I recall when I first started playing that I would sometimes close one eye to make sure my dominant eye had my cue on the proper shotline. It's easy to tell if you're offline. And it may help you build a straighter stroke, unlike my shoot and holler sh** stroke.When I started doing the Mighty X drill I often got a perfectly still CB, albeit one that is spinning counterclockwise. I know I have a perception problem where I hit the CB ever so slightly right of dead center. I never would have realized that with a plain white cue ball.