My assumption is that weapons have their crit chance per tick/strick, lets say its 10% (I know that's not the real value).
Now you pump 5 points into -crit chance to get -5% chance to get critted.
I'm willing to bet the way they implemented is is that your chance isn't straight subtracted but that it's the 10% gets 5% of that chance knocked off so its more like a .5 reduction instead of halved like you'd assume it was. Much less if the incoming chance is less, so it almost becomes a meaningless stat.
Can't see them doing it any other way otherwise I think you'd be able to completely nullify or very nearly nullify crit chances.
-- sorry about the title misspelling, its been a long cloudy day without nearly enough coffee to boost my morale.
Edited by sycocys, 18 May 2017 - 10:07 AM.