1) Align a perfectly straight, long shot, with some distance between cue ball and object ball
2) Get down on the shot in your usual stance
3) Does the shot appear perfectly straight to you? Acknowledge that fact, now move your head laterally to the right or left and inch or two (move your head sideways with your neck and torso rather than swivel your head). Note that the straight shot appears to now be an angled cut shot, causing you to add human error to the shot from here.
The "vision center" or "alignment spot" is where the shot looks precisely as it appears in reality. A consistent head-eye position, particularly the position where the straight shot looks straight, is needed for each and every shot, cut or straight.
For the OP, my original questions remain. I can help them get down on the shot without undercutting to begin, but I cannot fix a stance (safely) without more information.
2) Get down on the shot in your usual stance
3) Does the shot appear perfectly straight to you? Acknowledge that fact, now move your head laterally to the right or left and inch or two (move your head sideways with your neck and torso rather than swivel your head). Note that the straight shot appears to now be an angled cut shot, causing you to add human error to the shot from here.
The "vision center" or "alignment spot" is where the shot looks precisely as it appears in reality. A consistent head-eye position, particularly the position where the straight shot looks straight, is needed for each and every shot, cut or straight.
For the OP, my original questions remain. I can help them get down on the shot without undercutting to begin, but I cannot fix a stance (safely) without more information.