It is very hard to tell if exp gs stamina hca have any influence to this skill. If it has it is very little
Actually I made a study last year that told me that GS, exp, stamina are values strictly related to FT (especially stamina and GS). I dropped the study and all datas for personal reasons, but I saw some relationship among those skills.
I like your effort and your idea, I don't want to criticize you because I like what you did, but I think there are too few datas, you did not consider improvements in FT skill and you did not consider important factors (such as GS, stamina and experience as I said above).