Another, more symmetric, Double Constrictor

[knot4u]

You need to show that knot loosened up or something.

[xarax]

   The riding turns in the back of the pole are "parallel", do not cross each other. ( If It were otherwise, I would have shown the "back side" view as well). See at the second attached picture, where the bulge of this snake s belly - right after it has swallowed its prey (the twisted free ends / tails) - is clearly shown... Is this a new low in knot ugliness ? It might well be, but this knot is a Constrictor-type knot nevertheless. The knot TreeSpyder presented in reply 28, is a different species, I believe.

[xarax]

   It occurred to me that, in the great garden of Knotland, there is some gift for everybody ! I have chosen the younger beautiful Double Constrictor(ABoK#1253) - even if I have to share it with the other guy  -, knot4u has chosen the older, a little lump, but ready to come undone so fast Double Constrictor(ABoK#1252), the TreeSpyder chose a close relative, and TMCD would probably be satisfied with the uglier, a little hunchback, but tight nevertheless Double Constrictor(ABoK#?- reply 28). Because, the "ugly", so pronounced bulge of the later, might well offer an advantage when the surface of the pole is not so convex. This second riding turn, going over the first one and the twisted pair of the two free ends, is pushing the rest of the knot s nub towards the surface of the pole, even if the first one is not - as it happens in the case of a flat(ter) pole surface. There is an obvious asymmetry in this knot, that may be exploited for a good purpose: the one free end, after its embrace with the other, becomes the lower riding turn, and the other becomes the upper one. If we choose as standing end this second free end, ( the one that becomes the upper riding turn, and goes over the other) we can transfer the tension of the pull into the corresponding riding turn more easily - and thus tighten easier this riding turn, that is more curved, and presses the rest of the knot s nub harder toward the surface of the pole. Of course, TMCD is advised to test this theory in flat and slightly convex surfaces, before his final choice. 

[xarax]

... if the double constrictor (#1252) is brought off of the object ...one has then a gleipnir version.

  In a similar but simpler cosmetic operation, the Triple Strangle, if only the two outer coils are wrapped around an object, is turned into a Double "simple hitch a la Gleipnir" (See the attached picture). Or, this later, if brought off the object, and the two riding turns are shrunken to the size of the nipping loop, one has then the "Triple Strangle".
   ( I believe that the Double "simple hitch a la Gleipnir"  is a most tight hitch that can be compared, indeed, with the various sisters and cousins of the Double Constrictor, but this is something than can be proved or disproved only by careful experiments.)

[TheTreeSpyder]

The Dbl. constrictor i normally think of takes a 'linear Round Turn' with Bitter end around input from Standing.
As like a number of such 'twirls' for Timber variations, turns over first rather than under, half hitch with better nip etc. the 2nd 'linear Turn' can help in key positioning for best 'nip'.

i think of Strangle as Dbl. Marl., because of Round Turn 'upgraded' from Turn in it's forging.
Dbl. Bowline presents Turn to Round Turn etc.

In this i just see added Turn to Constrictor.

If the mechanic is in the Constrictor, some of same mechanic would be in added Turn form too?

http://www.mytreelessons.com/ks/other_Double_a.swf

Not really hung on name thang, but rather mechanic; but think naming should reflect that mechanic.

 If there are 8 turns on the road, to next town, and 3 destinations; you wouldn't start directions over each time; just say go to town on such and such hiway, take Left to go to school, but take right to go to market, past the market and right for library etc.  i think understanding and naming should have the same logic as the route directions to next town etc.

[xarax]

In this i just see added Turn to Constrictor.
If the mechanic is in the Constrictor, some of same mechanic would be in added Turn form too?
http://www.mytreelessons.com/ks/other_Double_a.swf

   No. The fact that, if we remove one riding turn, a knot now turns into a Constrictor, does not mean that this knot was the Double Constrictor in the first place ! In short, a Double Constrictor is not a single Constrictor with any additional riding turn, but a Constrictor with an additional riding turn that runs over the twisted free-ends-pair of it.