Why Shallow the Club?

[Toggs]

I see a lot of videos on shallowing the club on the downswing. This may be a stupid question, but why not just swing back on the shallower path in the first place, then swing forward on that same path.

 

[razaar]

The golf swing is a turn, turn and wack it discipline in its simplest form. The clubhead is flailed on to a ball with a two lever swing around a central hub located in the upper sternum between the shoulders. The power in the swing comes from the body's larger muscles in the legs, pelvis and trunk. The shoulders and wrists are hinges of a two lever system attached to the central hub.
The backswing gives width to the swing via an extended target arm that is drawn back from the ball on an arc aimed at an extended ball/target line (the plane line). During the backswing the body and pelvis are coiled around the swing hub with the legs and spine being twisted against the ground.
The downswing is a reverse of the backswing with the body unwinding from the ground up via the body's centre of mass located in the middle of the middle of the pelvis. The pelvis turns towards the target with the body resisting to start the downswing which tightens the coil and drops the arms on an inside path under the target shoulder. It is this inside path with the trail elbow moving towards the target ahead of the hands that shallows the club. Once the hands pass the trail elbow the wrists will unhinge releasing the stored power of the backswing. It is important to keep the elbow ahead of the hands for as long as possible to give the swing power.

 

[Desmond]

I see a lot of videos on shallowing the club on the downswing. This may be a stupid question, but why not just swing back on the shallower path in the first place, then swing forward on that same path.

I can't tell you like the above ^^^ but taking it back shallower will get your arms too far behind your body and low for the downswing.