In general a three blade head should give you a better blood trail but as stated before there are no certainties. I shot a doe once from a tree stand with a 4 blade muzzy. Hit her right behind the shoulder through the lungs. Clean pass through leaving a nice low exit hole on the offside that should have poured blood. From where my arrow was buried in the dirt to where she fell dead 60 yards away I did find a single drop of blood. Just no rhyme or reason to it sometimes.