Specifically I'm wondering, what exactly are the chances of a pokemon with 3 or more affection hearts surviving a fatal blow with 1 hp. Bulbapedia and Serebii both say the chance goes up as Affection goes up, but I can't seem to find out what the actual formula is for determining the chance anywhere. Surely somebody must've looked into this before me?

Well, if anyone has any links or info on what the specific formulas are for determining the chances of Affection effects, I'd be really grateful.