JudoP wrote on Jan 21
st, 2021 at 8:56am:
My instinct is that more pliable slings work better with fig-8 because of perhaps a larger and more complex rotation from the hand which would be inhibited by stiffness. Stiffer slings also tend to be heavier and figure 8 for me is a higher speed lower force motion than balearic sidearm for example.
I disagree. If you have a stiff sling, it resists rotation around the strand axis. If you get this rotation, you get crossed strands and the release cord gets tangled around the retention cord. No bueno. You want something that resists twisting so the force applied during the wrist motion is transferred to the projectile almost as soon as it is made (ideally simultaneously).
I think in terms of following wrist rotation, which occurs with any throwing style excluding maybe Apache style, we can objectively say that a retention cord that resists twisting is best, regardless of throwing style.
In terms of a quick release, and the sling cords not interfering with the projectile, a very flexible release cord is best. At least flexible in the sense that it can have a small bending radius of curvature to facilitate moving the release cord out of the way of the projectile as quickly as possible.