This is a stopper knot that is somewhat bulkier than Ashley’s Stopper Knot and is derived from it. Where Ashley’s shows a trefoil pattern when looking down the standing end, this knot has a four-fold pattern around the standing end.
Topologically the knot is a double overhand noose with a tuck back.
It is easiest to tie without the tuck at first. Tighten up the double overhand knot around the standing end by eliminating the A segment. This will bring the B and C legs together with the standing end inside the loop. Snug this up enough that the standing end is no longer free to slide and none of the sub-loops are loose. The tighter this is made, the more secure the finished stopper.
Then, continuing in the same wrap direction around the B segment, tuck the working end through the noose as shown. Pull the standing end and the working end tight to create the four-fold pattern. In addition to being bulkier, if this knot comes loose there is a remaining overhand knot as a backup stopper.
If this knot already exists, please let me know so I can give proper credit.
I first ran across this charming knot as a bit of decorative graphics on the Contents page of “What Knot?” by Budworth and Hopkins.
The working and standing ends ran off the page so it was not obvious which was which. Unidentified on the page and appearing nowhere else in the book, it piqued my curiosity. It was an interesting looking bend and I spent some time playing with it. It appeared to be very secure, had no tendency to “tumble”, and unlike most secure bends, e.g. zeppelin, Hunter, Ashley, which bring the ends out the sides, this brought the working ends out in parallel alongside the standing ends. With symmetric standing ends it snugs up to a nice slender compact knot. This would be a good bend for passing through an eye. Eventually I discovered that this topology was called a Vice Versa with the top B-A pair (or bottom A-B pair) as the standing ends. I had already discovered that this caused the knot to cramp into a bow and lose its tidy cross-section. Wikipedia came through with the information that this knot with A-A for the standing ends was a Reever Knot. In either version it is reportedly excellent for slippery cordage. The Reever version maintains the compact shape with a slight skew. A nameless version with B-B for the standing ends that applied force close to the center axis and resulted in a neater square shape was my sentimental favorite. I developed a good way to tie it.
Enter the heartless wind of science. I used some 30 lb test monofilament line and tied a bunch (technical term) of these. The Reever Knot locked up tightly and held all the way to the point where the line broke without any slipping. The Vice Versa slipped some and then broke at a similar load. The B-B version consistently slipped completely at a lower load. I used monofilament to discriminate. None of these are suitable for wet fishing line. Abstract:
Reever Great (Now I have to practice tying this.)
Vice Versa OK, not as neat, nor as good for really slick line.
Anonymous B-B Back to the irrelevant tech pile for you.