Impact is the moment of truth. All the greats had the same impact position. These are a few things said about impact by golfers, announcers and instructors. We have Impact Fix. But I think the world is full of slicers because impact is only HALF a Hinge motion. The intent of the whole Hinge action (Horizontal or angled) includes its appropriate motion and finish swivel (Educated Hands) not merely squaring the clubface onto the ball. No wonder everyone slices the ball. Add to that the bias to teach a swinging motion, yet only to impact. There is a lot to the stroke after impact. As Lynn said- You got to “prepare,” and it starts at the top.
Look at 12-3-0 Mechanical Checklist for All Strokes. There is no impact point number but a section that includes (36) the clubhead lag and its approach, (37) an online uncocking, (38 ) an online release swivel (39) ON LINE HINGE ACTION (40) Extensor Action, (41) Finish Swivel.
Start looking at impact as an online motion through the ball and straighten that banana ball. Just another reason TGM is the right things to teach and learn.