I’d rather people look up parallax themselves. Too complicated for me to attempt to describe it here.
What I did notice is that if I lined up center ball (center vertical and center horizontal), then move the cue tip to the bottom of the CB the tip was actually slightly right of where the CB touches the table.
So I repositioned my head so that center really was center. It has helped with unintended right spin.
Mind you, over time, it went from very concerning significant right spin to *barely* rotating counterclockwise on dead straight shots, if at all.
It’s still a work in progress.
Lately something that has helped with potting accuracy and eliminating unintended spin is to stand back much farther from the table and make a pronounced step forward into the shot bringing the cue down on the shot line, rather than stand and bend over with minimal forward motion.
Problem is that some places I play don’t always have enough room to step back then step forward into the shot. So I have to be even more cognizant of my feet if I can only take a very short step in, or even no step forward.