## BigRedKitty: Armor penetration stinks

*Daniel Howell contributes BigRedKitty, a column with strategies, tips and tricks for and about the Hunter class, sprinkled with a healthy dose of completely improper, sometimes libelous, personal commentary.*

"Dude, I've got two almost identical pieces of chest-armor, one has more Crit and one has more Armor Penetration. Which of these should I equip: the Gilded Ringmail Hauberk or the Razorstrike Breastplate?"

*"Dude, you need the Armor Pen! Grab the Hauberk, the Armor Pen-chest!"*

"Seriously, you think Arm Pen is good?'

*"Dude! It's so sweet! It reduces the enemy's armor so it totally ramps-up your DPS!"*

"Sweet! I'm totally down with the Hauberk."

/vendor Breastplate

This is what it sounds like, when Hunters cry.

An enemy's armor protects him from physical damage. If we can reduce that armor, our physical attacks will inflict more damage. Any problems with that? Sounds pretty simple, yes?

Blizz permits us two mathematical ways to reduce an enemy's armor: we can reduce a flat amount or a percentage.

Warriors use Sunder Armor to reduce a flat amount of armor. If a warrior is able to stack five Sunder Armors, he will reduce the enemy's armor by 3925; a flat amount. If the enemy has 4000 armor before the attack, he'll only have 75 armor to reduce incoming physical damage. Nice.

Hunter use Armor Penetration to reduce a percentage of armor. At level 80, a hunter requires an Armor Penetration rating of 15.38 to reduce an enemy's armor by 1%. If a hunter has an Armor Penetration rating of 154, and he attacks a different enemy that also has 4000 armor, the hunter will reduce the armor by 10% -- 400 -- and leave the enemy 3600 armor to reduce incoming physical damage.

Warrior have it easy; nerf warriors, right? Don't worry, we're going to dislike them even more later.

But let's pretend our enemy has a lot more armor, like 13,000. Now a warrior still reduces that by 3925, leaving 9075. Our hunter faces a different mob whose health armor is also 13,000, so the hunter reduces it by 10% -- 1300 -- leaving 11700.

Notice that previously we said the warrior and hunter were attacking two separate enemies. Well that's not how we raid, is it? The warrior and the hunter are usually attacking the same mob. And this is where a hunter's armor penetration takes it in the keister.

Armor Penetration is calculated using the mob's acting-armor, not his base-armor. Sunder Armor is calculated upon the mob's base-armor, not his acting-armor. What this basically means is that Sunder Armor is calculated first.

Observe.

We grab our mob with 13,000 armor. We know that the warrior's Sunder Armor reduces it by 3925, leaving 9075.

When the hunter attacked his own 13,000-armor mob, the 10% armor penetration reduced the armor by 1300. But when the hunter attacks the mob that the warrior is attacking, the armor penetration is calculated on the post-Sunder Armor value of 9075. Our Armor Penetration is going to reduce that value by 10% -- 907 -- leaving the mob with 8168 armor.

Well that's not bad, but it's certainly not what we wanted. We wanted 3925 from the warrior and 1300 from the hunter. But since Armor Penetration is calculated on the mob's acting-armor, we only reduced the armor by 907, not 1300. Our Armor Penetration rating, which we worked so hard to raise, has had its value reduced from 10% to just 6.98%, (907 / 13000 = 0.06979 or 6.98%).

6.98% instead of 10%? That's more than a 30% decrease in value from our armor penetration gear! And that, frankly, stinks. Even worse, there is another component to this debacle, and that has to do with the squishiness of the enemy. Observe, again.

For a mob with 13,000 armor, our 10% Armor Penetration was reduced to 6.98%. But what if we're fighting a mob with just 6000 armor?

The warrior still reduces that by 3925, leaving 2075. Now the hunter's Armor Penetration is applied, where 10% of 2075 is 207, reducing the enemy's armor to 1868. But reducing 6000 armor by only 207 is a reduction of only 3.45%!! (207 / 6000 = 0.0345 or 3.45%) Geebuz, that's a positively massive decrease from the 10% armor reduction we see on our tooltip.

The bigger the warrior's Sunder Armor, the less effective our Armor Penetration is. The squishier the enemy -- i.e. the less armor he has -- the less armor-reduction-efficiency our Armor Penetration returns. Basically, the more Armor Penetration rating we hunters stack, the less value we get for our efforts. Stinkin' warriors...

So now we return to our choice of armor: the Armor Pen chest or the Crit chest.

