Healing Throughput for 39 Restoration Druids
TL;DR version at the end (probably your best bet to use as source material for your guide, as no one's gonna wanna wade through this math).
Druid healing benefits directly from three main stats: spellpower, haste, and crit. Spellpower triggers compound effects with the other two stats. Think of it this way: if you already have a ton of spellpower, then getting a little bit of haste will increase the throughput not only of the base healing of a spell, but also the bonus healing from the spellpower you have. So, which stat has the biggest effect on which spell, and when?
While these numbers could vary slightly depending on specific talents a resto druid chooses, the numbers should stay proportionally correct in relation to each other. I'm looking at about a 1% margin of error or better overall e.g. 6 haste rating actually provides 1.006% haste, compared to the 1% I list below.
For a restoration druid at level 39:
6 haste rating = 1% haste
8.33 crit rating = 1% crit
35 int = +1% crit
Regrowth (Heal): 30.15% bonus healing from spellpower
Regrowth (HoT): 9.23% bonus healing from spellpower
Rejuvenation: 16.92% bonus healing from spellpower
Healing Touch: 82.77% bonus healing from spellpower
Swiftmend: 60.62% bonus healing from spellpower
Right away, notice that both Rejuvenation and the HoT component of Regrowth seem to receive only minor bonuses from spellpower, but the math we do later on will show that multiple ticks help bolster the impact of spellpower. Healing Touch and Swiftmend benefit the most. That said, we need to know comparative benefits. We start with all possible healing spells for 39 resto druids.
Base spell numbers, heal size, mana consumed by point and by base mana percent:
Regrowth (heal): 367, 288 mana (35%)
Regrowth (HoT): 38 every 2 seconds, for 6 seconds, 288 mana (35%)
Rejuvenation: 168 every 3 seconds, for 12 seconds, 214 mana (26%)
Healing touch: 818, 247 mana (30%)
Swiftmend: 613, 82 mana (10%)
To translate this into on-the-field healing numbers, we divide the amount healed by the casting time (2.5 for a talented Healing Touch, and 1.0 for Swiftmend's global cooldown).
Base healing per second (hps), healing per base mana % (hp%m) -- higher is better.
Regrowth (heal): 245 hps, 10.5 hp%m
Regrowth (HoT) 19 hps, 0.5 hp%m
Rejuvenation: 56 hps, 25.8 hp%m
Healing Touch: 327.2 hps, 27.3 hp%m
Swiftmend: 613.0 hps, 61.3 hp%m
Right away we see the power of Swiftmend -- fast, cheap, strong. We also see that Rejuvenation has almost the same mana efficiency as Healing Touch, and that the HoT portion of Regrowth does very little actual healing. Most importantly, notice that Regrowth and Rejuvenation together have almost the same healing throughput (hps) as Healing Touch. Once a Rejuvenation is active on a target, then spamming Regrowth raises your healing to the same level as spamming Healing Touch without Rejuvenation active.
So what effect do stats have? How much haste equals how much crit equals how much spellpower? While the answer gets a bit complicated, let's start with haste and crit.
We know to get 1% haste, we need 6 haste rating. Now, a critical heal gives us 50% more healing, so raising our crit rating by 8.33 raises our healing throughput by an average of 0.5%. Which is to say, adding 1% crit rating will make one out of every 100 casts give us 50% more healing. To match the throughput of 1% haste, we need two out of every 100 casts to give us 50% more healing, which is the same as one out of every 100 casts giving us 100% more healing. Therefore, in terms of healing throughput, 1% haste = 2% crit.
6 haste rating = 16.67 crit rating, for the healing throughput of all druid healing spells at 39. Crit looks horrible right now, but Living Seed has something to say about that later on. For now, on to spellpower.
Starting with Regrowth/heal, spellpower provides 30.15% bonus healing. To increase healing throughput by 1%, we need to increase Regrowth/heal by 1% of 367, or 3.67. So, (0.3015x = 3.67), (x = 12.17), meaning we need just a tad over 12 spellpower to increase Regrowth/heal's healing throughput by 1%.
Now we have 6 haste = 16.67 crit = 12.2 spellpower for Regrowth/heal. And here's where it gets complicated.
Haste and crit both multiply the bonus healing you get from spellpower, so the more spellpower you stack, the more healing that haste and crit can bring. Therefore, it actually takes more spellpower to continue to raise your healing throughput compared to haste and crit. Let's pretend you have 200 spellpower, and want to know how best to increase your healing throughput for your Regrowth/Heal. 200 spellpower * 30.15% for the Regrowth/heal spellpower coefficient = 60.3 total bonus healing. With 200 spellpower, Regrowth/heal now lands for 427.3. At this point, 1% extra healing from the same 6 haste or 16.67 crit now gives us an extra 4.273 healing throughput, so you would need (0.3015x = 4.273), (x = 14.17) ...a little over 14 spellpower to match the healing throughput of 1% from haste or crit.
