Apr 222011

I feel like RSVs (Relative Stat values) are the theoretician’s equivalent to Archeology. No matter how much time you spend doing it, the return you get for your time spent is far less than doing just about anything else.

In his recent post about Mew and RSVs, Tangedyn wrote “Increasing the number of iterations by 100 times to 1million will reduce the Error by 10 times, to ~0.015 requiring 0.0212 difference in RSV, which is far more acceptable.” That is a lot of iterations. In this post, Tangedyn elaborated on the time involved in calculating RSVs: “Takes about 2 hours to test a profile with 1M iterations :/.”

In case you have never done it, download Mew, grab a profile, make sure that the model selected is “Simulator”, and then do two runs, one with RSVs enabled and one without RSVs. You will quickly get an appreciation for how time consuming it is to calculate RSVs. While most people would agree that anything that is extremely time consuming should have a decent return on investment, I hesitate to say that about WoW players who will spend hours upon hours farming for a rare pet. However, RSV calculations do not reward us with a pet. Do they reward us with increased understanding that will help us gear better and conquer the content faster?

Let’s do a few tests and see. First of all, I am not going to do tests with 1 million iterations. I will use 40k iterations (which is still pretty slow). My goal is not to calculate a set of RSVs that can used for my gearing. Rather it is to try several tests to see how how RSVs change as I move my secondary stats around and to draw some conclusions as to whether or not the RSVs can help increase my dps. In my previous post about the homogenization of the secondary stats in 4.06, I already took the position that the difference in the secondary stats is not that much since the 4.06 changes. That would argue against spending time worrying about RSV values. Lets see if that holds true or not.

The setup I am using is starting with a balanced stats profile – Weapon DPS: 703.5, Strength: 142, Agility: 5118, Attack Power: 887, Haste Rating: 936, Hit rating: 604, Crit Rating: 954, Expertise Rating: 188, and Mastery rating: 1987 (this is an ilvl 362 setup). The testing is based on the 4.1 Berserk along with the Berserk changes I covered in my last post. I am not going to make an effort to reforge to different setups, rather I will simply subtract and add to my secondary stats in multiples of 100. For example, I might lower haste rating by 500 and increase crit rating by 500 if I want to test a profile with more crit. The first and most important thing you need to understand about RSVs (other than it can take 2 hours to get numbers that have a high confidence level) is that RSVs are calculated in a small range – about 100 stat points (I move around 91 stat points when I reforge my ilvl 369 chest). If you reforge more than a single piece of gear, it is likely you are changing your stats around more than the RSV code has tested. Enough discussion  – let’s see how different things affect my RSV.

Does the type of fight affect my RSVs:

Fight Description DPS Str Agi AP Haste Crit Mastery Hit Exp Error
5:00 Patchwork 24090.3 2.31 3.04 1.10 .81 1.02 1.19 .99 .98 .08
5:00 Mid-Combat Ravage 25133.7 2.40 3.16 1.14 .86 1.05 1.19 1.03 1.02 .08
5:00 Atramedes 19900.9 1.89 2.50 .90 .61 .84 .97 .89 .89 .07

Across all thee fights, taking into account the error (.08 x sqrt(2) = .11 and .07 x sqrt(2) = .10) we can safely say that haste is the worst stat for my profile on all three fights. It looks like mastery is the best on all three fights, but on the Atramedes fight we cannot say so with a 95% confidence without doing more iterations. It also looks like hit and expertise improve relative to the other stats on Atramedes, but again, we need to do more iterations to have a 95% confidence interval. So fight type does seem to have some effect on the ordering of the RSVs – but not a lot (obviously a fight like Atramedes has a statistically significant impact on all of the RSVs due to lost combat time).

How about the length of the fight?

Fight Description DPS Str Agi AP Haste Crit Mastery Hit Exp Error
5:00 Patchwork 24090.3 2.31 3.04 1.10 .81 1.02 1.19 .99 .98 .08
3:00 Patchwork 24673.0 2.34 3.10 1.11 1.21 1.05 1.19 1.10 1.09 .11
7:00 Patchwork 23977.9 2.31 3.05 1.10 1.03 1.03 1.18 .98 .98 .07

Look at the variation in haste. Even with only 40k iterations per sim run, that is significant. Haste is clearly sensitive to fight length – and in a way that is not obvious without doing more tests. It looks like hit and expertise are more valuable on a short fight but we cannot say that with a 95% confidence – so more iterations are needed to validate that.

What happens if I switch to Glyph of Berserk in place of Glyph of Tiger’s Fury? The previous tests were run with GoTF. Lets try the three fights with GoB and see what happens:

Fight Description DPS Str Agi AP Haste Crit Mastery Hit Exp Error
5:00 Patchwork 24000.7 2.29 3.04 1.09 .90 1.03 1.16 1.04 1.03 .08
5:00 Mid-Combat Ravage 24878.5 2.37 3.12 1.13 .85 1.04 1.16 1.04 1.02 .08
5:00 Atramedes 19948.2 1.89 2.51 .90 .59 .85 .97 .81 .81 .07

Comparing the GoB numbers to the GoTF above, it looks like the difference is not that great – at least for these three fight scenarios.

What if I move around stat points, taking from the lowest and putting them in the highest? I am going to focus on the 5:00 Patchwork fight where Crit is clearly better than Haste – so I am going to shift points from Haste to Crit and see what happens. Technically, Mastery is the better than Crit, but in my actual reforging I am already maxed on on Mastery.

Fight Description DPS Str Agi AP Haste Crit Mastery Hit Exp Error
5:00 Patchwork 24090.3 2.31 3.04 1.10 .81 1.02 1.19 .99 .98 .08
5:00 Patchwork, move 100 24097.7 2.31 3.06 1.10 .95 1.03 1.19 .96 .95 .08
5:00 Patchwork, move 200 24096.1 2.31 3.06 1.10 1.04 1.02 1.20 .97 .96 .08
5:00 Patchwork, move 500 24083.8 2.31 3.04 1.10 .97 1.01 1.21 .92 .91 .08

Once again Haste seems to be more volatile than the other stats, with some movement from Hit and Expertise, although more iterations will be needed to say that at a 95% confidence. The main thing to look at is the DPS line. I shifted 500 stat points from Haste to Crit (ending up with 436 Haste Rating and 1454 Crit Rating) and along the way, the range of the DPS varies only 14 dps from the high to the low. So even if, after a two hour run we can safely say that Crit rating has a higher RSV than Haste, does the potential 7 dps gain from moving 100 stat points from haste to crit justify the time spent?

TLDR: To get valid RSV values takes hours of simulation work. RSV values are only meaningful in a range of 100 stat points. Haste seems to be the most volatile stat (quoting Tangedyn from this post: “I’ve seen Haste’s RSV fluctuate enough that there is probably more than meet the eye, but at the moment there is no real proof pointing to anything as a cause of the the fluctuation or a Haste breakpoint.“). Even large swings (500 stat points) in how you allocate your secondary stats will have very little impact on your overall dps.  Quoting myself from my Homogenization post “The secondary stats are so close in value now that you you can pretty much choose any combination of crit/haste/exp/hit without significantly impacting your dps.” Bottom line – RSV calculations may be valuable to theoreticians, but do not use them as a guide for how to reforge your gear. As always, your time will be much better spent focusing on the fight mechanics and your rotation.