So, I've been using Premier Pro for 15 years now, and you'd think I'd remember, but I still get confused with the Position Controls in Effect Controls.
I should remember that the numbers on the left are for side-to-side, and the right is for up and down, but I ALWAYS get them confused.
It would help me a lot (and I'm sure a lot of others) if we had little arrows showing the direction the values would move the picture. See sample (red used for effect).