Holland and Holland's "The Better Shot" goes so far as to suggest that persons with wide-set eyes tend to crossfire because in tilting the head just a bit to the stock, their left eye (for right handed shooter)is elevated and picks up the target an instant faster, thus being the faster to focus.
I have a cross dominance tendency. I shoot splinter forend SxSs. With my left hand I grip the barrel with only one or two fingers over the forend. I grip it in such a way that the fat part of my (left) thumb just barely blocks out the end of the barrels to my left eye. It does block some sky from my right eye but I believe that what I give up in sky is more than made up for by completely eliminating my cross dominance tendency.
Best,
Mike