Crit is Crit, right? There's nothing anybody in our raid can do can decrease how effective our Crit is. When a hunter crits, he does more damage and generates Focus for his pet, thanks to Go For The Throat. Crit rocks and that's all there is to it. Crit-damage, pet-damage, it's all yummy. Unlike if we chose Armor Pen:

- Armor Pen can, and will, have its effectiveness immediately nerfed due to the warrior in the party throwing Sunder Armor
- The squishier the mob, the less effective our Armor Penetration will be
- Because we chose the Armor Pen-chest, we reduced our Crit by the amount we would've had, had we chosen the Crit-chest

Armor Penetration is not a bad stat, it's just the least-effective one we hunters have when we factor our party members interfering with our Armor Pen's efficiency. Adding Armor Penetration rating isn't a terrible thing, just remember to never sacrifice Agility or Ranged Attack Power or Crit to take Armor Pen.

And now you know why you should always look at your warriors with a crooked glance; they're in ur party, stealin' ur stats...

/shifty eyes

*Nobody covers raid Hunters like BRK. Looking for more Hunter goodness? Check out our non-raid Hunter column, Scattered Shots or the WoW Insider Directory of Hunter Guides.*

Filed under: Hunter, Analysis / Opinion, (Hunter) Big Red Kitty

## Reader Comments (Page 5 of 5)

## sharkeater75 Dec 29th 2008 1:52AM

no mr bm hunter, nelfer, sometimes we can't choose, instead kittys suck up heals meant for other players, see aoe heals.

yes if pet is dead BM hunters dps sucks.

yes with aoe fights oh bm hunters suck.

and yes, I do all I can to block you from raids.

have a nice day.

killed maylgos tonight too ty =)

## sharkeater75 Dec 29th 2008 1:56AM

again, to suggest that prot warriors are bad for a group, and that bm about to be nerfed hunters are good, is insane.

I'll take sunder armor for my raid, over a crying kitty in the way bm hunter anyday.

spec survival and quit failing.

thanks. your healers.

## Charneldeath Dec 29th 2008 5:55AM

Yay, sharkie found 10 people who can do Aces High! Which has nothing to do with "Cat".

The more you speak, the more you show how much you sir, are the failure. I very much doubt any of your words, or supposed raid accomplishments. Why? Simple. Nobody in their right mind would be in the same raid, nor even the same guild, with an asshat like you.

FYI: I don't even have a level 1 hunter. My main is a tankadin.

## sharkeater75 Dec 29th 2008 11:10AM

yeah tankadin. another win raid spec.

good job.

## Thernderhoof Dec 29th 2008 12:29PM

After 80 comments I doubt anyone is really still reading these, but I really want to say I disagree that armor penetration is crap. I liked what it was at 70 and at 80 its different but still seems cool and i think it definitely can be better than crit.

15.38 armor pen rating = 1% armor ignore

45.91 crit rating = 1% crit

so in same amounts of rating, any X% crit = about 3X% armor ignore

the sunder debuffed boss has 9075 armor, with 10% armor ignore it has 8167.5 armor

9075 armor = 37.33% physical damage reduction, so your physical damage is cut to 62.67%

8167.5 armor = 34.90%, physical damage is cut to 65.1%

62.67% to 65.1 is a 3.88% ((65.1-62.67)/62.67 x 100%) increase in physical damage, for the same amount of rating as 3.33% crit, and IF 1% crit = 1% more damage in the long run, then the armor pen is 16.5% ((3.88-3.33)/3.33 x 100%) MORE effective in this case, which is very possible as its 160ish rating for both, and in pvp this armor amount is a bit higher than a hunter. BUT *disclaimer* armor penetration effects only physical damage, and crit could also proc other things to increase dps.

However since it's a bit sweeter to remove the last part of an enemies armor than the first part, if you continue to pile on armor pen to ignore 50% armor (4537.5 armor, 22.95% physical damage reduc), which is maybe doable with trinket procs and gems, you get 22.95% ((77.05-62.67)/62.67 x 100%) more physical damage, which is 37.76% more effective than the corresponding 16.66% crit, again if 1% crit was equal to 1% more physical damage.

Another point is that stats work together. For example if you had 20% crit, then lets say your damage would be 120% (100% = your damage without crits + 20% if crits are 1% straight more damage). If you add 3.33% crit, then your damage is 123.33%, which is actually a 2.78% ((123.33-120)/120 x 100%) increase over where you were at, whereas if all your damage was physical, 10% armor penetration, as shown above, would multiply with, instead of just add to, your 120% damage for a 3.88% damage increase, 39.57% ((3.88-2.78)/2.78) x 100%, OMG) more effective than the crit assuming everything i assumed to crit before to make these calculations simpler, and at this point and if you pile on armor pen even further, armor pen should definitely outweigh the fact that it probably doesn't affect as many things or increase uptime of talents and abilities like crit.

