SamSpayed:Jay, upon further investigation, I removed the reference to the fmagnets video from my post. He actually doesn't use the vertical dots in his video. He does his analysis of offset putts in a slightly different way.
It would be very interesting to see if the putt would have gone in on faster greens. As we all know, Slow and Standard greens do straighten a putt up greatly. Also, remember the Putter precision tests thread from 2013 which showed that even if you hit the same putt every time you will not necessarily get the same results; the deviation is greater than the width of a hole. So, for the putt in the video, and taking into account it was Standard green speed, a ding'd putt could have still gone in even if there was a bit of break. I don't know if you can take mulligans once a ball has been holed, but if you can it would have been interesting to see how many putts out of 10 would have gone in.
In the video, the grid from behind the player isn't the same as the grid from behind the hole, so it's very difficult to ascertain what the correct line would be based on just those two views. I'm not saying Mag's analysis was wrong, but I feel it was more down to experience rather than just analysis of the limited amount of data, which is why people keep notes, either written down or logged somewhere in the brain.