To improve it, just ...
This knot hardly needs improvement, it is almost one of the best self holding knots that has been around for a very long time.
It was only a polite way, to say that, as it is shown in the picture ( meaning, without any improvement ), it is probably THE worst
supposedly "self holding knot" I know ( the nub of a
fig.8 knot grips the penetrating line less tightly even from the nub of a simple
overhand knot, because some of its gripping power is "wasted" within its two-collars "8" shape ...) - and the fact that it "
has been around for a very long time", is only another indication of the low quality of the knotting "traditions", and myths... Of course, if one uses a fig.8 knot only as a mere base, re-tucks its tail a number of times, and then drives the penetrating line through another, more convoluted path inside its nub, he may find something better...
However, I believe I have tried
all the possible improvements, but I have not been able to discover something more satisfactory ( = gripping the penetrating line more tightly ) than the "self holding knots" based on re-tucked
overhand knots ( so, based on the double overhand knot, and
not on the re-tucked fig.8- or the re-tucked fig.9-based knots ), as shown in (1). The problem of how to grip a penetrating line, without forcing it to follow a too-convoluted path ( because, in this case, the knot may become self-locking, but it will not remain easily adjustable ), is very interesting, and still open. I believe that the most important property of any satisfactory solution is
the angle the penetrating line is forced to follow as it enters inside the nub of the "self holding" knot : an angle close to the right angle is probably the optimum.
I use to call such an L-shaped, almost right angle deflexion of the penetrating line a "handle", and I try to built on the very effective way the "holding knot" retains its grip on it, even in the case of adjustable loops. ( For the most tight adjustable loop I know, based on a Pretzel-shaped "holding knot", see (2)). The way the penetrating line enters in the nub of such a knot, from its "side", reminds me the way the returning eye leg enters into the nipping loop of the "Eskimo" bowlines, so I also call such adjustable loops
"Eskimo"-like loops.
1.
http://igkt.net/sm/index.php?topic=2996.msg17841#msg17841 http://igkt.net/sm/index.php?topic=2996.msg17842#msg17842 http://igkt.net/sm/index.php?topic=2996.msg17843#msg17843 2.
http://igkt.net/sm/index.php?topic=4464.msg28357#msg28357