL, Haunt and Fel Armour there are rarely any times when you are out of health AND out of mana AND have both Pot / HS on cooldown AND your pet is still alive to be able to tap from AND you need to run a new string of DoTs.

Even then, what you give up for points are still not justifiable imo. Just because a talent point can help 1 time in 1 situation over the span of a week, doesn't mean it's actually more dps on the majority of fights you will do.

So yes: DP / Imp FH have no place in an standard "End Game AFFLock Raiding" spec imo.

The first thing to hit the boss needs to be the tank right? if the tank is running into pull and you land a dot and the boss veers towards you, generally that is a bad thing. At minimum, you have to wait till an MD lands before you hit the instant cast dot.

Versus, winding up your SB so that it lands right after the MD's go off basically gains you a free SB, as your GDC is UP and you can immediately do that instant cast if you want.

I believe the point was that there are 3 cases (the first of which is very uncommon and potentially a bad idea when it is):
1) Everyone is in range of boss to start and you could precast a Shadow Bolt to land immediately after tank hits it.
2) You run into the encounter, no precasting.
3) The boss is MD'd to the raid, no precasting.

A) #2 is definately one of the times where you don't want to "insta cast" before the tank has established aggro.

B) #3 is getting is not nearly as common as it used to be ... and hunters "running out in front" is even more rare.

#1 and #2 are actually quite common and #3 is becoming the rarity. At least in the 25 man content in LK. I might be spoiled by being in a good guild that tears through stuff :-).

Doing Naxx25 when I get home and I will try to count the number of times of each of the situations.

[quote=Sidewalk;995812]Not sure you can really look at DS as DPCT, especially when comparing it to SB ... and even when comparing, you absolutely can not assume 15 AFF Debuffs. Also, I don't believe the Haunt Bonus applies to DS directly, but I do think it applies via Soul Siphon.[quote]

It's good to see that we have the same numbers and I like yoru spin on the subject. However, in order to standardize the comparison between spells we need to be on the same ground. DPCT was the proposed unit and I went with it. DS needs to be up for 3 seconds in order to tick so hence the 3 second cast time.

I'm more than interested in introducing a new unit but I also like to keep it simple to stop my head from exploding too.

On the other hand, a casted shadowbolt has its threat front-loaded, while a DoT does no damage up front and a debuff Curse has very minimal threat. A shadowbolt can be casting while the tank is building threat, but a DoT can be cast safely literally as soon as the tank touches the mob. Which one gives a longer threat lead depends on how quickly your tank builds threat, but considering most tanks have long-range threat moves nowadays I think corruption is safer before shadowbolt is.

In general, which meta gem would be most beneficial for an affliction warlock? And i guess while we're at it, would it be best to just gem for straight spell damage/spell dmg and haste?

Pure +damage is going to be more beneficial to you than a damage/haste gem. For yellow sockets, if you're going for the bonus, damage/haste or damage/crit is the way to go, if you don't need hit. Otherwise gem for hit, at least to cap your aff spells. Especially if theres a boomkin or shadow priest in your raid, this isn't too difficult.

As for metas, tour main choices are:
Bracing Earthsiege Diamond: +25 Spell Power and 2% Reduced Threat
Chaotic Skyflare Diamond: +21 Critical Strike Rating and +3% Critical Strike Damage
Ember Skyflare Diamond: +25 Spell Power and +2% Intellect
Insightful Earthsiege Diamond: +21 Intellect and chance to restore mana on spellcast
Tireless Skyflare Diamond: + 25 Spell Power and Minor Run Speed Increase

The insightful is going to be the least useful in terms of DPS, I only included it as it could technically be used as a caster DPS meta. For the rest of the options, you esentially have + 25 spell power vs. 21 Critical Strike Rating and +3% Critical Strike Damage. I would assume that the +25 damage metas would be superior, at least for initial t7 levels of gear. This is because the 3% crit bonus is largely wasted on an affliction lock. In a raid situation, Shadow Bolts are comprising roughly 30% of your DPS, and crit about 35%, or about 10.5% of your total DPS. Increasing this fairly small portion of your DPS by 3% would result in a mere .3% increase from the Increases crit damage. The crit rating is about .46%, takin liberally and applied to your entire DPS, this would net a total gain of about .74% DPS gain. 25 spellpower, applies universally across all your spells would probably give a greater benefit. At a raid buffed 2000 spellpower, 25 spellpower is still 1.25%. Due to the very high spellpower coeficients of affliction spells this will probably be a greater increase. (only the immolate DD has a coefficient below 80% for affliction. So a 1.25% increase in spellpower is going to generate a larger total damage gain over the crit meta.
On another note: the crit meta does not affect Pandemic PRocs, as those are based off your crit %, but not considered actual crits. If they were considered crits, it is very likely that the crit meta would surpass the damage ones.

Note: the is VERY rough napkin math. In order to get a better model however you would most likely need to use a spreadsheet or similar to determine exact gains. If some has some better maths on this it would be appreciated.

Wait, are you saying you start casting your sbolt before the tank has actually engaged? First of all in most encounters that's just simply impossible. Usually you have to run in or the boss gets MDed to the tank but does not conveniently wait within your fairly small sbolt range so you can open perfectly.

Additionally casting a sbolt before the tank has actually hit the mob is just wrong and asking for trouble. Even if there's a MD up, if the tank gets a miss and the MD does not crit while your sbolt does crit, you will be screwed. Applying a dot however won't ever be any trouble. I don't see a reason at all to cast sbolt before at least corr, UA and haunt are applied. Starting off your rotation with your least effective dps spell just to proc a 5% dot increase while there are actually 0 dots up sounds fairly flawed to me.

I generally start of with UA as a cast time spell is preferrable in case the tank does get some freak accident miss series. So it usually goes like UA, Corr, Haunt, CoA, Sbolt, SL, Immol and then whatever the timers tell me to do.