tx, consider offset as straight but slightly angled left or right. Okay?

Helical wraps around the arrow, as it says, helical...Offset is a straight fletch that is angled across the shaft surface...the angle causes air drag thusly spinning the arrow.

And forgivie my answer, although correct I would have worded it different had I paid attention to the title, on quickspins I would sooner offset than helical...Blazers as well.