Piece
Tour Winner
I agree. It looks to me like what would help you is practising >4ft putts. I have improved since I had a lesson on this distance. My backswing was too long and I was deaccelerating through impact. The drill the pro gave me was to place a tee peg 4-6 inches behind my putter and make a backswing without touching the tee peg. This gave me the feeling of speeding up through impact although I probably was not. If I have only a few minutes on the putting green prior to going out this is what I practise. Once I have nailed 3 x 3 footers I increase it to 4...then 5...etc...
Only my opinion. Please dont shoot me ;-)
Interestingly, my pro says different to your pro! The short backswing, accelerating through to a longer follow through, does stop deceleration but does mean that you hit the ball rather than stroke it. The top players definitely stroke it with only a slight difference in length between backswing and through. I used to do the former and thought i was a good putter - now I've been taught the latter, my putting is much better as most putts look like they have a chance with consistent length.
I guess it's down to personal technique... Just my opinion