Hit Rating Spellpower Comparison

The effects of hit rating and spellpower will be assessed and evaluated using the WoW 1.12 client (WoW Classic). We will of course be assessing these in a PvE raiding context.

Background

A spellcaster will often want to do as much damage as they can, to the point of farming for the best gear, seeking the best enchants, purchasing increased spellpower potions, and acquiring World Buffs. An item with an increased hit rating and/or spellpower permanently increases the caster's damage per second, but it often comes at a cost or a tradeoff.

While raiding a caster may come across a potential upgrade. To determine whether the item is a real upgrade the player needs to know the relative value of +hit, +crit, and +spellpower. For example, if a raider can choose between a +1 hit item and a +15 spellpower item, which should he or she choose?

Baseline

Set a baseline understanding of the raider's decisions regarding gear.

Hit rating is more rare than spellpower

Although this may be an obvious statement to many, it is important to understand in objective terms the role +hit and spellpower play for a caster, and the relative value and availability of each.

• Hit rating is rare in absolute terms
  • It is available for limited gear slots.
  • It is available in low doses, often in +1 or +2, and never more than +3, +hit.
  • The total number +hit gear is low, often only one or two items available per gear slot.
• Spellpower is readily available at level 60 for all spell-based classes.
  • It is available for every gear slot.
  • It is available in higher doses, often in 10+, and as much as up to 200+ for on use trinkets, per item slot.
  • There are a large variety of items per gear slot with +spellpower; players have a large selection of gear to choose from.

Hit rating on gear is often more expensive than spellpower

It is worth evaulating the real cost to players for the differences explored in the previous section; how much is a player willing to pay for some x amount of hit or spellpower?

• Players will pay for more +hit than +spellpower in GDKP, DKP, and SR terms (in SR more players are likely to reserve +hit unless they already have it).
• Players will often prioritize +hit if they are not already close to hit cap (i.e., even if they don't pay more for it, they will acquire it first).
• For crafting, +hit gear is often at a premium compared to other similar items.

Conclusion

Although the real cost was not determined, we can surmise that players will spend about ten times more for +hit rating than for +spellpower as hit is measured in the 1's and spellpower is frequently measured in the 10's.

Scenario

There are two players: Raider A and Raider B. Raider A has .99 hit rating and 400 spellpower, while Raider B has .84 hit rating. How much spellpower is needed for Raider B to do the same amount of damage as Raider A?

    Hit   Spell
A   .99   400
B   .84   x

Formula = (base spell + spc) * hit rating / seconds

A is (500 + (400 / 3.5 * 3)) * .99 / 3 = 278

B is (500 + (575 / 3.5 * 3)) * .84 / 3 = 278

This answer is slightly misleading, which will be explained in the Simulations section below. In this scenario, Raider B will need 175+ additional spellpower, or a total of 575 spellpower, to match the damage of Raider A. If we take the difference of 175 spellpower and divide by the difference of hit, we get 12 = (575 - 400) / (99 - 84). This means about 12 spellpower will do the same damage of +1 hit.

Note: This equation is not linear.

    Hit   Spell
A   .99   400
B   .84   575

Simulations

Introduction

Simulations are needed to capture the nuance of randomness which can't be captured using simple math, especially given the limited number of casts needed during a raid. For example, many boss fights in Molten Core, Blackwing Lair, and Ahn Qiraj only last one to two minutes, at most. This is enough time for only about thirty casts of Frostbolt or Shadowbolt.

Here we will create a simulator that determines whether a spell hit or is resisted, and if it hit the damage it hit for. It will then plot a line that takes the average damage per hit.

Examples

A Thousand Casts (50 minutes)

After 1,000 simulated casts the result was what was calculated above, or about 280 damage per second. Notice the spikes on the left of the graph; as the plot moves to the right the line (or damage) gradually starts to normalize.

Figure 1

These results suggest that during a 50 minute fight the difference between ".84 hit with 175 increased spellpower" and ".99 hit with only the base spellpower" will be roughly equal to each other.

A Hundred Casts (5 minutes)

Running less simulated casts effectively creates a zoomed look of the data. The following is a simulation that ran only 100 times. The most consistent result was the ".99 hit rating with 400 spellpower", while ".84 hit rating with +575 spellpower" did more damage. It is worth noting that if this simulation is run enough times, in most cases the .99 hit rating will do more damage than either of the .84 hit options (as noted in the graph above).

Figure 2

Thirty Casts (1 minute 30 seconds)

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