Discussion of Resource Management Related Enchantments for Tanks

Personofsecrets

Hi Everyone,

I just want to go over some values that I came up with. These values pertain to resource management that is offered via jewelry enchantments. The goal is to optimize resource management options and be able to give evidence that one set of enchantments may be superior to another from the perspective of resource management while tanking. The enchantments can be viewed below.

Because resource management has some dependency on the fight, the fight that I choose to use for this study is linked directly below. I'm choosing to use this fight because the skill usage in the fight is representative of the tanking that I have been instructed to perform. It is also a long 550 second fight with various types of phases that is part of a high end raid. I therefore think that this fight shows a good general case to use for comparison of different enchantments.

https://www.esologs.com/reports/kNA2DxmwrP897dyj/#fight=47&source=194&type=summary

The first set of enchantments that I would like to go over is the reduce potion coolodwn enchantments. The below data shows the resource management that I expect to receive from 3 of those enchantments.

This chart is to show that by continuous use of potions during my 550 second fight, I expect to gain about 185,000 resources without potion cooldown enchantments and about 397,000 resources with potion cooldown enchantments. Overall, the potion cooldown enchantments result in about 211,000 gained resources.

The next set of 3 enchantments to go over are for mixed regen. The come from use of the Indeko rune.

After 275 ticks of resource regeneration (one per 2 seconds of the fight), it looks like the use of three mixed regen enchantments lead to about 225,000 resources being gained over the 550 second fight. The resource gained number becomes about 291,000 when considering the effects of Major Endurance and Intellect and how they interract with the enchants. I realize that many more things can become part of this equation and would like to leave it simple for now.

The last set of 3 enchantments that I would like to review are for mixed cost reduction that also come from use of the Indeko rune.

This data is a little different from the previous two datas since this data is being based on the actual number of abilities cast during the linked fight rather than using a hypothetical value based on the length of the fight. Hypothetically there could be 550 casts during the fight, but that would make the data not very practicle. By finding out what my abilities cost before and after use of the cost reduction enchantments and by finding out the actual number of abilities used during the 550 second fight, I can estimate that about 285,000 resources could be saved by use of cost reduction enchantments. And yes, I'm saying that saving resources is the equivalent to gaining resources for the purposes of this study.

Now I would like to go over some other considerations.

The first glaring consideration is that potion use is not totally efficient. For example, it is not the case that someone uses a potion as soon as a fight starts and is already able to restore the complete amount of resource given by the stamina and magicka portion of the potion. It is also extremely the case that potions are useful to restore health. That means that there can be alot of resource waste when using a potion to spike health while either stamina or magicka is high enough to not receive the full benefit of the potion. There is also some other kinds of waste when not using the potions on cooldown. When not using potions on cooldown, their Major Endurance and Intellect bonuses will not be applied. So it becomes compelling to use the potion for those benefits, even if it where to waste resources by the resource pool size cap being bumped into. On the other hand, resources would also be wasted if one is saving a potion for a critical moment, but the Major buffs fall off in the meantime.

I will say that the potion reduction enchantment can help ensure that the Major buffs are always rolling. At the same time, I conclude that this way of resource management locks one into using potions often, therefore shoehorning them into a way of playing to receive max resource regeneration benefits during times that a potion has better utility for some other reason. Other reasons being need for that health spike or even switching potion type for an effect such as lingering health or speed.

The next glaring consideration is that the regeneration stat enchantments suffer when a tank is blocking and therefore having the penalty to stamina regeneration. The indeko rune is a nice source of regeneration when mixed with the infused trait and the linked fight is one in which I actually don't block very often so it is likely to often be working. That being said, I think a more general case is that there is more blocking done when tanking. It may be worth looking into using only magicka regeneration enchantments, but stamina management is also important. Just like with the potion cooldown enchantments, this issue also seems to be locking one into playing in a certain way in order to achieve the maximum benefit. And again, Major Intellect and Endurance need to be contantly rolling to get maximum benefit from the enchantments.

