Off with his head!

Update: rounded down some numbers which gave a bit inaccurate outcome, been more precise now. Also added the effect of Faerie fire.

We were having a discussion in the Warrior section on our forum on the best tank weapon enchant and the new enchant Executioner came up in this story aswell;
Permanently enchant a Melee Weapon to occasionally ignore 840 of your enemy's armor. Requires a level 60 or higher item.

I wondered if ignoring 840armor would be such a great deal, so i looked up the ammount of armor on bosses (list on end of this post) and most bosses seem to have either 6200 or 7700 armor.
When ignoring 840 armor that is at least 11% of their armor which seems quite a bit.
This doesn't however say the damage you deal will be 11% higher. If i may believe wowwiki, the formula for damagereduction is as followed:
Levels 60+ DR% = Armor / (Armor+400+85*(Level+4.5*(Level-59)))

For a level 73 (bossmob) with 7700 armor the damagereduction will be: 0,39 (so from 100 damage 61 will come through)
For a level 73 (bossmob) with 7700-840 armor the damagereduction will be: 0,36 (so from 100 damage 64 will come through)
So roughly said (correct me when i'm wrong) thats an occassionaly 3% damage increase, assuming my math is correct here. (2,7% actually when not rounding numers)

Executioner can proc when active and lasts 15seconds... when it procs it doesn't stack but it does refresh itsself. In theory you could keep this up with a fast weapon so you would be able to consider this a near 3% threat improvement on damagedealing attacks. (so doesn't apply to Sunder or Demoshout for example) As Devastate (which does deal damage) is likely to be used instead of Sunder after the 2.3 patch as it applies a sunder aswell, the number of damagedealing moves a tank does will even increase.

Btw on a full sundered boss with 7200 armor this will be 0,30 and 0,26 reduction... so the damage reduction is reduced by about 4% (3,6% not rounded).
When also adding Faerie Fire the effect damagereduction will be reduced by 3,8%.


Conclusion:Assuming my view on this isn't crooked then Executioner gives about 3% damageincrease which is quite a bit. (depending on other debuffs)
While 1 damage = 1 threat, defensive stance of a Warrior increases this aswell. Again this enchant won't give you a 3% threat increase as most skills have an ammount of threat "built in" (450 in a sunder for example) we can't talk about a 4% threatincrease.
But what other options are then?

Battlemaster: Permanently enchant a Melee Weapon to occasionaly heal nearby party members of 180 to 300 health when an enemy is struck.
Battlemaster's heal is minor so for keeping urself up don't bother, it is nice for topping up your party members when they get affected by some Areaeffect or something. Threatwise 1 point of healing = 1/2 point of threat so thats less then regular damage, however you will heal 5 people.
Overhealing doesn't give threat tho.

Mongoose: Permanently enchant a Melee Weapon to occasionally increase Agility by 120 and attack speed slightly.
The agility on a proc will increase your dodge and you armor for a bit which is nice for damage reduction, the increase of attack speed will produce a bit of extra rage and some extra hits = extra threat ofcourse.

Potency: Permanently enchant a Melee Weapon to add 20 Strength.
The cheapest of these and thats the main reason why i added it too be honest, to have an alternative for a bit lower budget.
The 20 Strength will increase the damage done = threat but will also improve your shieldblock rating which results in more damage from your Shield Slam = more threat.

In my opinnion the best enchant in this list is Executioner (time will tell) where the least valuable to me seems Battlemaster, Mongoose could be a nice second which makes Potency the 3rd option... unless you value your gold more then Potency will likely get a better rating in your top 3. :)
There are likely more options out there which could make nice tank enchants, Agility to have a fixed ammount of extra dodge and armor for example but those mentioned above seemed the more valuable enchants.


Boss Armor Value's

Serpentshrine Cavern:

Hydross the Unstable: 7700
The Lurker Below: 7700
Leotheras the Blind: 7700
Fathom-Lord Karathress 6200
Morogrim Tidewalker: 7700
Lady Vashj: 6200

Tempest Keep:

Void Reaver: 8800
High Astromancer Solarian: 6200
Al'ar: 7700
Kael'thas Sunstrider: 6200

Hyjal Summit:

Rage Winterchill: 6200
Anetheron: 6200
Kaz'rogal: 6200
Azgalor: 6200
Archimonde: 6200

Black Temple:

High Warlord Naj'entus: 7700
Supremus: 7700
Shade of Akama: 7700
Teron Gorefiend: 6200
Gurtogg Bloodboil: 7700
Reliquary of Souls:
- Essence of Suffering: 0
- Essence of Desire: 7700
- Essence of Anger: 7700
Mother Shahraz: 6200
Illidari Council:
- Gathios the Shatterer: 6200
Illidan Stormrage: 7700

Notice that all but 2 of the bosses have either 6200 or 7700 armor. A similar pattern occurs in the trash mobs: 5475/5700/5950 or 6800/7100/7400 for level 70/71/72 mobs. In terms of percentage reduction, these values result in either 34.15% or 39.15% armor reduction vs attackers of the same level as the mob.