So basically armor penetration seems pretty good now, which i even just convinced myself after typing all this, and should scale better than other stats in high amounts and when the enemy has high armor (or admittedly less effective against low armor targets). Even though its new, I think its not trash, and therefore should not gtfo off physical damage gear like haste should.

## DavidC Dec 29th 2008 1:33PM

Dead on Calculations. They should FIRE BRK and higher you :-)

## DavidC Dec 29th 2008 1:30PM

One big long winded post and nothing "on point" about armor penetration vs crit? as the little old lady says: WHERE THE BEEF?

So ArPen gets reduced differently and it means it's less effective at times ... So what? It may still be a *better* stat then crit.

And speaking of "less / more" effective, crit is "less / more" effective based upon the RNG!

Let's see some numbers that show 1 crit = X arPen under different circumstances. Show us the numbers so we can make INFORMED decisions.

## jboy Dec 31st 2008 4:17PM

Thanks for an article for hunters that explains why, when choosing between similar gear with either Armor Penetraion versus Crit Rating (or some other stat) it's a good rule of thumb to take the gear without Armor Pen. I had been leaning that way anyway, without crunching the numbers.

And your humor, as always, is gotten by some and "whoosh" for others. Keep up the good work.

## Nildo Jan 25th 2009 6:21AM

Everyone who reads the main article should immediately have to read Thernderhoof's post. He is deadset right. The fact is on the surface arpen may appear to be crap, and in certain circumstances it is less effective than others, but for raid bosses, even those who have been affected by a sunder, arpen will still most always come out on top of crit, and other stats too depending on spec, moreso after the hunter nerf coming in 3.08. Without going into the mathematical mechanics of how arpen works, consider these points:

1. crit stacks linearly, it wont gain as you stack. Arpen stacks, so more arpen = better dps boost.

2. the best way to increase a fractions value isn't to increase the value of the numerator, it is to decrease the denominator by the same amount. take 4/5 as a fraction, increase the numerator by 25% and you get 5/5, or 1. Decrease the denominator and you get 4/3.75 ~1.067. Arpen functions by reducing the denominator, so comparing straight numbers wont always tell the full story.

3. arpen affects NET dps, crit will only increase base dps, so if you reduce a mobs armour enough to boost dps by 1% with pen you will be doing more damage than if you gain 1% crit chance

4. at 20% armour pen (easy to reach, with the current gear) net DPS is increased by 11.02% on a boss with no sunders, or 8.2% on a sundered boss. By comparison, crit chance with 308 rating (equal to the arpen, assuming they have the same weighting in terms of item budget...they certainly do with gems) is 6.71% crit chance. As noted above, that is NOT a 6.71% DPS increase, even with the effect boosted by mortal shots, gfft etc net DPS wont break 7%.

5. with the upcoming nerf to steady shot, AP and to a lesser extent (but still a significant one) agility are going to be less effective. For BM hunters haste is already not very useful, only boosting auto-shot speeds. Which leaves hit (easily capped), crit and armour pen. Most gear comes with good ap/agi already, so many hunters will look to stack mainly crit or arpen.

Summing up, arpen is terrific, in the right circumstances. People need to look at it's application, not the raw numbers. The article is very misleading because it does not delve deep enough or show enough critical thinking about particular mobs and how arpen may boost damage. If you aren't a raider, then ok, arpen may not be for you. If you run lots of 5 mans with a prot pally/druid, get into it, you wont be dissappointed. If you are a raider, have 2 sets of gear, one with 6% hit that stacks crit and a boss set with 8% hit and arpen. Simple.

## Drogoth Jan 3rd 2009 7:29AM

This might be just a bit fantastic, the hec it probably is but most of us are familiar to the term "crushing blow" aight? like warriors on mages for example. Could you create a similar effect with this armor pen rating?

(quote: no questions are stupid there are only stupid answers)

grts

## AQ Jan 5th 2009 10:04AM

Good post, but wrong arguments. Armor Penetration even after sunder armors is an amazing stat.

Wanna see why, ill show you:

boss: 10.000 armor

tank: puts 5 sunders - 10.000 - 3925 =6075 boss armor

Hunter: has 10% armor penetration 6075 - (6075 * 10% ) = 5467.5

Result:

Hunter does alot more dps without pulling aggro.

Conclusion:

Gief more armor penetration.