here's a couple of web links I thought were interesting.

the first is to the hunting guide who is telling would-be hunters to go home and improve their accuracy. although he doesn't say it, I'm pretty sure he doesn't really require people to hit a quarter at 20 yards with a bow & arrows. but I think his point is that if people can get really accurate on a stationary target, then in a real situation they should be pretty good for hitting something the size of a saucer. which would give them a heart shot, or worst-case a lung shot. so the animal is coming down, and the amount of tracking is not too big. I'm just guessing this is his real rationale, because he doesn't spell it out completely. most of his article is about the virtues of using heavier arrows on wild boar (750 grain arrows, or thereabouts).

http://www.boar-hunter.com/articles/article/7379302/138283.htm

the second link is a very interesting set of articles on blood trailing wounded game. it is set up as an interactive experience, so you can match your own judgment against the authors.

http://www.bowsite.com/bowsite/features/bloodtrails/

Pete2