The last thing I would like to consider has to do with the cost reduction enchantments. The enchantments are only going to be receiving a maximum benefit when a player is using most of their global cooldowns to cast abilities. I think that the fight I chose works well since there are some points with downtime. One thing that can also be said is that since I am not actively blocking enemies, my number of casts is artifically high. There is probably some truth to this since actively holding enemies, blocking their attacks, and avoiding their mechanics should definitely impact the number of abilities cast. Of course we are all still casting abilities when actively tanking an enemy, but it is reasonable to think that our global cooldown use for abilities isn't as efficient.

With the above data and considerations I do come to the conclusion that the cost reduction enchantments are most likely going to be the best ones for resource management. Please review this reasoning. Firstly, the number of resources generated by cost reduction enchantments is greater than the potion cooldown enchantment example by around 30%. Additionally the playstyle using cost reduction glyphs does not suffer as much from holding a potion back. This is to say that not only can cost reduction enchantments lead to a high gain of raw resources, but compared to potion cooldown enchantments, they also add to player utility by allowing them more free usage of their potion. I also have the opinion that resource generation waste isn't as bad when using cost reduction enchantments as it is when using other options. Technically resources could be seen as being wasted when one isn't casting a skill while using cost reduction enchantments. But such waste is more incremental, less critical, and, in my opinion, less likely than use of a potion that doesn't fully return both stamina and magicka. Also, cost reduction works while blocking, so the user will have steadier stamina compared to if they were relying on regeneration enchantments. There are probably still some cases where regeneration can pull ahead since the regeneration value I found is the largest one. Cases such as scenarios with low global cool down usage or times when one doesn't need to block may show regeneration enchantments to be strong, but I feel like the cost reduction is more likely to give a benefit in the average case and not cause the player to have to play in a very specific way in order to be confident in the resource management.

The ability to hold back a potion and save it for later is of such high utility that it can even be a primary way of succeeding in certain scenarios. You can imagine, for example, going downstairs during Cloudrest. It's nice to be able to be supporting the group while saving the potion for when it's time to go downstairs. One can save their potions when using potion cooldown enchantments, but that would eat into the efficiency of that source of resource management. One last case that seems to be made of cost reduction enchantments seems to be that having a variety of ways of resource management, rather than relying on just one way, allows one to be more flexible with how they play and, though hard to measure, flexibility can be extremely important toward success.

Anyhow, please tell me what you think of the above analysis and tell me where I may be right or may be going off track. I would like to see some other opinions. Thank you.

Kuratius

Your math for the cost reduction enchants implies you used their full value to make your calculation, which is not correct. You should model them as if they were reduced by % cost reduction sources (this is because of the order in which the game calculates cost reductions, first flat, then percentage).

Personofsecrets

Kuratius wrote: »

Your math for the cost reduction enchants implies you used their full value to make your calculation, which is not correct. You should model them as if they were reduced by % cost reduction sources (this is because of the order in which the game calculates cost reductions, first flat, then percentage).

Thank you for the suggestion. Can you elaborate on the following part?

"You should model them as if they were reduced by % cost reduction sources"

What I did was take values from the character sheet, equip the jewelry, then take the values from the character sheet again. I can see that retesting the values with worm equipped would probably be appropriate since that is a common buff affecting the cost reduction stat. Would you suggest any other buffs to keep track of when performing this test?

Kuratius

Look at the equation for it.
(basecost-flat)*percentReduction expands out to basecost*Percentreduction-flat*Percentreduction, so the flat bonuses get reduced by the Percent reduction instead of granting the full value.

There are loads of passives that grant cost reductions. Many weapon tree passives, racials, class passives, armor passives, skills, etc. Most skills will have somewhere on the order of 5 to 10 percent cost reduction even without building for it. The easiest way is obviously to test it and look at the skill tooltip in-game instead of taking the character sheet value of the jewelry. The more sophisticated way is to make a list of all types of cost reduction.

You were wearing light armor during your test, but the cost reduction was almost exactly 640 on combat prayer, that's a dead giveaway that you probably didnt account for it.

