Allow me to address what Ursus refers to as the spyglass effect. He is referring to how the yellow marker effects putting power. Here is an explanation:
The Yellow Marker
The yellow marker CAN effect the putt, but it doesn't always.
Here is what the yellow marker does:
Wherever you set the yellow marker, lets say at 45 feet, it tells the game that this is your intended distance. Now, lets imagine the backswing goes from 0 (putter not moving) all the way back to 100 (the putter at its furthest back). And let's say, for the purposes of this demonstration, that your putter's max distance on a flat, medium speed green is 90 feet. So to achieve 45 feet, you would need to pull the putter back to 50 in that 0-100 scale, right? Well, the yellow marker has told the computer that 50 is your intended power and it smooths the edges around that 50 mark by 1 or 2 on each side. So if you pull back to 48-52, you will get the same results.
This is done to account for the lack of pixel-perfect fidelity in the controls. That is how it can effect a putt.
Now, if you had the exact same scenario - you put the marker at 45 feet, but you only had a 9 foot putt, it would not effect the putt at all. This is because, using the previous set up, you would be pulling back to 10 in the 0-100 scale (10% of 90 = 9) and the smoothing effect of the marker distance would have no effect (because set at 45 feet, it would only effect putts around 50%).
The way the game is intended to be played is that you set the marker at the distance for which you want to aim, which should be about 2 feet past the hole on flat putts, and then adjusted from there for elevation as described in my above posts. You will have to adjust for slow to fast greens, of course, which can be done by either changing your aim or by using less or more backswing.
All that being said, there are people who play perfectly well, and enjoy it, by moving the marker 100 feet out every time (marker doesn't effect the power at all) and also those who don't adjust the marker at all, they just leave it hole high. They have just learned to swing with slightly different parameters. There is no one way to do it.
Does all that make sense?