RickRR: Thank you, never thought of using top spin on long irons,
A lot of players don't either, it's all about the exact number. Full back spin or nothing. However, a real golfer understands what happens when you hit under head winds and get the ball rolling. Punches are quite effective for this, especially on the links courses. Don't bother trying to chart something like that, it takes true golf sense to be effective with it because the ground is involved, particularly strategic slopes.
IMO, the best thing you can do is learn the carry of your clubs, not how far they go. Then you can get a true sense of what different spin does. GL.