It used to be the opposite order, i.e. first % reduction, then flat reduction. I cant give you the exact patch note where it was changed, but it was a few years ago. If they changed it back then that's probably an unintended regression since afaik it wasn't mentioned in any of the patch notes recently.

Personofsecrets

Kuratius wrote: »

Look at the equation for it.
(basecost-flat)*percentReduction expands out to basecost*Percentreduction-flat*Percentreduction, so the flat bonuses get reduced by the Percent reduction instead of granting the full value.

There are loads of passives that grant cost reductions. Many weapon tree passives, racials, class passives, armor passives, skills, etc. Most skills will have somewhere on the order of 5 to 10 percent cost reduction even without building for it. The easiest way is obviously to test it and look at the skill tooltip in-game instead of taking the character sheet value of the jewelry. The more sophisticated way is to make a list of all types of cost reduction.

You were wearing light armor during your test, but the cost reduction was almost exactly 640 on combat prayer, that's a dead giveaway that you probably didnt account for it.

Thank you for elaborating and please pardon me, when I wrote "character sheet," I actually meant that I took values from the from the skill tooltips. And yes, though I have light armor on for this particular fight, that is one thing that is unusual. There are more fights where I am in heavy armor or medium armor so I decided to not wear light armor when finding ability costs. Other fights, where I have more traditional tanking armor types on, were not as long so I wasn't sure if I should be so satisfied with using those for analysis.

It could be that, thanks to the light armor passives, I was able to more comfortably cast more skills in this fight that I chose, thus making cost reduction appear to have better resource management. At the same time, I used all spell damage glyphs, so I'm not too sure that my ability use would have been effected that much if I had instead been using heavy armor and resource management glyphs.

I think that maybe a good way forward is to get more fight data from more varying fights and seeing how the cost reduction enchantment performs in those. That may be the best way to see if there are some biases benefiting cost reduction.

Kuratius

Personofsecrets wrote: »

Kuratius wrote: »

Look at the equation for it.
(basecost-flat)*percentReduction expands out to basecost*Percentreduction-flat*Percentreduction, so the flat bonuses get reduced by the Percent reduction instead of granting the full value.

There are loads of passives that grant cost reductions. Many weapon tree passives, racials, class passives, armor passives, skills, etc. Most skills will have somewhere on the order of 5 to 10 percent cost reduction even without building for it. The easiest way is obviously to test it and look at the skill tooltip in-game instead of taking the character sheet value of the jewelry. The more sophisticated way is to make a list of all types of cost reduction.

You were wearing light armor during your test, but the cost reduction was almost exactly 640 on combat prayer, that's a dead giveaway that you probably didnt account for it.

Thank you for elaborating and please pardon me, when I wrote "character sheet," I actually meant that I took values from the from the skill tooltips. And yes, though I have light armor on for this particular fight, that is one thing that is unusual. There are more fights where I am in heavy armor or medium armor so I decided to not wear light armor when finding ability costs. Other fights, where I have more traditional tanking armor types on, were not as long so I wasn't sure if I should be so satisfied with using those for analysis.

It could be that, thanks to the light armor passives, I was able to more comfortably cast more skills in this fight that I chose, thus making cost reduction appear to have better resource management. At the same time, I used all spell damage glyphs, so I'm not too sure that my ability use would have been effected that much if I had instead been using heavy armor and resource management glyphs.

I think that maybe a good way forward is to get more fight data from more varying fights and seeing how the cost reduction enchantment performs in those. That may be the best way to see if there are some biases benefiting cost reduction.

There are some tricks you can do by taking the average weighted-by-usage cost of your skills, which also allows you to treat flat reductions as a percentage reduction mathematically, assuming your rotation is roughly constant when averaged over a long period of time.

Then you have an (within itself ) additive % reduction that can be multiplied with other reductions. It also makes it much easier to compare it to other reductions directly.

It doesn't give you insight into outliers like mist form where cost reduction is applied per-tick, but it gives you an idea for the particular set of skills you're interested in, and it gives you the tool you need to compare the two.

