Table of Contents
If you use EnhSim's EP calculation, I recommend reading the following guide.
What are EP values?
EP values are those values assigned to each stat(agility, crit rating, hit rating etc.), which tells you how much is that stat worth when compared to other stats. Comparing can be based on almost anything, for example DPS or damage mitigation. EnhSim can calculate EP values based on DPS comparison. Let's take a look at an example set of EP values, often referred as a scale.
attack power: 1 crit rating: 1.5 hit rating: 1.8 intelligence: 0.7
In this example, attack power have been obviously chosen as a base stat. Base stat's value is usually set to 1 and other stats are normalized around the base stat. In EnhSim either attack power or spellpower can be chosen as base stat. Later you will find out how it is done in practise.
This example also tells that 1 crit rating is 1.5 times as valuable as 1 attack power or that 1 intelligence is 0.7 times as valuable as 1 attack power. Let's say 1 point of attack power increases your DPS by 0.35. Then 1 point of crit rating increases your DPS by 0.525 and 1 point of intelligence by 0.245
Where can I use EP values?
You can approxximate item's value with an EP scale. This allows you to quickly compare items and make gear decisions. To make this easy ingame, there are number of addons, which calculate item's value based on EP scale and shows it in the item's tooltip. Pawn and EquivalencePoints are such addons. There are also numerous websites where you can make use of EP scales, for example LootRank and Wowhead.
How EP values are calculated?
In EnhSim, the following method is used to calculate EP values.
- Simulate baseline DPS. Baseline DPS is the DPS value where every comparison is based on. This value is calculated with your current stats.
- Add some amount(called EP range) to a stat. For example increase attack power by 100. Simulate the DPS again.
- Do the previous step to each stat separately.
- Take the difference of each test DPS and the baseline DPS. Divide that DPS by the amount of stat added to get EP value.
- Normalize EP values.
Example to calculate attack power and hit rating EP values:
- Simulate baseline DPS. We got 1000 DPS as baseline.
- Our attack power EP range is 50, so we add 50 attack power and simulate DPS again. Now we got 1030 DPS.
- Crit rating EP range is 20 so we add 20 crit rating and simulate DPS again. We got 1025 DPS.
- Take DPS difference and divide by EP range:
- 1030 - 1000 = 30 DPS. 30 / 50 = 0.6 DPS.
- 1025 - 1000 = 25 DPS. 25 / 20 = 1.25 DPS.
- Normalize EP values. We want to have attack power EP value as 1, so we divide every EP value with attack power's EP value. 1.25 / 0.6 = 2.08.
attack power: 1 crit rating: 2.08
Although, you should know some of the EP values are not calculated by this method. Few stats are calculated using some other EP values:
- Crit rating: melee crit + spell crit(crit test is done in two parts).
- Strength: attack power.
- Agility: attack power + melee crit.
- Intelligence: attack power(Mental Dexterity) + spell crit + spirit(bit of mana regen) + mp5(Unrelenting Storm) + mana.
What can go wrong when calculating EP values?
Here are the main reasons why you might get incorrect EP values.
Going over a cap with EP ranges.
Cap means a breaking point, when increasing a stat, isn't going to give you any benefit. There is a hit cap and expertise cap.
For example, expertise cap at lvl 80 is 214 expertise rating(26 expertise), assuming that boss dodge is 6.5%. Expertise decreases boss's dodge chance by 0.25% per one point. 6.5 / 0.25 = 26 expertise. 1 expertise is 8.1974973675 expertise rating, so you need 214 expertise rating to reach 6.5% dodge reduction. Hit has actually 3 separate caps. Those are special cap(8%), spell hit cap(17%) and dual wield white hit cap(27%).
Going over a cap when calculating EP values is going to result in lower and incorrect EP value. For example, we have our hit near the dual wield white hit cap. Then we increase hit by amount X and go over the dual wield white hit cap by some amount. Then we simulate DPS and divide the DPS difference with EP range to get the EP value right? If we had set our EP range lower, so we wouldn't go over the cap, just reach the cap, we would still get the same DPS from the test. Our EP range would be smaller, resulting in bigger EP value, because of the division operation(DPS difference / EP range). AVOID GOING OVER CAPS WHEN SETTING EP RANGES.
Using too small or too large EP ranges.
Simulating DPS is always random. You will get different results on every simulation run, even if you use the same config file. If you use too small EP ranges, big part of the DPS difference is because of random number generator(RNG). If you use too big EP ranges, your EP values are skewed, because most of the stats do not scale linearly. Exceptions to this rule are attack power and spellpower, they have linear scaling. I cannot tell you what are the correct EP ranges, you have to test yourself. Start low and raise, until you are satisfied with the variation in EP values. YOU SHOULD USE HIGH EP RANGES WITH ATTACK POWER AND SPELLPOWER.
Simulating for too short time.
Simulating longer will minimize the harmful effects of RNG. In other words, you will get better results if you simulate for longer time. When you are calculating EP values with EnhSim, I recommend using AT LEAST value 10000 in simulation_runtime.
Simulating unnecessary stats.
If you are mana capped(out of mana time is 0%) and you are getting near zero EP values for spirit, mana and mp5, disable those three stats by putting the EP range to 0. This saves your time and prevents the RNG doing damage to your intelligence EP value trough those three stats.
Exporting scales from EnhSim.
To make it easier to export EP scales from EnhSim, it supports export strings. Export strings can be defined in enhsim_ep_exports.txt file and it can be done by anyone. Basically, at the end of EP calculation, the lines in enhsim_ep_exports.txt are scanned and EP values are inserted in their correct spots. Then the lines are showed on the screen.
Defining a spot for EP value in export string can be done using $-symbol followed by the name of the stat. For example: $attackpower. You can find the rest of the stat names in the default export strings in enhsim_ep_exports.txt.