In reply to john arran:
> Not convinced about #2. I always thought it was the orientation of the rings in a 2-ring setup that was the culprit, rather than their relative heights, the worst case orientation being when both rings are in the same plane and tending to lie flat against the wall.
This is so, a correctly made and installed vertical offset setup shouldnt twist the rope at all. The one pictured needs more vertical and less horizontal offset.
However since that particular brand of hangers and rings are popular in the USA it's not suprising they get twists, the ring should hang from the hanger so doesn't (or barely) touches the rock and the hanger should be designed so the ring has a clear lower point to rest in under load (it should be semi-circular) not a horizontal slot which makes the ring twist when it slides to the end.