You can also work with "effective mana regen" and "effective mana pool" once you've done that, since you can divide by the cost reduction multiplier to see by much it increases the value of base mana and base regen.

In some cases there are even local maxima, but afaik only if one of the sources is multiplicative and if ZOS hasn't moved the curve away far enough to avoid them.

EF321

I've heard that stamina reduction enchant also affect dodge roll cost.

Personofsecrets

EF321 wrote: »

I've heard that stamina reduction enchant also affect dodge roll cost.

Thank you for mentioning - I had no idea that was the case.

Zodiarkslayer

I am glad, that someone wants to make an educated discussion about ressource management for Tanks. That being said, I fear I have to spoil the party: @Personofsecrets Do not take it personal, please.

EF321 wrote: »

I've heard that stamina reduction enchant also affect dodge roll cost.

You heard wrong. Bash, Block, Break Free and Roll Dodge are considered "Base Actions", not Abilities. NO version of ability cost reduction is going to reduce the cost of them, not feat cost, not prism cost, not racial passives, nor skill line passives.

Now for the real critisism.
Your modelisation leaves out several important major factors, that WILL shift the result of your analysis.
1) Mundus: Most Tanks take the Attronach Mundus Stone for a reason. Higher Base Magicka regeneration means more effect from percentage based buffs like minor/major Intellect or light armor passives. And the higher your base is, without the enchantment, the more inefficient the increase by the enchantment becomes.
2) Food Buff: Basically the same as above when it comes to recovery food (Suger Skulls, Witchmothers Potent Punch or Citrus Filet).
3) Race: It is a difference if I take a Nord, with no significant sustain boost, a Redguard, who only takes cost reduction to weapon abilities, a Woodelf, who gets flat increase in Stam recovery, a Breton, who has both flat cost reduction for Mag Abilities and Recovery or an Imperial, who has the flat reduction to all ressources! Again, the shift at the base influences the effectiveness of each enchantment option.
4) Potion: Depending on the content, your abilities and your team's composition, you will have to run different potions. Minor Heroism, for example, or Immovability, or Speed. That will also muddle your calculation, because of the presence of either Major intellect or Major Endurance. And the base uptime of Major Fortitude/Endurance/Intellect is untouched, because a named Buff will always replace its previously cast/applied Buffs of the same name. That alone rules out the Potion Redution Enchantment, in my book. The reduced cooldown timer only inceases your consumption of potions, while delivering only ~8k additional ressources over the time of the normal cooldown potions.
5) Abilities: There are Abilities, that can convert one ressource into another. Spell symmetrie for example. If you can run any one of them, your need for a certain ressource is much lower. Additionally, Wardens or Templars can use class abilities to generate ressources.
Also, consider that the need to have Stam and/or Mag is primarily dictated by the amount of abilities that use either of them and the magnitude of the ability cost and its duration. To illustrate that, consider how expensive Dragonknight abilities on the Magside are, versus the Stamina costs of SnB abilities. A Dragonknight Tank will need both, but not the same recovery in both.
Considering that, the assumption to need to spec into all ressource regeneration equally is absurd.
6) Action costs: As noted above Bash, Block, Break Free, Roll Dodge and Sprint take all stamina as costs, but cannot be reduced by your proposed enchantments. However, they constitute 50% to almost 90% of a tanks stamina consumption, on average.
7) Group Buffs and minor Endurance/Intellect: Having additional groupsourced buffs will again muddle your calculation. Especially minor End/Int is an option, not a must, on a Warden Tank or minor Int on a Sorc Tank. Even if you are neither, a groupmember might apply it to you regardless.
8) Healing: Abilities that heal based on MaxHealth are by far the best option for health regeneneration for a Tank. Nobody will trade off a ressource recovery, that he desperatly needs, for a small amount of a ressource per second of which he has tens of thousands of and can regain maybe 20k to 30k of at the touch of a button. That logic alone should dismiss any tristat recovery or reduction options.

