Something to consider if you struggle with putting mechanics. Does your body respond to your hands? Or. Do your hands respond to your body? Confusion pertaining to this matter can create some serious problems.
Just curious, but what do you do if, in the act of making a putt, you think that the back of your left hand isn't on the line of your putt?When I putt well my hands are passive following the movements of my shoulders. I try to maintain the triangle of my shoulders to my hands. Therefore my hands respond to my body (or in this case shoulders). I try to make sure I have a very solid foundation so that there is no sway of the hips or movement of my legs. I also imagine the back of my left hand making contact with the ball on the line of my putt. Does that make sense?
FYI Tiger Woods, Brad Faxon, Loren Roberts, and Ben Crenshaw are the first of many who come to mind that have backswings longer than their follow through.I've observed that most consistently good putters (and chippers) have a relatively short backstroke.
When the backstroke is long there may be a tendency to decelerate the downswing, and that causes ball control problems.
I think for many players a relatively short putting backswing promotes a nice downswing acceleration , which improves contact and control of the ball.