For the purpose of this thread, let us accept a most general half-functional ( what a knot "does", as a physical mechanism ) and half-geometrical ( what a knot "looks like", as a shape ) definition of a "knot" :
A knot is any tensioned yet curvilinear segment of a rope, which compresses and is compressed by itself and other segments of ropes. ( So, by this definition, the "open" helical turns "tied" on the Standing Part of a
Helical loop (1), is a knot. They compress the encircled rope segments, and they are compressed by the first/"higher" and second/"lower" collars. They function as a
nipping structure, by encircling and constricting the
collar structure that is tied at the end of the returning eye leg of the loop, and thus enhancing its internal friction, and its ability to remain knotted ).
Let us examine a one-wrap hitch, by following the rope from the start, the Standing End, to the finish, the Tail End.
There are three different possibilities ;
1. Standing End - Riding turn - knot - Tail End
2. Standing End - Knot - Riding turn - Tail End
3. Standing End - Knot - Riding turn - Knot -Tail End
( Same way for the two- or multi-wrap hitches.)
Now, there is another thing we should distinguish : The pole or the ring around which the hitch is tied, in a sense,
is part of the knot itself. At the end of the day, it could had been made by a flexible, lengthwise, material, so it could had played the role of a rope - although not "knotted", according to the definition of a knot mentioned above, because it is compressed, by it does not compress other segments of rope. However, its mere physical presence can force the Knots tied between the Standing and the Tail End to be do and to look like differently :
In particular, it can make two things, or a combination of them :
1. It can force a knot tied before, after, or before and after the Riding turn, to take a particular shape and/or be stabilized in a certain orientation, which is required by the hitch. An example of this is the knot / bight on the surface of the pole of the hitch shown at (2), and at the attached picture : If this knot / bight had not been forced, by the physical presence of the pole, to remain twisted, "on its other ear" on the surface, it would had not be able to nip the penetrating Tail End as effectively as it does.
2. It can force a Tail End to follow a particular path, "under" or "over" the Riding turn. An example of this is the Tail End of the (
Single)
Locked Cow hitch. If this Tail End had not been forced, by the physical presence of the pole, to remain "under" the Riding turn, it would had not been able either to be immobilized, or to "lock" the Standing End.
Now, in the case of some simple hitches ( as in "tight" (
Single)
Locked Cow hitch, but also in its poor relative, the "not-tight" ABoK#1683 ), the fact that the Riding turn is tightly wrapped around the pole, is also required : a loose such hitch can not work, because the Tail End is immobilized by nothing else than going, and been squeezed there, in between the Riding turn and the surface of the pole. In short, a loose tight hitch is a contradiction in terms !
1.
http://igkt.net/sm/index.php?topic=49492.
http://igkt.net/sm/index.php?topic=4975.msg32773#msg32773