To sum it up:
a) You are disregarding too much influence factors in your modelisation, for it to be representative.
b) The coice of options is also too limited on one absolutely unimportant (Potion Cooldown Reduction) and two limitedly useful ones, because one third or two are not effective at allmost all times.
c) The assumption, that all builds would need equal amounts of stam, mag and health at all times, is absurd.

code65536

I just saw this thread...

1. Cost reduction jewelry does not affect roll dodge. Item sets that reduce or increase costs (e.g., Battlefield Acrobat) affect roll dodge, but that's going off-topic.
2. I've been using the Indeko cost reduction glyphs for the past year, and I love them.
   • That said, I change the mix as needed depending on the situation (what class I'm using, what fight I'm in, etc.). My default configuration is 2x tri-cost, 1x block cost. But I might get rid of the block cost if I'm not blocking a lot on a certain fight. I might add a single-stat stamina reduction on fights where stam is important. For example, on Lokkestiiz as the main tank, I run 2x single-stat stam reductions and a single tri-stat reduction, since the vast majority of your resource consumption on that fight is spamming reflect and you are rarely if ever blocking, and on Yolnahkriin as a non-DK tank, I swap one of the tri-cost reductions to a stronger single-stat stam cost reduction, to mitigate the cost of using the rather expensive Fighters Guild "chains" for pulling in the fire atros (obviously, a DK tank with magicka chains would not want to do this).
   • I hate potion cooldown (Vorador kept suggesting it, and I kept ignoring that suggestion) because I'm cheap and don't want to burn through a million potions.
   • Recovery suffers from the problem that regen for your block resource is stopped while blocking.
   • For years, reduction has always been stronger for sustain than recovery, for everyone who casts a lot (esp. for DDs, not that any DD would want to trade a SD glyph for a sustain glyph... but if they were to, they'd be far better off with reduction than recovery). The thing is, recovery is better than reduction during periods when you aren't doing anything, so you, well, recover faster. But I don't think those moments are particularly important. What's important to me are the bursts of activity. Like when chaining in everything at the start of a trash pull. Or the quick succession of actions needed to chain atros under Yolnahkriin. And for these kinds of bursts of activity, reduction is just more useful.
   • For Mistgrove Shitgrove er, I mean, Rockgrove, cost reduction is extremely nice because it affects the cost of Mist Form and is the only form of sustain that works when misting through the flaming dumpster fire excuse for balance, er I mean, totally fair and balanced mechanics.

3. Zodiarkslayer wrote: »

   And the higher your base is, without the enchantment, the more inefficient the increase by the enchantment becomes.

   What? No, that's incorrect. The absolute amount of sustain that's added does not change. Now, you could say that adding 100 to 1000 is a 10% change whereas adding 100 to 2000 is only a 5% change, but, in this context, why on earth are you even looking at relative change instead of absolute change?

Zodiarkslayer

code65536 wrote: »

"... why on earth are you even looking at relative change instead of absolute change?"
[/list]

That is an excellent question. The answer is straight foreward and complex at the same time!
When you have a multitude of influencing factors, one cannot judge on two isolated ones alone. As a change in any of the other factors has an influence on your outcome, your overall best decision has to be made not on absolute gain, but on cost of opportunity.
For example, if I go 3 times Magika recovery it does not mean I have zero Stam recovery. Therefore I have to take both Stam and Mag Recovery before and after my influence into account. And at the same time know the cost of not making it a cost reduction glyph both times. That all is based on your gear, your stats your race, mundus, ...(long list)..., before and after.

This is multidimensional linear algebra, a classical optimisation problem for micro economics.
Or in other word: It depends...

code65536

Zodiarkslayer wrote: »

code65536 wrote: »

"... why on earth are you even looking at relative change instead of absolute change?"
[/list]

That is an excellent question. The answer is straight foreward and complex at the same time!
When you have a multitude of influencing factors, one cannot judge on two isolated ones alone. As a change in any of the other factors has an influence on your outcome, your overall best decision has to be made not on absolute gain, but on cost of opportunity.
For example, if I go 3 times Magika recovery it does not mean I have zero Stam recovery. Therefore I have to take both Stam and Mag Recovery before and after my influence into account. And at the same time know the cost of not making it a cost reduction glyph both times. That all is based on your gear, your stats your race, mundus, ...(long list)..., before and after.

