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Mangle is imperceptibly different to Shred in terms of PvE DPE?

Post by neiljwd

Roake posted this on the MMO Champ Druid Forum:
After doing some napkin math with mangle and shred I'm wondering what's the point of shred?
mangle tooltip - 500% dmg(35 energy) - 500/35=14.3 dmg/energy
shred tooltip - 500% dmg+20% on bleeding(40 energy) - 500*1.2=600/40=15 dmg/energy

So that's less than 5% additional damage per energy, and that's without factoring in the greater CP regen from mangle, thus making them virtually even. Am I missing something?

Wanted to post it here for a discussion/feed-back.
A zero point seven DPE difference is that it?
IS that really all the difference is? Seems so very close that using Mangle Exclusively wouldn't be a bad thing?
At least in 5 mans/LFR where the tank dances like a hippie on ecstasy? Just hit mangle and don't worry about positional requirement?

Please don't hate on me, I'm asking a genuine question, as I'm NOT AN EXPERT (or close) but the 'maths' seems to make Shred redundant? Hoping someone can sway me back to Shred as Mangle just feels wrong to this kitty....

Post by hymer

Certainly no expert on the numbers, but here's something to tide you over until those people arrive:

You'll want to be behind the boss if you can anyway to avoid parries, cleaves and such. As long as you're there, any little gain is a gain, so even if shred does only 5% extra, that's worth bringing.
Anyway, many have been crying for kitty druids to be less dependent on positioning. Maybe this is the answer to that?

Post by Uiselveti

The DPE difference is actually ever so slightly more than that napkin math, but you are close enough despite leaving out the +weapon damage. Blizzard said that they wanted Shred vs. Mangle to not be a punishing choice & miracle of miracles they actually succeeded.

Now the question is, how long does a fight need to be for the additional 4.8% DPE of Shred to be overwhelmed by the excess energy of using Mangle instead. Keep in mind that for every 5 Mangles (instead of Shred) you get Savage Roar (if glyphed) completely free.

Now I'm not advocating dropping Shred, in fact I use Shred when available, but it looks like I have overlooked an opportunity to drop Shred for a DPS gain. This is definitely an avenue worth investigating, I think.

Thanks, neiljwd, for asking us to take a closer look.

Post by Neffi

Run the numbers in a real-world scenario and see the DPS difference. The gain from Shred is within a healthy margin of error to begin with, so you may find that even though Shred is higher optimal DPS, the extra CP regen of Mangle is easier to manage thus higher real-world DPS for you.

If the math on paper really puts them so close, you have to ask yourself if the challenge of keeping up the rotation of Shred is significantly more than with Mangle. If it is, I'd say Mangle wins out simply for quality-of-life. Like I said, ~5% is within a margin of error to begin with, so if having an easier rotation actually allows you to keep a lower overall margin of error you may find the supposed gains vanish.

Do a set of given bosses using both rotations and keep careful track of your DPS with Recount. If the difference in the end amounts to less than 5%, stick with whatever's more comfortable, remembering that on more difficult bosses, the easier rotation should give you added gains.

Post by Thunderbro

Do a set of given bosses using both rotations and keep careful track of your DPS with Recount. If the difference in the end amounts to less than 5%, stick with whatever's more comfortable, remembering that on more difficult bosses, the easier rotation should give you added gains.

A thing to note: If you're going to run this (or any statistical comparison) you need to have many trials. If you do one run for each rotation and conclude one is better than the other solely based on that data, your results cannot be trusted.

@OT: A thing I never thought about when considering feral rotation is that with Mangle being slightly cheaper, combo points would generate faster throughout the fight. So, even if the difference between Shred and Mangle is only about 5%, the overall difference would be slightly lower (although, I doubt enough to close the gap).

Post by Uiselveti

@OT: A thing I never thought about when considering feral rotation is that with Mangle being slightly cheaper, combo points would generate faster throughout the fight. So, even if the difference between Shred and Mangle is only about 5%, the overall difference would be slightly lower (although, I doubt enough to close the gap).

Actually, no. The reason that we are comparing Shred & Mangle by DPE is specifically to avoid the point you are trying to make. The thing I see that might actually cause Mangle to be a theoretical DPS increase would rely on glyphing Savage Roar. That way, for every 5 Mangles used instead of Shred, you would get a free 12sec Savage Roar. While this is not enough to make keeping Savage Roar up free, it does lower the cost of the buff, which is very significant.

@Neffi:
We do not have access to the performance metrics that would make testing this in a live environment feasible. Blizzard does, and they don't share that info. The best way I can think of to actually test the idea would be to modify the priority list in simc & run each over several hundred thousand iterations each varying the encounter durations, latency, player skill & encounter type to try to form some conclusions. Granted the output of the simulations would not be accurate; however, they should be consistent enough to get a glimpse of the relative value of Shred vs. Mangle.

Post by ganimede

The idea that you 'save' energy to spend on other things is a fallacy, in fact you loose nothing by using Shred.

