I can't recall if this changed in 1.6.3 or earlier, but I know it wasn't in the original as my character copy had spell critical % on her gear.

When I logged into the pts yesterday, made a v14 template, and was looking through skills I noticed that all skills/abilities/gear now use spell critical rating (instead of %) but the character screen still shows spell critical %. Curious to find out how much rating/% was needed I did a few quick calculations.

base spell critical % is 10%.
2pce Aether = 664 spell critical rating = 13.2%
3 pce Aether = 1328 spell critical rating = 16.3%
Inner Light = 2099 = 20.0%
5 pce Aether (light armor Prodigy skill) = 3427 spell critical rating = 26.3%
5 pce Aether + Prodigy + Inner Light = 5526 spell critical rating = 36.3%
*note I am adding up the spell critical rating from tooltips/gear as it isn't displayed on the character screen. Prodigy = 2099 spell crit rating, Inner Light = 2099 spell crit rating)

So, rating/% is: (spell critical rating/% spell critical gained)

664/3.2% = 207.5
1328/6.3% = 210.8
2099/10.0% = 209.9
3427/16.3% = 212.1
5526/26.3% = 210.1

I expected them to be the same value. You need x spell crit rating to gain 1% spell crit.

When I saw the beginning of the trend I thought that it was increasing the rating needed for 1% spell crit the higher your spell crit/rating was, but that trend doesn't persist at all. I know they are quite similar and we could say it takes "about" 210 spell critical rating for 1% of spell critical % but it would be nice if we had the formula for this. Is this variation intended?

Anyone else have thoughts on this? Perhaps EU players with more spell critical gear to swap around to get more numbers...