This is multidimensional linear algebra, a classical optimisation problem for micro economics.
Or in other word: It depends...

That is an impressive amount of rambling to convey nothing meaningful.

I emphasized, in my post, the phrase "in this context". So what is the context? We're comparing various options for obtaining sustain from jewelry enchantments. All three types grant sustain through flat, absolute bonuses. Furthermore, in practical usage, we only care about the actual absolute resources gained or saved; abilities cost X amount of magicka, not Y% of your recovery stat.

Zodiarkslayer

code65536 wrote: »

" to convey nothing meaningful...."

... to you.
Alright...trying to keep it simple.

Example(s):
Reduction is way more effective when applied to high cost abilities. Sustain gain is therefore higher. Right?
Recovery is ZERO when your health/stam/mag bar is full. Therefore you have no sustain gain.
Tell me how do you choose?

What if had no abilities, that use health as a ressource? Do I have sustain or not?
Or, if I only use Pierce Armor and Leash on my magSorcTank? And no other Stamina ability?

If I have to block, which occasionally happens while tanking, I have no stamina sustain from any of the proposed glyphs, because while blocking I cannot use a potion, an ability or have my regen tick.
On a Healer (see OPs ESOlog), what do I care about my Stam Pool, except for sprinting and roll dodging? What good is Stamina cost reduction there? Does it give sustain then?

If I need 2k Stamina and 15k Magicka returned in ten seconds, why would I use Prismatic Glyphs when Magicka only cost reduction or recovery is the obviously better option? Or only 20K of Stamina over ten secs?

The truth is this: Potion cooldown and Cost reduction are conditioned to events. Therefore either necessitating a certain, somewhat limiting play style that uses all ressources or being at least partially useless, when not using all ressources.
At the same time recovery is only usefull when it ticks and when it replenishes the ressource you have used, in time.

code65536

Zodiarkslayer wrote: »

code65536 wrote: »

" to convey nothing meaningful...."

... to you.
Alright...trying to keep it simple.

Example(s):
Reduction is way more effective when applied to high cost abilities. Sustain gain is therefore higher. Right?
Recovery is ZERO when your health/stam/mag bar is full. Therefore you have no sustain gain.
Tell me how do you choose?

What if had no abilities, that use health as a ressource? Do I have sustain or not?
Or, if I only use Pierce Armor and Leash on my magSorcTank? And no other Stamina ability?

If I have to block, which occasionally happens while tanking, I have no stamina sustain from any of the proposed glyphs, because while blocking I cannot use a potion, an ability or have my regen tick.
On a Healer (see OPs ESOlog), what do I care about my Stam Pool, except for sprinting and roll dodging? What good is Stamina cost reduction there? Does it give sustain then?

If I need 2k Stamina and 15k Magicka returned in ten seconds, why would I use Prismatic Glyphs when Magicka only cost reduction or recovery is the obviously better option? Or only 20K of Stamina over ten secs?

The truth is this: Potion cooldown and Cost reduction are conditioned to events. Therefore either necessitating a certain, somewhat limiting play style that uses all ressources or being at least partially useless, when not using all ressources.
At the same time recovery is only usefull when it ticks and when it replenishes the ressource you have used, in time.

Sigh. I'm not sure how you have strayed so far from what I originally quoted and replied to.

So, let's keep it simple: one of your criticisms against the OP, to which I replied (and quoted), said, "And the higher your base is, without the enchantment, the more inefficient the increase by the enchantment becomes."

That is simply not true. 100 extra recovery is 100 extra resources per tick, regardless of whether your base is 1000 or 2000.

(Similarly, 100 cost reduction is still 100 extra resources per cast, regardless of whether your skill cost is 1000 or 2000.)

Yes, if you are oversustaining, then the recovery isn't going to do anything for you. But if you're oversustaining, you probably don't care about any of this in the first place.

