Lots of things to consider, other than what's been stated already. First I consider the approach distance, is this a long or short iron. ( shorter irons will give you more back spin.) Green speed, faster greens are harder to stop a shot on the green. Elevation, how much added yardage is needed, and finally, wind speed and direction. Now, a long iron shot, say 190 yards, with a tail wind of just 6 to 8 mph, 10 speed green, elevation of about 20 feet, I can guarentee that if you aim at the pin, your ball will land on the green, roll all the way to the back of the green, to the rough, like you landed on ice. Elevated greens are always harder to stop a ball with backspin, espically with a longer iron, learn and note it, hit a shorter shot than you figured. Sometimes I figure as much as 15 feet, shorter, to account for roll out. Good luck, and better shooting to you.