Thrill of the Spreadsheet: Timing Focus Fire and Bestial Wrath

***UPDATE***
If you happen to find this article linked on a forum, or when googling, it should be noted that this is now quite out-dated.  I wrote this before Warlords of Draenor came out, when we were still testing things on the beta.  Focus Fire now provides 8% AP buff per stack of Frenzy consumed, which completely changes how it's used from what I described below.  

There's been a bit of disagreement in the hunter community about the proper use of Focus Fire in Warlords of Draenor, where it now includes an Attack Power buff of 2% per stack of Frenzy consumed. And since having a blog means I get to express my opinion about things, I thought I'd take a minute to go over the new mechanic, and what it means for our rotation as BM in WoD.

For our example, I'll be looking at the numbers from a level 100 BM hunter with run-of-the-mill 667 ilvl gear.  When testing, I was around 42% mastery, 30% crit, 14% haste, 16% multistrike, 4% Versa, and a little over 5000 AP.

The issue I'm looking at, primarily, is when Focus Fire should be used, relative to Bestial Wrath.  So for most of our work, we'll only look at abilities that are used during BW, and then compare the benefit we get from using the two abilities separately, to using them together.

Bestial Wrath and Focus Fire Stacking Damage

To start off, lets look at the damage our abilities are doing under different circumstances.

	KC	Melee	Claw	Arcane	Glaives	AutoShot
w/ 5 Frenzy*	15484.5	2097.1	4561.1	8066.5	13400	5274.8
w/ BW	18581.4	2516.5	5473.3	8873.2	14740.0	5802.3
w/ Focus Fire	17033.0	2306.8	5017.2	8687.6	14740.0	5681.0
w/ FF&BW	20439.5	2768.2	6020.7	9556.4	16214.0	6249.1

What you're seeing here is the effect of multiplicative buffs.  If an unbuffed Kill Command does X damage, then during Bestial Wrath, it will do X*1.2 damage; during Focus Fire, it will do X*1.1 damage, but during both effects, it won't do X*(1.3) damage, instead, it will do X*(1.2*1.1).  In the end, that only works out to 2% extra, but considering that you'll be stacking other buffs around Bestial Wrath, and you'll be saving focus so you can use all damage dealing shots during BW, that extra 2% will work out to even more total damage.  

The next part I'd look at is how often we can use each ability.  For cast abilities, this doesn't change.  I can always use 2 Kill Commands, 1 Glaive Toss, and 7 Arcane Shots (assuming I've managed my focus correctly, and do not use Cobra Shot or Focus Fire during BW) and my pet  should, on average, cast 3 Basic Attacks: Smack, Bite, or Claw (this is an average because of the BM Perk which lets your pet reset the CD on its Basic Attack).  

Attack Speed and Haste Effects

Two abilities we'll use during Bestial Wrath, however, are affected by Attack Speed: Pet Melees, and Auto-Shots.  

	Pet Melee	Auto-shot
Unbuffed Cast Frequency	1.66	2.65
Casts during BW w/ 5 Frenzy	7.2	3.8
"    "    w/ FF w/ 0 Frenzy	6.0	4.9
"    "    w/ FF w/ 1 Frenzy	6.3	4.9
"    "    w/ FF w/ 2 Frenzy	6.5	4.9
"    "    w/ FF w/ 3 Frenzy	6.7	4.9

Looking at that chart, two differences immediately pop out in my mind when comparing the first two rows: with Focus Fire we have an extra Auto-shot, while with Frenzy we have an extra Pet Melee. We can then look up to our first chart to see what damage that difference will net. 

With 5 stacks of Frenzy and Bestial Wrath, our one extra Melee is worth (on average) 2516.5 damage; that is to say, by using Focus Fire, we lose that full amount.  However, our Melees in general are worth a little bit more due to the FF AP buff: about 251.7 damage more.  Since we'll still have six Melees, we can multiply that 251.7 by 6, which we'll subtract from the 2516.5 we've lost. That gives us, so far, a net loss of 988.3.  On top of that, we'll also get an extra Auto-shot, and all of our auto-shots will have the extra bonus of benefiting from the FF AP buff**.  An entire Auto-shot with FF and BW (which averages 6249.1 damage) plus the difference between 4 other Auto-shots during BW, with and without the FF buff (446.8 damage) gives us a +8036.3 damage.   Combine that with our loss of 988.3 from losing the Attack Speed buff from Frenzy, and we're at a net gain of 7048 damage.  

That might not sound like much, but that is only covering the difference in damage of Auto-shots and pet Melees.  We'll also get an extra 2% out of our Kill Commands, Arcane Shots, Glaive Toss and our pet's Basic Attacks, which would vanish if we used the two abilities separate (that is the bonus from the buffs multiplying).    

But we're not even done yet. There's still another thing you can do to increase you net damage gained. Because the Focus Fire buff lasts for 20 seconds, if we use it 10 seconds before using  BW, our pet will have three 40% chances to build up Frenzy stacks again before we hit BW.  That's only a 6.4% chance of getting up to three stacks before BW, but a 78.4% chance of getting at least one stack, and a decent 35.2% chance that you'll get two stacks before BW***.  

Another benefit of using Focus Fire at this point, is that you'll be wanting to cast some cobra shots before BW to build up focus.  Using Focus Fire at this point allows you to cast those significantly faster, allowing you to spend more time on harder hitting shots, while still pooling the appropriate amount of focus.

Conclusions:

In the end, while it may not be a huge boost to BM DPS, stacking Focus Fire with Bestial Wrath will be a DPS increase.  For the best results, for 30 to 40 seconds before BW, start saving Frenzy stacks, to insure you have 5 stacks before using Focus Fire, and then use it 10 seconds before BW.  

If you have good RNG, you'll be able to use Focus Fire twice every minute.  Once 10 seconds before BW, and once about 10 seconds after it falls off.  If RNG isn't on your side, it's best to wait until 10 seconds before BW to use it, though.  

Notes:

 *Note that Frenzy does not affect the damage of a shot, only the attack speed, so in this case, this line can be seen as our average damage of each ability, unbuffed.

**It may be worth mentioning that a 10% buff to AP works out to be about an 7.7% buff to an ability which uses Weapon Damage as it's base multiplier, in the gear I wore for testing. That is to say:

The Weapon Damage multiplier = WD + (2.8 * (AP) / 3.5)
∴ 

1191+(2.8*1.1*5023/3.5) / 1191+(2.8*5023/3.5) = 1.077

That percent change will be different, however, depending on the ratio of your base WD to AP.

***These numbers are actually a bit higher, thanks to the Draenor perk Enhanced Basic Attacks, which gives each basic attack a chance to proc a second, focus-free basic attack, which gives you an additional 40% chance to proc a stack of Frenzy.