YODA,
This is indeed the best right forefinger drill I have ever tried. This is very different than keeping the right finger down the side of the shaft, which does not compare to this.
With your drill, on the chipping and short pitching green, all I keep hearing is "click" after "click" of the clubace hitting the ball.
Yay! Isn't it great?
When I go back to my 'regular' Grip, I never hit the first few as solid as I was hitting them with the Finger Grip. Nor do I feel nearly the control of my Hands, especially in those delicate little shots that require a slow, constant Hand speed. This one is a real 'keeper!'
As for when this evolved, I can tell you I have never seen anyone discuss using it for full motion shots, only putts.
EdZ,
I'm not trying to beat a dead horse here, but as a point of interest...
Peggy Kirk Bell, the famed LPGA Professional and owner of Pine Needles Lodge and Golf Club, attended our Workshop. Each year many hundreds of women attend her hugely popular clinics known as The Golfari. She was on the front row as I began introducing the 'Forefinger' idea, and she piped right up and said that using an extended forefinger down the shaft was one of her standard techniques.