The MOST important thing about the golf swing
Regardless of anything else, the golf club MUST approach the ball FROM THE INSIDE.
NOT merely enough to strike the ball at it’s center, but on it’s inside right quadrant (for a right-handed golfer).
To enable this, there are very many compensatory moves you can use, while starting down from the top of the backswing. You could slide your body towards target. You could drop your trail shoulder backwards. You could arch your spine.... And the list goes on. Your brain will figure out a pattern, to allow you (once you’re a fairly regular golfer) to arrive at the ball ‘from the inside’ - most of the time.
DROP TRAIL SHOULDER BACKWARDS
However, when you are aroused, nervous, in unfamiliar surroundings, the timing, that is the ‘sequencing of body parts’ of your swing might change, and you will not make all of the compensatory movements you need to, to get from the top of your backswing to impact, in the limited time span of your downswing.
The ONLY way to arrive at the ball from the inside without any manipulating/compensatory/re-routing movements is to position your body at the ‘top of the downswing’, rather than the ‘top of the backswing’.
What on earth does that mean? That means, every joint must be placed so it is positioned for its role in the downswing.
So, the TWO MOST IMPORTANT body parts to position correctly are the trail shoulder and hip joints. The trail shoulder MUST be in external rotation and the trail hip level with the lead one, not higher.
THAT’S ALL. You can, through trial and error, find positions that allow these two joints to be placed correctly, OR use the Minimalist Golf Swing, which positions ALL joints at the TOP of the DOWNSWING. Why do more?