Shattered

So there’s a new tactic available to fire mages as of 5.0.4 that I’ve learned about recently and played with a bit.  It involves three abilities or passive talents that are from the frost school:

• Shatter: Doubles the critical strike chance of all your spells against frozen targets plus an additional 50%. This effectively ensures a crit with your direct damage spells against frozen targets as long as your base critical strike chance is above 16.67%.  After taking into account the 5% critical strike buffs from Molten Armor and Arcane Intellect, or 10% in total, I very much doubt that a high level character will fall below this crit percentage.
• Frostjaw: This is the recommended tier 3 talent choice for fire mages. It silences and freezes the target in place for 8 seconds (4 versus players). Unfortunately, the freezing effect breaks very easily with damage, and to my understanding a spell crit will always break the freezing effect.
• Deep Freeze: The tooltip indicates that this spell stuns the target for 5 seconds, and is only usable on frozen targets. What the tooltip does not say is for that five second duration, the target will be considered frozen, and unlike Frostjaw (or other frost spells), this effect does not break with damage.  In my experience, it lasts the full five seconds regardless of damage.

Combined, these three abilities provide a way to ensure a couple spell crits.  You cast Frostjaw, freezing your target. Then you immediately cast Deep Freeze, extending that frozen period for five seconds. Then you cast some spells and they are guaranteed to crit.

To me, the obvious choice as to when to try this sequence is when you have a Pyroblast! buff.  That way you can ensure a crit with your most powerful spell and the ensuing fireball as well (and perhaps even the spell beyond that, if you have a haste buff active). In theory you can use it to force crits on two successive fireballs, but that seems to be a lesser benefit, and the Pyroblast! buff is common enough.

The question I had, though, is whether it’s worth it.  Casting Frostjaw and Deep Freeze gives you two global cooldowns where your dps is zero. Yes, you make up for it with crits on two powerful spells, but you should also consider that those spells may crit anyway.

So I tried to find out theoretically, before thinking about it practically.

Let’s start with some terminology. FB is short for Fireball, PB is short for Pyroblast, FJ is short for Frostjaw, and DF is short for Deep Freeze.  Further, a “c” following a spell abbreviation means that the spell is guaranteed to crit, as in FBc.

Now for the spell sequence.  The ideal spell sequence is as follows:

• FJ-DF-PBc-FBc-…-PB

The ellipsis represents spells that are fillers in order to allow the fireball to hit the target and activate Pyroblast! thanks to it being the second crit in a row. You could refresh Living Bomb here, or you could cast another Fireball, or you could cast Ice Barrier.  The key is that you are assumed to take identical actions in the alternative sequence so as not to present a meaningful difference.

The alternative sequence is as follows:

• PB-FB-FB-FB-…

The ideal sequence takes four global cooldowns and one fireball cast time, while the alternative sequence tales one global cooldown and three fireball cast times.  As shown below, these times are very similar.

Next are the assumptions I am using to evaluate the sequences’ values. These are rounded but reasonable, and while they won’t get me a precise answer I am confident they will show what sort of general advantage you might get from the strategy.  Here are the assumptions:

• The effective crit rate is 50% for Fireball and Pyroblast.
• The global cooldown is 1.3 seconds.
• Frostjaw has a cast time of 1.3 seconds.
• Fireball has a cast time of 2 seconds.
• Including ignite, Fireballs hit for 25k and crit for 50k. An average Fireball thus does 37.5k damage.
• Including ignite, Pyroblasts cast with a Pyroblast! buff hits for 50k and crits for 100k.  An average Pyroblast thus does 75k damage.
• Inferno Blast is on cooldown or otherwise cannot be used to trigger a Pyroblast! buff.

Let’s evaluate the sequences now.  Sequence 1 takes a total of 7.2 seconds, and does a total of 100k + 50k + 75k damage, for a total of 225k damage. Sequence 2 takes a total of 7.3 seconds, and does a total of 75k + 37.5k + 37.5k +37.5k damage, ot 187.5k damage.

Sequence 1 appears to be the clear winner, but we haven’t quite accurately reflected the damage expected from the sequences. The spells in sequence 2 can crit, and can also crit successively, and if they do you will cast a pyroblast on a Pyroblast! buff instead of mechanically tossing fireballs.  (Note that we are not anticipating Inferno Blast being available, under the assumption that it was used to trigger the initial Pyroblast! buff.)

Sequence 2 presents us with a number of different possibilities of crits and Pyroblast buffs.  In addition, for either sequence there is the possibility that the sequence will end with an active Heating Up buff.  This has value. With a crit rate of 50%, I will assume that if a sequence ends with Heating Up, half the time it will result in another instant-cast Pyroblast, adding 1.3 seconds to the sequence time and 75k to its damage.

Thus, there are two possibilities for sequence 1:

• The ending Pyroblast does not crit, or it does crit but Heating Up is not converted to Pyroblast!: 225k damage over 7.2 seconds (75% of the time).
• The ending Pyroblast does crit, and Heating Up! is converted to Pyroblast!: 300k damage over 8.5 seconds (25% of the time).

The weighted average dps of sequence 1 is (225k/7.2*.75 + 300k/8.5*.25) or 32261.

