Strawberry's Windfury 2.1

''This page appears to be severely out of date. Judging by the title, it was created at Patch 2.1. As I write this, it is Patch 3.3. These problems appear to have been addressed.''

This is math and analysis done from Strawberry on the USA WoW forums documenting exaustive research on how Windfury acts/will act and what is best to do about Shaman Buffs. It is archived here as it will continue to be useful until significant changes have been made to the talent and posts disappear on the forum.

Overview

 * Change to Enhancement is needed, as it nerfs the excessive burst DPS that shamans are capable of.
 * Sustained DPS, however, takes a big hit from this change.
 * The change makes SLOW offhand weapons, even those with Significantly Lower DPS preferable to fast ones. This is inconsistent with other classes, and limits shamans' weapon choices.
 * Other weapon enchants are not acceptable replacements, since they do not scale with melee stats.
 * To fix this, simply make offhand windfury procs not suffer the 50% offhand damage reduction.
 * This will still nerf shaman DPS by ~5% compared to current, due to the WF5/WF4 exploit, but this is far more reasonable, and will maintain sustained DPS while still preventing the excessive burst DPS.
 * It's also possible to fix this problem by making rockbiter (or some other weapon buff) scale with melee attack power.

Analysis
After a couple days worth of testing, reading other's results and comparing them to my own, here's what I've been able to determine regarding windfury, and my take on what needs to change to maintain the viability of Dual Wield Enhancement spec.

The nerf wasn't as bad as we thought Based on testing, the windfury proc rate, even with the 3 second "invisible cooldown" will remain at ~20% when dual wielding or using a 2h weapon. The exact reason for this is hard to devise - it's possible it's based on a scaling proc rate (essentially, a PPM system that scales with weapon speed), or that there's a sliding chance per swing based on procs in previous swings. Regardless of the reason, though, the proc rate of windfury remains close to 20%. Over an infinite number of tests, I suspect it would converge on 20%. This is a good start, and means that blizzard did put some thought into the change.

Given that, this change is good in theory. Nobody intelligent would argue that the windfury double-procs weren't overpowered, and that getting an effective 30-40% proc rate through using multiple ranks wasn't unfair. That part is undisputed, and needed a fix.

New Problem Arises
But... there is one problem that remains, or more appropriately, I should say was created by fixing one problem. Enhancement Shaman SUSTAINED DPS was on par with where it should be previous to this patch (perhaps a little high when using the WF5/WF4 trick). The methods used while nerfing the sustained DPS had what I believe is a too significant effect on sustained DPS in the process.

This is caused by one simple thing - offhand windfury procs "blocking" main hand procs. Offhand windfury procs suffer the 50% damage penalty, and thus even with the best possible weapons, offhand procs will be significantly less potent than main hand. This is the source of the sustained damage nerf.

How does it work?
It's quite simple. Since the 3 second cooldown on windfury is in place, it means that after either hand procs a windfury effect, neither can proc for 3 seconds following. After an infinite number of tests, you'd find that the procs are in proportion to the speed of your weapons (slightly skewed based on the remainder when dividing by 3).

If you had, say, a 2.5 speed main hand, and 1.5 speed offhand, you will see about 65% of your windfury procs being offhand procs, and the other 35% being mainhand procs. If you replace your offhand with another 2.5 speed weapon, you would get 50% offhand and 50% mainhand procs, on average.

So just use slow weapons?
Sure, that's the best way to do it with this system. However, this is inconsistant with blizzard's itemization strategy in the past. Formerly, some classes would ALWAYS take slow weapons over fast ones due to the inherent advantages. But, though normalization and other methods, they attempted to make all weapons viable, and weapon 'upgrades' more clear-cut, regardless of speed.

This would not be true for shamans. Upgrading your offhand to a better weapon with a faster speed would in fact LOWER your DPS, due to the offhand penelty. The more of your procs that come from your offhand, the worse off you are. This could lead to situations similar to the "Barman's Shanker" - a blue item from a low-level dungeon that, for quite a long time, was better DPS than much higher item level weapons for rogues, due to the simple fact it was slower.

An Example
Knight's Warhammer 2.5 speed one-hand, 118-220 damage, 65.0 DPS. Random Enchantment, green trash drop. 

Gladiator's Bonecracker 1.8 speed off-hand, 111-206 damage, 88.1 DPS Epic arena award. 

Going from the green to the epic gives you an additional 13.1 DPS from white damage.

However, as a result of its faster speed, "upgrading" to the epic offhand means your offhand has approximately 1.5x the chance to eat up your mainhand procs, thereby cutting windfury damage in half. When divided by two for the offhand penalty, the difference in the damage of the windfury procs of these two weapons is almost negligable.

It's safe to assume that your mainhand weapon is going to be at least as high DPS as your offhand. If you're using, let's say, the main hand arena mace, which offhand should you equip if you want to maximize your DPS? You guessed it - the green.

That's the problem. It limits the shaman's effective upgrade paths based on weapon speed more than weapon DPS.

I should note that If they were to correct this problem, it would still be an advantage to go for a slower offhand due to stormstrike. However, it would still be an upgrade to go from a 65 dps weapon to an 88 dps 1.8 speed one - just not as much of an upgrade as it would be to go to a 88 dps 2.5 speed weapon.

Why not just use a different offhand enchant? Rockbiter/Flametongue/Frostbrand?
Because Windfury is currently the ONLY weapon enchant that scales with melee stats. Enhancement shamans have no reason to gain caster stats (crit, spell damage, etc), and stacking them to the point that it would improve flametongue or frostbrand to any significant degree would nerf overall DPS far more than what would be gained. Even if the stats demonstrate that flametongue is an acceptable replacement now, it will not be the case when we're using 100 DPS weapons and Tier 6 gear - in fact, every time gear improves, flametongue and frostbrand get worse speaking relatively. Even in its terrible state, WF5/WF5 is still the best combo on the test server due to this.

Alright, So how can this be fixed?
Quite simple.

Remove the offhand penalty from offhand windfury procs
This will mean that, quite simply, it doesn't matter which weapon you proc windfury off of. It will allow for shamans to make choices regarding weapon speeds (bigger hits or faster ones - your call), while maintaining the same relative DPS with the same item level weapons. It will greatly open up the pool of weapons that Enhancement Shamans would be interested in using, and would prevent there from being clear "best" choices for weapons.

Wouldn't that be a huge DPS boost?
Not really. Current Enhancement DPS is so huge because of the WF5/WF4 exploit. Even with OH procs being larger, it will not compensate for the extra 10% proc rate gained from the exploit. On average, shamans will lose about 15-20% DPS as things stand. With this change, the DPS loss would be about 5-10%. Still a slight nerf, but a reasonable one, that still controls the excessive burst damage that Enhancement Shamans were previously capable of.

Is this the only solution?
There are quite a few other solutions, but this would be the easiest and most elegant solution. Another way to do it, albeit slightly more complicated balance-wise, is to make Rockbiter (or a new weapon enchantment) scale with melee stats in some way. For instance, making rockbiter increase DPS by X plus some percent of your attack power. Or making it function similar to flametongue, dealing a fixed amount of bonus damage per swing - but scaling by some percent of your attack power, and affected by your melee crit. Or something along those lines.

Basically, we either need windfury to work, or another option that will scale with melee. The easiest way is just to make WF scale. The harder way, although it may be better for flexibility, is to give us another option for our offhand other than Windfury.