Many great responses here - I appreciate everyone's thoughts.
Yes, of course, Kevin and DC are correct that this was a quote from Jacobs.
I thought it was interesting and posted it for a few reasons.
One is that, as DC said, JJ had a few drills or exercises, or "band-aids" for an in-to-out path. But as far as I can see, he linked that path with pushes and hooks. I didn't actually include this in the quote [and probably should have, sorry!], but the definitive ballflight "symptom" for this treatment was starting right, and curving further right. But with occasional snappers thrown in.
It would seem that he reckoned that push-fades were a sure sign of "rocking and blocking" as he called it.
I also thought it was interesting because of the emphasis on posture. I remember when posture, and "stand tall to the ball", was what everyone seemed to talk about. Now it seems, not so much.
So I thought it was notable, or as Oliver and Wulsy put it, "simplistic"
![Wink ;) ;)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
to see a direct link drawn between posture and ball-flight. Although, I'm not sure that anyone sounds terribly convinced by this...
Now, if anything, the wheel seems to have turned full circle and some people are prescribing steeper shoulder turns and more bent over postures, even "slumpy shoulders". And I'm sure Brian has recounted Ben Doyle teaching him to "bend over like a proper golfer" - though I'm not sure I necessarily understand why.
Lastly, Kevin and DC talked about taking out the "under" as well as the "in-to-out". For the sake of argument, if you're standing more erect, don't you need more armswing just to get the club back onto the ball, and might that not make impact less shallow? Just my tuppenceworth.