Sequence 2 is more complicated.  There are 16 separate patterns of crits and non-crits, considering only Fireballs. When you add in the possibility of one, two, three or even four Pyroblasts it requires a spreadsheet to value, with, if I’ve counted correctly, 41 possible permutations of Fireball and Pyroblast crits and Heating Up and Pyroblast! buffs.  A couple patterns are here as examples:

• All four Fireballs crit, resulting in two Pyroblast! buffs. Both Pyroblasts crit, resulting in another Pyroblast! buff. That Pyroblast! crits, resulting in a Heating Up buff, which is coverted to a Pyroblast! buff later. This has a net dps of 50k, but is highly unlikely.
• The first two Fireballs crit, the third one does not, the fourth one does, and the Pyroblast from the Pyroblast! buff crits, resulting in another Pyroblast, which does not crit.  The net dps from this pattern is 31.98k.

The dps values from this calculation range from 17.12k (when nothing crits) to 50k (when everything crits), in sequences ranging from 7.3 seconds to 12.5 seconds. The weighted average dps is 28999.

Thus, it would seem that Sequence 1 has about a 3.3k dps advantage, or an increase of about 11%. Deep Freeze has a cooldown of 30 seconds, but you won’t have a Pyroblast! buff every time it’s up.  Because Sequence 1 takes either 7.2 or 8.5 seconds (depending on whether the final Heating Up buff is converted to a Pyroblast!), let’s say that the sequence represents 20% of your dps time.  The net overall dps gain from this strategy, therefore, would be around 600-700 dps or so.

(One other thing to consider is whether this strategy provides addition benefits by lining up a good combustion. My experience is that it doesn’t work well; ignites from previous spells drop off as you are casting Frostjaw and Deep Freeze, and though two crits from Pyroblast and Fireball have large ignites, they don’t result in significantly larger ignites than you could get without Frostjaw and Deep Freeze.  As always, your mileage may vary with this.)

So that’s theoretical.  What about practical?

There are some practical problems with Sequence 1 as stated above. Sequence 1 assumes instant server reactions and no latency of any kind. What is most troubling to Sequence 1 practically is server lag involving the application of the Frostjaw debuff. In my experience, the server can take approximately 0.25 seconds to register the Frostjaw debuff after it has been cast.  Thus, what happens is that you have queued up a Deep Freeze cast immediately when your Frostjaw cast time is up, but it cannot take effect because the freezing effect has not been applied to the target. In practice what you will have to do is spam your Deep Freeze button (or your /castsequence macro) to try to get Deep Freeze to activate as soon as the Frostjaw debuff is applied.  This reduces the expected dps of Sequence 1 because the time for the debuff to be applied must be added to the Sequence time as zero-dps time.

This presents a further problem. If you have Living Bomb on the target (as you should, and presumably either of the other Tier 5 talents as well, though Frost Bomb presents less of a problem), then it might tick or explode between the time the Frostjaw buff is applied and when you can cast Deep Freeze.  This will remove the freeze from the target and prevent you from casting Deep Freeze at all.  Your Pyroblast and subsequent spells would then not be guaranteed to crit.

Missing Deep Freeze in this manner results in a significant dps loss.  If you lose two seconds of dps time from the miss (in my experience, you would likely lose more), your dps from the subsequent equivalent of Sequence 2 drops to about 23.5k.

In my limited testing on this, I found myself frequently missing in this manner.  I don’t think I missed enough to make Sequence 2 more of a dps advantage, but I do think that the dps gain of the procedure is much less than 600 dps after these practical problems are considered.

—-

At this point I’m going to break from the theory for a second and offer my advice after working through all this.

This strategy will only work against mobs that are freezable. Thus, you’re not going to be using this on any raid bosses that I know of, and using it in group situations might be difficult anyway as the frozen effect is more likely to break.  The time that you will use this is if you’re soloing, particularly with high health mobs, or perhaps in old raid content or the like.

I enjoy figuring out what’s the optimal dps in such circumstances because I think they constitute a large portion of our game play and I think they are neglected by traditional theorycraft in favor of minute analysis of boss fights.  As some people say, it’s trash. Who cares about your dps on trash?

And that may be true.

I invite you to consider things from another angle.

Consider the following scenario from Cata: you launch a fireball toward a mob with the knowledge that the fireball will kill it.  You switch to another target and begin casting pyroblast.  The fireball crits on the first mob and activates Hot Streak.  You introduce yourself to the next mob with two pyroblasts, one right on top of the other.

If you did not enjoy that when such a thing occurred, I advise you to stop playing a fire mage.  Go play a paladin or some boring class.  Simultaneous pyroblasts are FUN.

So it is with this sequence of moves. It could be that, all things considered and as a matter of practice, freezing a mob with Frostjaw, stunning it with Deep Freeze, and getting a pyroblast crit and a fireball crit while it stands there helplessly may not be any better than just lobbing the pyroblast in the first place.

But I think it’s more fun.

So yes, there is a theoretical advantage to the technique, and there is probably a slight practical advantage to it as well. Don’t do it for that, though.

Do it because it’s fun.