Hahaha--no math needed to understand this stuff. It's demonstrable physics using gravity so no computation's needed. The TL;DR version of it is that ideally the handle of an axe should be pointed towards the center of gravity.
Here's a plumb line dropped along the main length of the handle. You can see how it runs along the same line towards the center of gravity, which is what makes it balance well.
I always wore a leather mask when doing my beheading work....that said ....it really was always more fetish based...
Hahaha--generally I don't have a ton of time to do takes and retakes when I inevitably stumble over what it is I'm trying to convey. When I do any speaking I prefer to record it as narration in post-production as a result. Haven't really been able to do that lately, though, as my USB mic busted and I haven't gotten around to picking up a new one.