A good loop is one that is oval and aerodynamic. A bad loop is one in which the line way too wide arc and falls defectively over the river. The Tailing Loop or knot wind, is a loop where the line crossed or bass line collide.
When I fish with a long leader I tend to open a little loop, sometimes too, and then get a cross shot which sometimes is very effective fly drift because with a straight shot fly tends to be dredged immediately.
I always try to do good loops when I'm fishing. It is very useful. For this whenever I go fishing try where possible to improve the "reach cast" and "curve cast" making some loops or too open or too closed. The interesting thing is that the curves of the line to be effective cast for fishing. In a few words: what interests me is that the artificial fall in the right place and later as possible in carrying out dredging.

I have a friend who is a great trout fisherman. No day leave empty the river. When we went fishing together, almost always catch more trout than me. Toni effected a horrible cast, a No Loop. His cast rare time pass 10 mt. He cast with the wrist, while the arm remains idle. When he see a trout rising, Toni has to brandish his rod a lot of times on the fish for finally place the fly where he wants. However in the river where fishing get a huge amount of catch, because as anyone knows and knows well about the fish approach. The problem comes when Toni has to fish in rivers wider, with long and quiet waters and deep wells that do not allow fording and force fishermen to cast longer or very long to put the fly where the rising are.
Here comes the real problem and has to settle its shore fish thoroughly. It is well known that most fishermen tend to cast to the other side, because there is a belief that the best fish are on the opposite bank. But we all know that trout are spread evenly across the river, although there are much better than other places. Those sites ambushers, with fallen trees, hard to reach or inaccessible by the other side that is absolutely covered with brambles and all kinds of thorny bushes ideal for drilling the best waders are ideal for our fly falls on the surface and a trout catch it .

I like much fish as much as casting with a fly rod, which is why I always try to be good loops and improve my casts.
There are days that trout are baited with no apparent hatching. a single fly is not seen on the river but the fish are attacked mercilessly, and some of them constantly.

... I get to see that this is a splendid fish, but imitation rather than change with it do not bites. As much as we look Toni leading the current did not get to see anything. Neither up nor in the aqueous film. If we ever see any indication, it is nymphs and larvae, almost impossible to tie any unidentifiable hook size avaible in the market. It is often small black flies almost impossible to build on a winch assembly. However some of these fish end up being cheated in different ways, either with small or tiny nymphs emerging. The fish is well aware imitations we present and in the end one or the other eventually succumb to deception.

We fished at a considerable distance from each other. In the afternoon, Toni approaches and asks me where I fish:

Hi, how are you?-.

Surely you've caught more than me !, I answer.

I've caught five !, tells me smiling.

What?, Five? ... I managed to fish three.

The truth is that I'm very tired of changing flies.

So if you do not fish, what hells are you doing?

... I'm making loops.

~ Carles V.