My understanding is that any golf club (except putter) can ONLY put backspin on a ball. A ball curving left or right is still backspinning, but on a tilted axis.
If you reason that face angle and path determine whether a shot becomes a draw, fade or straight then you can apply the same logic to backspin/topspin.
The ball hasn't got a clue which way is up, only how it is hit.