i guess what TC said is about fair, species dependant, no shocking, no fast slide, perhaps a lil less. Sometimes extra lines or shared upper anchors (in series or 2/1) up around that point.
i generally prefer natural crotch. High friction, means friction is holding part of the load, so less pull on the only variable (of anchor load formulae) on no shock, hanging loads on single anchors; so less anchor load.
You can't prestretch the line before cutting as well with frictional redirect, for the line on the load side of the frictional anchor is isolated to some extent from the control leg. So pulling the control line to pretighten through the fricition, doesn't really pretighten the load leg very much, that really matters.
But, in trade, if you can get the slowly hinging load to prestretch the line as it sinks, then that short segreagated piece of line is all that has to be stretched by this self enacting motion. So, with high friction (wrap) on anchor there is less anchor load, the load can be made to spread out to less leveraged pull on the anchor, and the self tightening action only has to take the slack out of the short segment of line. i release the friction wrap remotely between loads and for removal of line with sling(s)/biner(s) sets or for longer or to ground remote control with a biner on rope, the biner through the wrap to tighten by sweating in, and release for pulling line up.
This is why i asked in Sherrill forum if any one ever tried a PortaWrap for high frictional redirect, without cambium damamge threat.
In lifitng the pulleys rule, as now the friction buffer between the 2 legs of line now puts more load on the anchor, as it has to overcomne the friction before working on the load.
That is; IMAO
