To piggy back on @JB's thread on a rule change the one that I would change would be to make divots ground under repair. Hit a perfect drive right down the middle of the fairway and wind up in someone's divot-no good. I know there are some that will say rub of the green but it just doesn't make sense to me. I mean if you can repair ball marks on a green, which is basically a divot-why not get relief from the fairway?