Tailing loops are very frustrating. Some of us suffer them mildly once in a while, for others it is a chronic illness. I know of an experienced fly fisher that produces a tailing loop almost on every cast. A fellow angler told me not long ago that I was obssesed with tailing loops. That could be the case, but I don’t mind. I am interested in tails because I see them recurrently in most of my classes, and think that the more I understand them the more effective I will be in helping to cure them.
But my fellow could be right, why to focus so much in tails? Are they that bad? Those big enough to cross legs are prone to knots, and a wave big enough can send the fly to some unexpected places during the presentation… but probably only if they are combined with the legs of the loop being in different planes. More subtle tailing loops —specially when both legs share the same plane— are probably harmless most of the time.
But guess what? I fly fish due to its esthetics, and a straight fly line unrolling is a flying beauty. That tailing loop above is the exception that proves the rule.