FWIW, this method is alarmingly accurate. If you bother to take the time to use it I have no doubt 2 things will happen. 1-Any putt becomes a tap in if you don't sink it. 2-You will see what you need to see to eventually be able to putt by feel.
I found that once you get the hang of it, it becomes real easy to do the math quick. The hardest thing is rating the speeds of the dots at first but after you see enough of them that too will come easier. Then you find yourself adding the speeds up as you rate each line and then it's simply (distance X dot speed) / lines.
Fascinating, Gold, more so because it pretty much validates the way I've been doing it for a long time, just with numbers. :-)