In the version of the Blood knot I tie, the wraps are only around the opposite SPart i.e. a single diameter.
This is one way to
tie the knot, but if made in the usual materials for it (i.e., in
some fishline), the successive turns of the SParts will move out into the wraps
of the end and result in the form with wraps around the opposed SParts. (In Barnes's
terms, "outcoil" & "incoil" tying methods.)
Other knots such as the carrick have a greater symmetry
Let's not get tricked by the name: with the Carrick, there is usually the
open,
lattice-like form shown as a way to tie it (sometimes it is tied by forming a kind of
crossing knot (aka
Munter hitch) in one side into which the other rope is tied),
but the usual capsized/collapsed form which is only singly symmetric.
*knudeNoggin*