This past year I've noticed something unusual in my shooting. I've always had to work through my left (off) eye wanting to take over at times. I'd just squint down a bit when I'd notice it happening and usually it's at times when I'm not well rested. Happens to many I think. Anyway, what's been interesting is it never seems to happen with my SxS guns. They are dead-on centered on my master eye. It's not a matter of my thumb on the forend obscuring the bead because I don't hold my thumb that high. I do know I can shoot my SxS's much more naturally with no squinting required. Is it because the slim horizontal profile gives my off eye no traction? Whatever the case it tends to make me stick with my SxS guns these days.
