My guess would be that once you've done the Hula-Hula, a steady acceleration Clubshaft lenghthwise helps maintaining lag however one would have to be able to properly release the lag and overacceleration would cause loss of Lag Pressure.
This is in contrast to Drive Loading where the Start Down is a slow and deliberate transport of the power package to the release point in order not to run out of right arm before follow-through.
I understand proper sequencing and the downswing starting "from the ground up" per Hogan, or Hula-Hula. But regardless of swinging with the "steady acceleration Clubshaft lengthwise" or hitting with a "slow and deliberate transport of the power package", the Start Down still does not feel like a "quick" movement to me. I think I am missing something important as I am fairly confident that Mr. Kelley did not italicize those terms without good reason.
I'm foggy on this quick vs slow thing too, great question. It feels slow either way to me too.
I'd guess that the distinction is between Drive and Drag Loading and the existence of any Hip Work as opposed to merely Hip Motion. Any Hip Action, Work tending to induce Pulling and therefore Longitudinal Acceleration as opposed to Drive Loadings purely Radial Acceleration.
Ground Up vs not Ground Up in other words. Were talking 12-1 pure Drive Loading not just any old form of Hitting here. A hitter using a Swingers Startdown would be Ground Up and pull hard, longitudinal acceleration prior to Thrusting Radially.
Here is a response I received from Yoda many, many moons ago, when asking the same question:
"When Power is a consideration, Swingers must generate an Instantaneous Acceleration in the Start Down to 'Crank the Gyroscope' and 'spin the flywheel' (2-K). This sets up the Centrifugal Downstroke Release Sequence (6-M-1). For Hitters, that Acceleration must begin slowly and then be Timed for Maximum Thrust through Impact (6-C-2-D and 6-F-1).
The idea is that an instantaneous Hip Action -- this is the 'quick' -- initiates the proper Downstroke On Plane Right Shoulder Turn and Release Sequence. When Homer talked of this Swinger's Start-Down, he would always refer to "Hogan's move."
Nevertheless, even though the Acceleration generated by the Hip Action is 'instantaneous,' the Hands still Feel the Loading as 'deliberate, positive and heavy.' In fact, the more 'instantaneous' the Hip Action, the more the 'held back' Hands Feel 'deliberate, positive and heavy.' Even though this loading action will cause the Hands ultimately to move faster in the Downstroke, they will not Feel faster -- only more...you guessed it:
Deliberate;
Positive; and...
Heavy.
It is an enhanced sense of Effective Mass versus Velocity (2-M-1)."
You can really feel the quick start down by using a preturned hip, at the start down, with the hip slide goes first, the shoulder the hands will response and all come quickly.
Drive Loaders and Drag Loaders , in Total Motion, can Slide their Hips (with a Delayed Hip Turn) to Tilt the Axis and lower their Right Shoulder. (Edit: I believe the 7th edition changed 12-1-0, 12-2-0 pt 14 Hip Turn from Standard to Slide)
The question, I think, assuming I have Homer's definitions straight , is the nature of the Hip Turn.......is it Work or Motion? Does it Pull hard to set up a Swingers Centrifugal Throwout Action or merely support Muscular Driveout for the true Drive Loader. Longitudinal or Radial? Does Hip Action pull the Right Shoulder Down and Through the shot or does Hip Motion merely aid in the sneaking of the Right Shoulder down to the Release Point , a position from which the Right Shoulder can then backstop the Driving Right Arm Throw.
But their is a hybrid .......you can also Spin the Flywheel and then over ride the Swingers CF Throwout Action with an Active Thrust of the Right Arm (Right Arm Throw with Pitch elbow not Push for Total Motion). This'd be your 4B Hitting Procedure, I believe.
There's a difference in the location of the Lag Pressure Point for all of this stuff. Rotated vs non Rotated Lag Pressure Point #3, see 6-H-0 . Its critically important to understand how these procedures should feel in the Hands so that you can properly monitor them via Lag Pressure.
I remember a great photo sequence in Jimmy Ballard's How to Perfect Your Golf Swing. It was of Tom Watson, 2 photos, one right at the top of the back swing, the second after the beginning of his hip turn on the downswing. The club looks like it is in the exact same position, except it is bent in the second photo. He has already created his lag with that hip move, and that happened very quickly.
I have more luck thinking of lag as shaft bend rather than body position or geometry. Once you bend the shaft coming down, you must keep it bent until after impact.
I remember a great photo sequence in Jimmy Ballard's How to Perfect Your Golf Swing. It was of Tom Watson, 2 photos, one right at the top of the back swing, the second after the beginning of his hip turn on the downswing. The club looks like it is in the exact same position, except it is bent in the second photo. He has already created his lag with that hip move, and that happened very quickly.
I have more luck thinking of lag as shaft bend rather than body position or geometry. Once you bend the shaft coming down, you must keep it bent until after impact.
Im not sure if you can really hold shaft bend but the thought or the attempt to do it is good to my mind. Interestingly Homer is on record as seeing what we call shaft kick or backward bending pre impact to be the shaft lagging the line or sweet spot plane between the #3pp and the clubhead. The text in the book seems to support holding shaft bend however .......something Im confused about. If he came to see shaft kick as lag why didnt he edit the book accordingly. Maybe I read it wrong.
I dunno. Im going from memory dont have my book with me.