I like the first crossing over itself for the eye to be against any slight anticipated pull direction; but best is a straight pull.
To me, Timber Hitch is a simple mechanic/art; of like a loose eye splice. But to maximize; the simple mechanisms must be applied precisely, i think you must watch for some things. Then remember too, that it is meant to be loaded in 1 direction and constantly(as pointed out by taller peoples) to maintain it's 'trap' on itself. And all points of contact that 'nip'/pinch the tail must be at firmly convex positions; we are building a quick machine etc.
The direction of pull should be perpendicular to the mount; for this places the back of the hitch inline with the initiating force of the Standing (Tension?) Part. If these aren't inline, i think of the mechanics as leveraged. Also, too; at this angle, and not lowering, you can have a pointed/not flat teepee where eye bends Standing; giving less intense deformity; so less tensile strength loss. The flatter the teepee the more tension forced (like when cinching up tight). So that, on loading the initiating force of the Standing; is leveraged higher by the flatter teepee/ from a more deformed Standing. i think if you know these things; and target them you can throw a positive machine/hitch into use; polishing each point from habit. Side by side, it might jest look like the old guy is just luckier; but what if he is just tucking and aligning right? Notice too, inolder tymes/ 3 strand, the lay of the line too, is a consideration; in fact the line itself is all ways a consideration..
"Ashley's Book of Knots" ; breaks these types of hitches into 2 separate chapters; back to back. Pulls to Rail (perpendicular) and Hitches to Spar (inline pull); i think that is because the mechanical differences are that intense. In general for inline pull with timber, you wold precede with a Half or Marl to make Killick etc.; i think to correct the mechanics, get another grab to secure, make more shock worthy etc.
These few ABoK pages, also show small nuances to maximize. Like, bringing the eye a full/ Round Turn around the Standing 1669( i think of as to firm; and attempt to restabilize somewhat the suddenly destabilized/ altered position of the sudden bend in the loaded Standing/ and the impacts of it's suddenness). Nipping is of more consideration farther away from Standing 1663(closer to Standing is where the securing pinch/nip is less intense, or actually pulls away from spar, notice the skull by 1662 as warning), to the opposite side from Standing (where back of hitch is seating most firmly into spar/mount)coming over, then under 1666, 1668, 1669(which gives both more friction reduction before nip/pinch and places the nip out further).
