From Lutcikaur, the person who calculated the weights in my guide:
I ran an effort function over a set of assumed stat values, compared their scores and used gaussian elimination to generate stat weights.
Targets 12 | Burst true | PreAtone false | Atone 0.65 | Dur 15
int 0.889 | crit 0.703 | haste 1 | mast 0.712 | vers 0.673
(Note: the weights may be different than in the guide, some of the variables were different in the response he provided me. Use the weights located in the guide itself.)
The general assumption is 65% or more of your healing will come from Atonement. The calculation itself came from assuming how many Atonement's you would get out (generally 12-15, for the calculation 12 was used but Mastery's weight would increase the more you have) and how many casts (LW, Penance, Smite, etc) you could do during the remaining duration. In order to maximize your burst, Mastery takes the lead over Crit because of the total percent of your healing coming from Atonement, and the fact that it gives you the most bang for your buck in terms of Atonement healing during that window.
Last edited by MendUS; 2016-10-16 at 03:33 PM.