The direction a golf ball starts is related to clubface orientation at strike. The shot shape or curvature is mainly based on the swing path or direction. Having trouble with hooks and slices or pulls or blocked shots- watch the following video.
Posture is about balance. Balance affects swing path. Early extension...too much lateral slide...falling backwards and scooping...leaning forward and steering are all ailments of a body out of balance
We could talk all day about impact and the clubface and where bad shots come from. Understanding and working on the 430 entry path will help eliminate a lot of those off line shots due to poor clubface control. Here's why...
Pinning the shaft on a true plane through impact and beyond results is firmer unchanged wrist conditions, a nicer neutral clubface and it shows a nice unison of release and body moving together.
The first step to improving your golf swing is understanding what the swing plane looks like from the golfers perspective. There is already an up and down built in because of the way we view the ball from the address position.
Truth be told the biggest swing fault for the poorer golfer is misunderstanding swing plane- hand path- clubhead path and how they relate to the target line. They tend to come over the top and slice the club across the ball.