[King Prout]

not as "duh" as all that - ya gotta know WHY one end should be up before you make a decision. tapers and proportions, mannn...

[NicknamedBob]

Ah, yes, of course, but then, it is asymmetric, is it not?

One wonders if this is to give a slight gravity defying flick upon launching, so as to negate the effect of the arrow "falling" for that millisecond in which it is traversing the bow.