More (totally contrived but the theory is sound) numbers
Say you use only Mangle over the course of a fight to build CPs, and say you use 5000 energy on mangle alone.

Now say you do 50k damage with that mangle total
50k/5000 = 100dpe with mangle

Now your calculated 5% increase in DPE means had you used shred you'd have 105dpe. Take that same 5000 energy and spend it on Shred instead gives
105*5000 = 52.5kdmg,

52.5k > 50k. Shred is better to spend your CB builder resources on.

Plus you've used 17 fewer GCDs to do it in.
5000/35 = 142 (rounded down)
5000/40 = 125;
142-125= 17

Post by neiljwd

But GCD's aren't that important to a Feral, we have many energy pooling breathers.
And your maths haven't included the fact that you mangle more than you shred for the equivalent energy, Mangling more ='s more CP's.
These CP's can then be spent on a Finisher for some extra DPS....

I'm just throwing it out there.

Plus if you never had to worry about the tank twisting the boss awkwardly, so you can land a hit to refresh rip for 2 secs (after target switching etc) that could be DPS gain.
Against that of course is that Shred ENSURES you're not get parried, if that happens on an occasional mangle, that's lost dps.

Edit: just occurred to me, if you are being asked/forced to target switch, mangle gets to 5 CP quicker to drop a finisher on the add.

Post by Thunderbro

Actually, no. The reason that we are comparing Shred & Mangle by DPE is specifically to avoid the point you are trying to make. The thing I see that might actually cause Mangle to be a theoretical DPS increase would rely on glyphing Savage Roar. That way, for every 5 Mangles used instead of Shred, you would get a free 12sec Savage Roar. While this is not enough to make keeping Savage Roar up free, it does lower the cost of the buff, which is very significant.

If you're ever using the glyphed Savage Roar (other than on pulls or if its down and you have no combo points), you're wasting energy. You should ideally be using Savage Roar with 5 CP's to reduce the amount of times you use Savage Roar (and effectively the amount of energy you use).

Just because you save 25 energy using Mangle, it doesn't make the above fact false.

...your maths haven't included the fact that you mangle more than you shred for the equivalent energy, Mangling more ='s more CP's.
These CP's can then be spent on a Finisher for some extra DPS....

This is the point I was trying to bring up. I just wonder what the actual benefit is.

Plus you've used 17 fewer GCDs to do it in.

Or you generated 17 fewer combo points. Which equates to more than 3 5-CP finishers. But do those extra finishers make up for the loss in DPE from using Mangle?

Post by Neffi

We do not have access to the performance metrics that would make testing this in a live environment feasible.

And what metrics would those be? Coefficients are known. DPE, DPS, DPC, and other values can be divined from what is given. The only metric unknown in a real environment (as far as I know) is boss armor, but those can be figured out by comparing known damage against the damage being taken.

Maybe nobody has tried yet, but all the stuff is there to make an addon that can track this in very good detail.

Post by Trishi

Roake posted this on the MMO Champ Druid Forum:
mangle tooltip - 500% dmg(35 energy) - 500/35=14.3 dmg/energy
shred tooltip - 500% dmg+20% on bleeding(40 energy) - 500*1.2=600/40=15 dmg/energy

Since no one else has pointed this out, I will.

You can't do math like this. You start out with percentages, you end up with percentages. You don't suddenly have damage. That means the result isn't dmg/energy, but %dmg/energy.

So for every energy, that's 0,7% extra damage per energy for using Shred.

The current wording makes the guy sound incredibly biased towards mangle, which kind of makes me more reluctant to even consider his logic.

But if those 3,5% is enough to make up for it, I don't know. I use Shred because it forces me to stick behind the enemy at all times. It's possible that the "cheaper" finishers and savage roars make up for the 3,5% loss.

Doesn't EJ have any theorycrafting on this yet?

Post by Uiselveti

You can't do math like this. You start out with percentages, you end up with percentages. You don't suddenly have damage. That means the result isn't dmg/energy, but %dmg/energy.

I mentioned earlier that the napkin math above was incorrect; however I did not include the corrected math (I actually thought it was self evident). However, as I stated earlier, despite the calculation being incorrect, the conclusion was not.

This is what it should look like using a weapon with 1 DPS (for comparisons of the difference in DPE between the 2 skills the weapon DPS does not matter, as long as it is identical between the 2):

(1 * 5 + 78) / 35 = 2.37DPE

Shred
((1 * 5 +78) * 1.2) / 40 = 2.49DPE

∴
(2.37 / 2.49 - 1) * -1 = 0.04819

There is a 4.819% difference in DPE between using Shred vs. Mangle in a vacuum (ignoring RNG & all damage modifiers).

Edit: corrected a mistyped number & corrected quote owner

Post by ganimede

Mangling more ='s more CP's.
These CP's can then be spent on a Finisher for some extra DPS....
This is true so I took a more indepth look at the numbers. This is what I came up with.

