You likely have two issues here. I've seen some strong players turn their head on some shots. It can be a problem with the dominant eye, or simply a nervous tick. Regarding general head movement, this is one thing that clearly separates high level amateurs from pros. Players unconsciously develop a little upward or forward motion of the head, often on particular strokes, like follow. It may be only a slight movement, but it creates the effect of shooting at a moving target. Here are five possible remedies:
When you hit your first few shots of the day, think only about keeping your head still, - gets you off on the right foot.
When practicing, do not give yourself permission to stand up after hitting the cue ball, until either the object ball disappears into a pocket or the balls stop rolling. Jimmy Scrima showed me this method in 1991.
If someone tells you you have head movement, but you don't feel it, have them hold a cue an inch above your head while you're practicing. If you raise up, you'll have proof! My VNEA champ teammates used this method in the '80s.
"Pose" after every shot. Jerry Briesath showed me this method in '72, as part of his "look like a pro, play like a pro" approach.
Take an extra stroke AFTER you strike the cue ball. If you keep your head still for the extra stroke, it virtually has to be still for the business stroke. I like to use this when I'm feeling a lot of pressure.
Donny L
PBIA/ACS Instructor
Gainesville, Fl