This from petersons bowhunting mag. They are basing the reaction time on half of what a humans is. They claim the reaction time of a deer is .05 secs. Sound travels at 750mph and if you were to shot a deer at ten yards or less the deer would drop approx. .5in with a 230fps arrow and with a 280fps arrow will drop almost none. Now here is were you see were speed could help you. At twenty yards a deer has the ablity to drop 5.5 inches with a 230fps arrow and with a 280fps arrow it can drop 2.75 inches. Now at thirty yards at 230fps it can drop or move as much as 16.75in and with 280fps it can move or drop 9.5in. The article goes on to say that 95% of doe will jump the string while, only 50% of bucks?? Who knows ir this is correct but I would bet they are pretty close. I have had 2 deer jump the string a duck an arrow both shots were 25-30yrds. I actual seen what one done I was in the zone and everthing went in slow motion and the deer dropped it hind leggs to the ground and arced her back and right were the arc was is were the arrow went. She wasn't even looking at me when I shot. The other was this year and was another doe.