This was more of a good guess than a good shot, but in the sniper battle against The End in MGS3 I nailed him with a headshot just based on his position on the map. I looked at the map, saw where he was in relation to me, then aimed my rifle where I thought the map was showing him to be and fired. Sure enough he was crouched right there behind some bushes, and that was the last shot I needed against him.