IMLHO (disclaimer), in these things we are dealing with a dance of raw forces in a given situation, and the strings of multipliers that are involved. Each variation in the setup, varies a handful of multipliers, that can change everything. Even if the raw forces are fairly matched in separate situations, it is the multiplying forces that dictate if the raw forces are then conducted at nominal or full potentials. Thus, different experiences and comfort levels from different peoples.
The angle of the line gives a multiplier above 1 here usually(multipliers less than 1 reduce forces, less than 0 reverse their directions). But, then we also lose the perpendicular/ more leveraged angle of the line to the tree, in the formed direction mediated between the 2 legs of the angle, and not just along a single leg pull line. Which is better, will then depend partially on the leveraged increase from the rope angle multiplier less the leveraged loss of the pull angle change multiplier(how it is more down than across now).
But then also, the amount of friction at the angle of line, will reduce that angle's potential force by decreasing the tension on the far/anchored leg. But, then, this will give more of a direction of pull perpendicular, more along the pull line than less. But, then by sweating more purchase(elusive, invisible quantity that can be very important) out of that leg b4 the main pull, we can reduce that reduction. Perhaps even reverse it, by stashing tensioned line back there behind the friction buffer??
But, then that brings up another factor, elastic deformations. We now have more rope to store tension in elastically to later release, and perhaps can flex/spring our prey/target; to let it give same re-leseable force characteristic like the stretched rope too. It all adds up... Which would then include moving the tree's CG more leveraged towards target(if we flexxed tree), all in the pre-start. Hear especially, you could even have a contest ready to go, side by side(let alone across the map), and 1 setup has so much more potential captured. This shows paint prep (and experience) that 1 man might do most meticulously(and another not) polishing each point to smooth perfection of focussed, unfettered force. Or at least knowing what alterations where needed , and which yielded the most for your time and trouble.
Noting that even if the direction of pull across the spar was now less, the force from the bend would be increased, and the more loaded forces would move more surely to target, even if not a lot easier force wise on every occasion. This alone can be a big thing, especially with the inertia of that now moving force.
i also think that if the spar is straight (not the Dano version; whereby that is a different machine, with an extra bend), the line down the back spine (and compression) can be fortifying, also kind of push/brace forward as the line cradles the load with even a more of a 'rolling forward' motion. Especially more noticeable with a more closed angle, across pull, and serving forward with everything else against ye, of a back leaner. And then in reciprocal, less noticeable as we have a straight, then even less in a forward leaner (where friction reduces, but angled force does too, and direction is more straight down than across). Sometimes each strategy will be best, by what effect is needed.
Notice even if we hung tree upside down by this bend, the bend would have increase force over that of the tree!
Also, the knot is easier to find tied low back, and is not buried, is closer to a team member, and employs that member that might be closest to taking a break, leading, caring for lines - the sawyer.
The line doesn't have to come straight down on this rig. We can even tie low, centered-back to go high right, then low left in front, to offset to the left as we also serve forward, with our direction factor. This can be more of a closed angle and sometimes solicit more elasticity/spring from the top too.
A lot going on hear, i recommend everyone get fluent with the feel of this orchestrations of forces in felling, rigging, pulling tops out etc. Play as with a new toy in open wonder, harvesting occasions to do so, as they offer themselves. L-earn them, polish their deploymeant, then finally, holster them when confident you can draw them out quickly and sharp shoot cleanly when called for/equitable.
This, all then too, depends on the mechanics of the hinge/pivot itself, to once again; make 2 totally seemingly same situations, much different by their orchestration, sometimes fairly invisibly. but, giving higher, safer, more confident, less effort success rate.
