p 152 "The Outcomes Table" which details 8 different degrees of success or failure.
It is calculated after every opposed roll. Which is basically every attack roll in every combat, constantly in flux based on if you failed to gain advantage that round, get outnumbered, spend it to disengage, have skills or talents that change it, and probably a host of other situations. Do I track this for enemies? Along with wounds, armor ratings, toughness modifiers, lingering injuries, etc.? I don't want to have to keep a spreadsheet to keep up with this stuff.