a mistied version that works
The comments on this thread were interesting enough I decided to try the mistied Blake's for myself: sure enough, as everyone agrees, it sucks. I agree with Gasman, the mechanics seem to be all wrong.
However, when I added another wrap at the top, the mistied Blake's worked fine. Then I tried another variant with only 4 wraps that also worked fine. I will try to post pictures tomorrow, since I know I can't describe it adequately.
I think the single-legged friction knots like the tautline or Blake's are inherently inferior to the two-legged knots like the Schwabisch or Distel or Martin's. Mechanically speaking, loading both legs of the knot seems to distribute the load better though the knot and produce more reliable and predictable friction. These knots seem to relax better when unloaded, making them easier to slide up the rope. If it is true that the friction is distributed more evenly throughout the knot, this might help to explain why they relax better. No part of the knot would have to be particularly tight in the first place, unlike the one-legged knots, and the knot relaxes from both ends as the load is removed from both ends, also unlike the one-legged knots.
Other factors are involved, like materials used, but it seems to me, all other things being equal, the mechanics is way better for the two-legged knots.