(Also, the OP is a tank, not a healer. The log he linked is that for Falgravn HM, which is a fight where the OT in some groups plays the role of an off-healer; additionally, I imagine that the OP used tri-stat glyphs for the comparison because it makes for a more direct comparison with potion cooldown using tripots and because tanks often use both resources.)

Zodiarkslayer

Alright, I'll start over. Let's leave the baggage behind us, shall we?

If one wishes to make a decision between three options, one cannot only look at the absolute numbers.
One also has to measure the numbers proportionally in the same dimension. This is only possible, because OP defined:

Personofsecrets wrote: »

"And yes, I'm saying that saving resources is the equivalent to gaining resources for the purposes of this study."

However, there is no explanation why. Especially for the fact that there are three dimensions that have to be considered, Health, Stam and Mag. Why is health ignored? There are health abilities, that tanks use.
To make all three options comparable one also has to make sure, not to ignore the conditions under which all three effects occur. In our case we have to find a time frame in which all effects can occur and can run fully. Following that, the 21 second cooldown of potions is not comparable with ressource gains every two seconds and not comparable with cost reduction, unless we assume one ability cast per second. We have to take 42 seconds, rather than 21s or even 550s, to ensure we have a comparable set of numbers. So in 42 seconds we can:

• reduce costs of abilities by 3(number of glyphs)*213(cost reduc)*42(duration)=26.838
• recover ressources by 3(number of glyphs)*134(increase)*3(health,mag and stam)*21(recovery ticks)=25.326
• and drink two potions for a total of 2*(8369+7583+7583)=47.066

And that obviously changes when we do not account for health:

• reduce costs of abilities by 3(number of glyphs)*213(cost reduc)*42(duration)=26.838
• recover ressources by 3(number of glyphs)*134(increase)*2(mag and stam)*21(recovery ticks)=16.884
• and drink two potions for a total of 2*(7583+7583)=30.332

So much for the Math. Now the discussion:

• a) The condition for using the potion glyph is highly circumstantial. It has to be on cooldown and the ressource pools have to be depleted by at least 8369 and 7583 to be fully effective, which is usually 40% to 50% of the total ressource pool. One has to ask: How probable is that these two conditions occur simultaniously, every time? The situational influence is simply not controllable. Therefore we cannot expect 47k and 30k as sustain, but rather a significantly lower number. In addition the ressource gain is dependent on 3 glyphs being used. And falls off if I only use two or one glyph with 29s or 37s cooldown respectively.
• b) The Recovery has no condition, other than a depletion of the respective pool by 402 every two seconds. That makes it highly reliable, but low yield.
• c) Cost reduction can only occur, if an ability is cast. (In my limited personal experience) It is questionable, wether that estimate of one cast per second is viable. There are always times where there can be no casts (Mechanics and boss heavy attacks I have to block, positioning, etc.), or where there will be serious detriment for recasting too early and not letting an ability fully run, the most obvious example for tanks being overcasting taunts. In addition the reduction does not apply to base actions (bash, block, etc. ), which are an important part of a tank's toolkit.
• d) In the context of one's build's neccessities, it is unlikely that the drain of both (or all) ressources is equal at any time. We have to assume that one or another is used more and under a higher drain. So a prismatic recovery or cost reduction will always be at least partially inefficient (becasue of temporary ineffectiveness) as a result. However it still dominates the option of two different single stacks, reduction or recovery.
• e) My definition of sustain in ressource REgain. I cannot look at gain alone without looking at drain at the same time. And also look at the Max ressource pool, that I drain from.
• f) For the sake of the discussion the presence of minor and major Intellect and Endurance have been emitted, since one cannot control the minors only if being a Templar or Warden themselves. But assuming a trial environment, it becomes highly likely all four buffs have high/total uptime. In that case the scale tipps massively in favour of the recovery options (factor 1,45).

My conclusion is simple:
Dismiss the potion glyph, because of unlikely circumstances and playstyle/build restriction.
Take two prism glyphs and one single stack recovery glyph of choice to maximise the sustain effect for the more drained ressource, over the reduction glyph ones. Excercise casting discipline to minimise drain at the same time.