I find this discussion is interesting, although it seems like people are pretty defensive about the subject. I think the fact that there can be such varying opinions on something as simple as stats is both a testament to the fact that healing is more an art than a science and that healing philosophy and it's ramifications can vary widely from guild to guild.
No, no, no -- all experts agree that the real
problem is that all the other experts are wrong.
I'm definitely in the "regen is king and throughput is of secondary importance" camp. Even when not doing progression content, I only grudgingly accept that it may be
ok to add mostly throughput stats.
I find the discussion here interesting, but I think much of it misses a very fundamental situation with healing that makes it very different from DPS: You always have more HPS than you need
. You have to. If you don't have more HPS than you have damage coming in, the fight is over -- and over right away. Think of it like an evolutionary biologist: raids without excess HPS don't exist because they immediately go extinct.
That really changes everything, and any model which assumes increasing output generally increases healing "effectiveness" is fundamentally flawed. That's a good model for DPS, but it is inappropriate for healing. Adding throughput buys you a little insurance against rare, unlucky spikes in damage, so it isn't worthless. However, the diminishing returns on increases in throughput are rather harsh. That extra throughput only rarely ends up preventing deaths.
Some may argue that if you have superfluous HPS, that you should simply replace healers with DPS until you do not. That makes perfect sense.... except then you tend to run into mana problems before you run short on HPS
. Don't believe me? Try it. (In fact, you will probably run into range and line of sight coverage issues before you run short on HPS).
There are very good mathematical reasons for this. If you look at your raid aggregate HPS as you increase the number of healers in raid, you will see something very much like a Michaelisâ€“Menten plot seen in enzyme kinetics: it goes up linearly at first and then flattens out. Take a look here for reference
. It is a hyperbolic curve that flattens as the effective HPS from the raid matches the incoming DTPS -- a flattening which definitely will happen by the nature of the situation: you can't heal more damage than you take. Importantly, you HAVE to be on that flat part of the curve where adding more throughput yields a terrible return, because if you're not, the raid dies right away. Put another way: more healers mostly means more healer competition to heal incoming damage and ultimately means each healer's effective HPS gets farther and farther from their maximum possible HPS potential.
In contrast, your raid healer longevity gets returns which are generally better than linear as you change the number of healers. Double the number of healers, and you roughly double the aggregate mp5 (and starting mana pool) between them, but you also decrease the rate at which each healer is casting, which decreases the rate at which each healer burns their mana and increases each healer's oofsr time. Consequently, scaling of healer longevity is significantly better than linear as you change the number of healers.
So what generally happens when you decrease the number of healers in raid? Your raid aggregate HPS decreases slightly, but your raid aggregate mp5 takes a more-than-linear hit the whole way. It is completely unshocking to see mana problems before HPS problems as you decrease the number of healers you have in raid.
Granted, I'm leaving out many details (in the interest of time), but those are the big dynamics. It is certainly possible to have so much excess mana and mp5 that the minimum number of healers you can have is then limited by their maximum HPS. In very short fights, that will happen. For long fights, increasing your maximum HPS may be nearly pointless because you are limited by mana before HPS becomes a limiting factor. To me that's where the dogma that "mana is king on progression content" comes from. Those fights are long.
Still, the most important and invariably true point is that healer throughput must already be present in excess in raids, so adding more gets you relatively little return. Discussion about how adding more spell power can increase your maximum HPS by X leaves me with an overwhelming sense of "so what?" You need to make the case that increasing your maximum HPS actually saves lives, which is far from obvious. Increasing your own effective HPS doesn't show that. Usually, all you are really doing is sniping potential HPS from some other healer and not saving anyone who would not have been saved anyway.
In addition, decreasing the number of healers is an unlikely benefit of increasing throughput. If that is your goal, you are better off adding regen stats since longevity is more sensitive to changes in the number of healers than throughput.
It's quite simple really. That amount of time could be the difference between the heal actually hitting the target or it already being dead. Now I'll admit 7.5ms isn't a long period of time, that is true. However thats that much sooner I can start my next cast, the next one after that and the next one after that. 120 dmg healed means nothing when the person ticks to death the instant before your heal lands. Higher probability of a living target or a sneeze worth of extra dmg healed, that is the question.
Yes, I agree, and what I like is that you're pointing out that the probability of a target living is the relevant metric to optimize, not the amount of damage healed. Damage healed is what statisticians call a surrogate marker
, since it doesn't directly measure what you're interested in. It is not even a very good one, IMO, but we're probably stuck with it. The distinction is important because it is easy to mistake such metrics for real ends in themselves.