This photo is facing north in the Colorado backcountry. Wind is coming from the west. You see a buck or bull step out into an opening 850 yards below. You estimate the wind is about 3-4mph at the target. Let's say you have a 9 gun. This means that in a 9mph wind you have to hold 1 mil of wind. Since the wind is blowing half that (3-4mph), you need to hold half of a mil (.5mil) to the left (West). You ensure your body is relaxed with the weapon at its natural point of aim, you glance up to check the bubble is level, you breath air out of your lungs while apply gradual trigger pressure, once your lungs are empty you pause, continue squeezing...that's one of the moments hunters live for, small but exciting moments of cherished opportunity.