See what happened there? We started at zero spellpower, and got 6 haste = 16.67 crit = 12.2 spellpower, and at 200 spellpower we got 6 haste = 16.67 crit = 14.2 spellpower. Now, nobody but nutcases like myself want to go through all the math, so let's hurry up and make a chart so we can use the information to get to the good stuff. Let's assume resto druids will have either 100, 200, or 300 spellpower. That range will cover most players who stack way low or way high.
Spell (component): spellpower needed for 1% bonus healing after 100/200/300 spellpower:
Regrowth (Heal): 6 haste = 16.7 crit = 13.2/14.2/15.2 spellpower
Regrowth (HoT): 6 haste = 16.7 crit = 13.4/14.4/15.4 spellpower
Rejuvenation: 6 haste = 16.7 crit = 10.9/11.9/12.9 spellpower
Healing Touch: 6 haste = 16.7 crit = 10.9/11.9/12.9 spellpower
Swiftmend: 6 haste = 16.7 crit = 11.1/12.1/13.1 spellpower
Interesting numbers! Now for the twist in the story: Living Seed and Nature's Bounty.
Living Seed gives you a 30% (of Regrowth) dormant heal on a target after a crit from Swiftmend or Regrowth. To calculate these into the numbers above, take the total Regrowth base heal (367 + 114 = 481), determine how much that adds to the Regrowth/Heal, Regrowth/HoT, and Swiftmend crit numbers, then redetermine the haste/crit/spellpower proportions.
Regrowth (Heal): 367, crit = 550.5, +481 Living Seed = 1031.5, i.e. 281% of the original heal.
Regrowth (HoT): 38, crit = 57, +481 Living Seed = 538 i.e. 944% of the original heal.
Swiftmend: 613, crit = 919.5, +481 Living Seed = 1400.5 i.e. 228% of the original heal.
Now, to calibrate the new crit healing stats into the original proportions, let's divide the old crit ratings by the new crit percents of the original heals.
Regrowth (Heal): 16.67/281% = 5.93
Regrowth (HoT): 16.67/944% = 1.77
Swiftmend: 16.67/228% = 7.31
To see the impact, let's put these numbers back in the main chart:
Spell (component): haste vs. crit/Living Seed crit vs. spellpower after 100/200/300 spellpower:
Regrowth (Heal): 6 haste = 16.7/5.9 crit = 13.2/14.2/15.2 spellpower
Regrowth (HoT): 6 haste = 16.7/1.8 crit = 13.4/14.4/15.4 spellpower
Rejuvenation: 6 haste = 16.7 crit = 10.9/11.9/12.9 spellpower
Healing Touch: 6 haste = 16.7 crit = 10.9/11.9/12.9 spellpower
Swiftmend: 6 haste = 16.7/7.3 crit = 11.1/12.1/13.1 spellpower
Check out what Living Seed does to the average healing throughput of crit rating for Regrowth and Swiftmend! Which means you must choose Nature's Bounty if you want Living Seed, since 20% crit chance for Regrowth is like adding 118 crit rating for the heal portion, or 36 crit rating for the HoT portion.
Now that we have the numbers, we can use them to make some decisions about gear strategies. Time for the payoff section.
--* Summary/TL;DR Version *--
The faster ticks of heal-over-time spells will make much better use of haste than the reduced casting time of direct healing spells, since you must cast direct healing spells back-to-back to see the benefits of faster casting time. With this in mind, 39 resto shamans have two viable talent builds, which prompt two strategies for gearing.
For HoT druids, assume that 6 haste = 12 spellpower. Crit rating comes last in all gear decisions unless it acts as a tiebreaker (e.g. 12 int is better than 6 haste). To make the most of a HoT druid, make sure not to refresh a teammate's HoT until your previous HoT runs out.
For Seed druids (choose the Living Seed and Nature's Bounty talents), assume that 5 crit = 6 haste = 14 spellpower. For close calls, choose crit and spellpower (often via int). To capitalize on a Seed Druid build, pay closer attention to your positioning, as you won't have as much mobility when spamming Regrowth. Never worry about refreshing Regrowth's HoT too soon, as the casting time for the Heal portion runs shorter than Regrowth's HoT ticks.
Woot for math! Now, somebody double-check my work
Bwappo
ps. HoT druids will likely prefer the Glyph of Swiftmend to keep Swiftmend from curtailing healing throughput, though the Glyph of Rejuvenation will boost powerful HoT heals even higher. Seed druids may seek the Glyph of Rejuvenation to bolster their weaker HoTs. I don't know if seed druids will want the Glyph of Regrowth, as any teammate under 25% health is already a spam target. Personally, I think I'd take it, as I'd rather take the chance that a teammate gets saved by a seed if the druid gets CC'd.
