Resistance mechanics have changed?
It seems really strange that this hasn't been posted before, so maybe my search skills are just weak... I've checked here and at EJ, and haven't found a peep, and since I don't feel like replying to 10 random EJ threads to start my own post, I thought this would be a good place to start the discussion. :)
I strongly believe that resistance mechanics have changed in WotLK. After seeing Sapphiron a few times and watching SCT, it did not look like the right resistance rates or amounts to match our understanding. The most obvious piece is that partial resistances are not in 25% increments anymore.
I did some preliminary testing with a warlock last night, wearing different amounts of fire resist and having searing pain spammed in my face for 200+ casts. 200 isn't perfect stats, but it's only got about a 7% error on the results, which is plenty to see that things are different at the top end.
The resistance values I tried were 0% (short test, no partials as expected), 130, 215, 414, and 460 on a hunch. The hunch wasn't so conclusive, but these are the resist values I saw:
0 resist was 0%, really. I didn't see any partials.
WWS Loading... 130 FR - 25%
WWS Loading... 215 FR - 36%
WWS Loading... 414 FR - 52%
Wow Web Stats 460 FR - 55%
I fit these %s in Matlab and it fit best to a cubic poly, but I don't think my sample sizes were large enough to say that for certain, or give the formula. However, it's definitely a) not linear, and b) not 75% at 415.
Next I'm going to see what the shape of the partial resists looks like for a given resistance value. I have a feeling they want a much less swingy resist system... Even at 130 resist from just an aura, there are basically no full hits anymore. Check Sapphiron or Loatheb parses for lots of data points quickly.
Also probably of note is that there were no misses on the higher resist value trials. The 130 trial had the warlock completely gearless, so there were some misses, but for the rest she put a few pieces back on to keep her regen high enough to spam searing pain without going OOM. So I don't believe that resistance affects miss rates anymore either, which could probably have rather large implications for PvP.
I also wouldn't be surprised if there is no "cap" anymore, if it's an exponential curve (aka diminishing returns). There's no need for a hard cap with a curve that places high resistance rates out of reach just by availability and budget cost alone.
I'll get more trials at various resistances and see if I can get a likely formula out of it, but I wanted to start a discussion and see if there had already been work done elsewhere that I just haven't found yet.