So, today I ventured on to the practice putting green with the string line GM kindly gave us many moons ago. I placed the peg into the grass centrally behind the cup and the other end on a straight putt but slightly up hill
I took my normal putting position which isn't right over the ball, (and I've seen plenty of Utube videos extolling that position) I rolled several 4 foot putts in perfectly well . I then set up the same and the ball was exactly bisected by the stringline according to my set up and I decided to look along the line from behind and, low and behold, the stringline was actually over the left side of the ball - now it's clear that from my normal setup I was looking at the line from a different angle and it just "appeared" to all be in line. I then looked directly over the ball with the stringline actually over the centre of the ball with a slight grip change (lower down the grip) the ball rolling better and I never missed.
So, finally, my question, what effect, if any, does not being right over the ball have on alignment and subsequent stroke particularly over a longer distance?