Yeah, nice site, that... I remember watching a few videos online that used it to further explain some damage calculations.

As for what determination does, I'm still going to repeat (yet again) what I have been suspecting since the beta days... I still (very tentatively) think it has something to do with how often you can get a Proc. Weird as it may sound, after looking at several variables, it seems quite plausible that it possibly affects the frequency in which Procs pop up for you in battles

/Shrugs... guess we'll figure it out eventually