After extensive retesting today in Cyrodiil with my wife, I have obtained the following data and come to the following tentative Spell Resistance/Armor and Spell/Armor Penetration formulas. These are different than my previously derived values. Note, this is still a work in progress, and I'm currently not sure how to properly reconcile the small differences in my estimates vs my actual numbers. The premise and scaling should remain constant for extrapolation of optimal DPS setups.
http://imgur.com/RXqTaqN
Damage Multiplier = 1- (TRUNC((RESISTANCE - PENETRATION) ÷ 63000),2)
While the numbers are not posted here, Focus Rating is increased by the raw Spell Penetration % listed in a the Apprentice Constellation (+5% increases pen by 5, 12% by 12, etc). The Apprentice Stone increases Focus Rating by a set 3200. A Sharpened Weapon increases Focus by 240%.
Edited by evedgebah on 1 March 2015 20:02