Priest Theorycrafting for 3.3 – Haste Rating (Part 4)

v3.3

Time to look at haste. Haste is a trickier creature to calculate as there are two main aspects to it:

1. More haste allows faster casting which means more throughput
2. More haste also increases the chance that a spell will be cast just-in-time to prevent death. The so called ‘saving cast’.

The saving casts can not be quantified as far as I am aware as it is dependant on factors such as player skill and latency. We can however estimate the additional throughput that haste grants.

Sections

1. Introduction
2. Mana regeneration including Spell Power and Stamina
3. Mana pool
4. Haste rating
5. Critical rating
6. Summary including LootRank and Pawn values

Assumptions:

• Flash Heal is being spammed (1887 base heal, 80.68% co-efficient and 1.5s cast time)
• Discipline has 2774 spell power
• Holy has 3092 spell power
• 32.8 Haste Rating equals 1% Haste
• Caster currently has zero haste. The effect of moving from 0% to 1% haste is slightly greater than moving from 6% to 7% haste. However the effect on weighting is very small.
• 30% over-heal
• Borrowed Time and Serendipity have been ignored as only FH is being spammed.
• Surge of Light procs are ignored.

Firstly we calculate the MP5 value of a Flash Heal. We calculate this so we can figure out how much an additional FH, enabled by haste, is worth.

Flash Heal MP5 value = (base heal + (SP * SP co-efficient)) * SP MP5 value * (1 - overheal %)

Flash Heal MP5 value is 5775 for discipline and 6134 for Holy.

Secondly we need to calculate the number of additional casts 1 Haste Rating allows.

Cast time for 1% Haste = Base Casting Time/(1 + (% Spell Haste / 100))
Cast time for 1% Haste = 1.5/(1 + (1 / 100))

Cast time for 1% Haste = 1.48149
Extra casts for 1% Haste = 1.5 - Caste time for 1% Haste
Extra casts for 1% Haste = 1 .5- 1.48149
Extra casts for 1% Haste = 0.014851
Extra casts for 1% Haste (%) = Extra casts for 1% Haste/ Base cast time
Extra casts for 1% Haste (%) = 0.014851 / 1.5
Extra casts for 1% Haste (%) = 0.990099%
Extra casts for 1 Haste Rating = Extra casts for 1% Haste / Haste Rating per Haste
Extra casts for 1 Haste Rating = 0.009901 / 32.8
Extra casts for 1 Haste Rating = 0.030186%

So for each 1 Haste Rating you get 0.030186% additional casts. Not much eh? Thirdly we bring the parts together to calculate how much MP5 value 1 Haste Rating brings.

Haste Rating MP5 value from additional healing = FH MP5 value per second * extra casts for 1 Haste Rating
Haste Rating MP5 value (Disc) from additional healing = 5775 / 1.5 * 0.030186%
Haste Rating MP5 value (Disc) from additional healing = 1.1621

Haste Rating MP5 value (Holy) from additional healing = 6199 / 1.5 * 0.030186%

Haste Rating MP5 value (Holy) from additional healing = 1.2344

Now this additional healing throughput comes at a cost. Casting more Flash Heals heals for more but also consumes more mana. So we need to deduct the additonal mana consumption.

Mana consumption per haste rating (MP5) = Flash Heal mana cost * extra casts for 1 Haste Rating / Flash Heal cast time * 5
Mana consumption per haste rating (MP5) (Disc) = 528 * 0.030186% / 1.5 * 5
Mana consumption per haste rating (MP5) (Disc) = 0.5312

Mana consumption per haste rating (MP5) (Holy) = 621 * 0.030186% / 1.5 * 5

Mana consumption per haste rating (MP5) (Holy) = 0.6248

Final value of haste rating is additional healing minus additional mana cost or:

• Haste Rating MP5 value for Discipline = 1.1621 – 0.5312 = 0.6309
• Haste Rating MP5 value for Holy = 1.2344 – 0.6248 = 0.6096

Using this model, at about a spell power to MP5 ratio of about 1:1 the additional throughput generated by haste rating is equal to the the additional mana cost of casting the spells. Thus at ratios less than these I suggest a floor value of 0 for haste rating MP5 value be used instead of a negative value.

Next is critical rating.