I guess my experience is all over the place....I have had bow shot deer walk off like nothing happened and fall over 15 yards from the shot.
That being said...I shot a little spike that ran full tilt for a 100 yards with a good heart shot.
I don't even want to talk about my rifle hunting experiences...
You just never know what a deer will do after the shot. I've had deer just jump up and then look back at the arrow sticking in the ground, and I sat there and thought I had missed until the deer turned and started to walk away and began to wobble, and then fall over dead.
I just shot a spike buck the other day blowing up it's heart and it bled buckets of blood and still ran about 60 yards before piling up.
You won't know until you hit one, and the only thing you can hope for is a clean pass thru, and a lot of blood.
A broadside or slightly quartering away is ideal, but try to avoid a deer quartering toward you with all that shoulder bone structure in the way.