Gary Player once pointed out 'one of the biggest faults' amateurs make when swinging a golf club

The golf swing: always practiced yet never perfected. Forever trying to improve. Which swing is your favorite? | Gary Player

Here’s a quick Monday Mantra to better your game this week: tell yourself “slow, then fast” the next time you tee off. I was once told that there is only one fast movement in the golf swing. At first that sounded like complete nonsense but when you think about it, it makes compete sense. Keep your backswing slow so that you allow yourself time to rotate through the ball as fast as possible. Make sure the fastest part of your swing is through the ball. Good rotation through the ball is essential

Gary Player - Wikipedia

Gary Player Biography: An International Icon Of The Game