You know, I would complain mightily about just how HIJACKED this topic has gotten ... if I hadn't cooperated in the hijacking myself...
But I still think that a figure-8 is about the most complicated knot a cord can tie all by itself. I've gotten overhands and figure-8s once in a while with every slinging style I've tried. It does seem to happen more often with overhand casts (Nwmanitou/figure-8/tennis, but almost never with Apache).
Unsapien, did I understand you to say that your sling knows how to tie a figure-8, but you have never seen it do an overhand?
TS,
My friend the Punmaster has a paper Möbius strip, that has the following written along its length:
"How do you keep a topologist busy? See answer on other side."