Estimating an answer to this is very specific to the fight but you can make a pretty good guess using some more numbers which I'm going to pull from the Simcraft results page which is the best resource I have access to atm.
Simcraft uses Shred, so we have the following assumptions:
Fight length = 553 sec
Rip uptime 91% = 503 sec
Rip dps = 27k
FB dpex = 162k
#shred = 124
Shred dpex = 80k
total shred dmg = 9.9mil
est. #mangles = (124*40)/35 = 141 mangles
est. Mangle dpex = 80k / 1.20 = 66.7k
est. total mangle dmg = 141*66.7k = 9.4mil
extra cps = (141-124) * 1.40 (40% crit) = 23 extra CPs.

I'll move forward with an idealistic skew on things. Just keep that in mind.

Benefit of Shred
Clearly we have an estimated 9.9mil > 9.4mil just on the use of shred vs mangle. Now we have to see if we can't cover the .5mil dmg gap using the 23 extra cps. The finishers that we'll use these CPs on cost energy and has to come from somewhere. I'll address that later.

Lets look at the best case scenario for these CPs. (for the sake of simplicity I'm ignoring 5cp SRs because it's got near 100% uptime already)
We'll use these to 1) to increase Rip uptime to near 100% and 2) use as many FB as we can. Since sub 25% is already 100% uptime on Rip, we have to gain the 50sec of Rip uptime via Rip itself. Ideally Rip is up for 16+6 =22 sec.

Rip
Best case: using 10 of the 23 extra CPs we get 2 extra 5cp Rips to cover 44 of the 50 missing sec.
So an additional 44sec of uptime * 27k dps ~= 1.18mil extra dmg from Rip via 10 extra CPs

FB
Next say we use another 10 CPs on 2x 5cp FB finishers. Leaving 3 CPs left over.
2 * 162k = 324k extra dmg from FB

So we have an estimated total gain of 1.18mil+.324mil = 1.5 mil extra dmg via extra CPs

Note that the extra energy needed to use the extra Rips and FBs will total to be 110-160 additional energy, which can be accounted (almost) for by not generating the 3 left over CPs.

Conclusion
In this perfect world example, using Mangle can lead to dmg gains over the course of a fight, namely ~1mil dmg over the course of the fight which winds up being 1mil/553sec ~= 1.8k dps. if I've done my math right

But there are more things to consider than what I've outlined here and from my experiance, no fight goes this perfectly. However I can make a few concise statements that I think will be helpful in general.

1) If your parses/logs indicate that you don't have near 100% uptime on Rip, it may be beneficial for you to use Mangle to build CPs to increase the uptime of Rip.

2) If you are at near 100% Rip uptime, start to use more Shreds.

You will move from situation 1 to 2 as your haste and crit increases from gear. Sim your toon yourself for the most accurate info. And as fight length increases Rip plays a bigger role, so Mangle will perform better to help maintain Rip for longer. While Shred will perform better in shorter fights.

Post by neiljwd

Crazy.
Great maths there ganimede, I appreciate your contribution.
And I'm definitely not biased towards this outcome, I genuinely feel a little deflated that Shred isn't our best move, jsut feels so Kitty'ish to me.
As Mangle just reminds me of my dark days as a Mangle bot :(

Still it's good information to have, thank you for that detailed break down ganimede.

Post by ganimede

I'm more than a little surprised myself. I have a feeling that using Mangle probably does not lead as directly to Rip uptime as I make it out to be. I think it is much more likely that the additional combo points generated will come at moments in the fight that are not as ideal as they look in my example.

So I'm going to try simming with Mangle rather than Shred and really see what happens to Rip uptime. Mostly just to see if Simcraft agrees with me that it'll go up even just a little. (It probably won't because someone would have thought of this already and probably because of the timing thing I just mentioned.)

Post by ganimede

So I ran a quick comparison using Simcraft.
The given T14-Heroic profile for Simcraft shows 115333dps
Rip uptime = 91.7%
FB count = 21.5 @ 162k avg dmg

I then loaded the same T14-Heroic profile from Simcraft and changed every use of Shred to Mangle, with the exception of the Shreds used to consume OoC procs which I kept in for obvious reasons, (amounts to 1-2 shreds per fight).
Modified T14-Heroic profile shows 117555dps (2.2k increase)
Rip uptime 92.9% (1.2 increase = 10 sec)
FB count = 22.7 @ 185k avg dmg (1-2 extra FB, but average went up 23k dmg each)
Predicted:
1.8k dps increase
Rip uptime 547/553 = 98.9%
FB count +2

So, close. While the DPS difference is near my estimate, it's greater 2.2k dps increase rather than an estimated max 1.8k dps increase from a supposedly ideal situation. One thing I did not account for is that I assumed FB to only be used at 5cps, but FB is used at < 5cps, Specifically to refresh Rip sub 25% and maybe other uses, I'm not quite that confident with Simcraft to know for sure. Regardless, as you can expect, having more CPs available in those situations makes it hit harder.

Mangle is imperceptibly different to Shred in terms of PvE DPE?

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