[neil]

Assuming Dual Horizontal Hinging (10-10-D) or even Dual Vertical Hinging (10-10-E) or simply Angled Hinging (10-10-C), I agree wholeheartedly with Neil. The 'Dual' refers to one Plane of Motion for the Clubshaft (Inclined) and another for the Clubface (Horizontal or Vertical). In other words, whatever the Motion of the Clubface -- Close Only (Horizontal Hinging), Layback Only (Vertical Hinging) or Simultaneous Close and Layback (Anged Hinging) -- we assume an Inclined Plane of Motion of the Clubshaft, i.e., the Golf Stroke itself.

However, with a Putt or very short Chip Shot, the Clubhead can be made to cover the Line, thereby remaining in a Vertical Plane and thus ignoring the Inclined Plane. Then and only then will the Club continuously 'scrape the wall.'

Normally, though, the Club is swung on an Inclined Plane. Then, with the Ball located somewhat back of the normal Low Point, i.e., opposite the Left Shoulder, the Clubhead will 'scrape' very little a vertical wall in Start Up. Instead, it will move Up, Back and In immediately on an inclined wall. In so doing, it will always point at -- but not cover! -- its Straight Line Base Line (Plane Line).

Then, having merely scraped the wallboard momentarily in Start Up, the Clubhead will obliterate it as it moves Down, Out and Forward through Impact and Low Point during the Follow-Through.

My answer -- an answer.

Yodas' answer - THE WORKS.