I've recently added a factor into my putt reading which has increased my accuracy in certain circumstances. Just thought I would share it. Hope it helps.
The scenario is a putt with a severe break in relation to the elevation. As always, green speed should be taken into account.
Let's say you have a 12' putt with a severe right to left break and the hole is uphill 2". Logic states that you should aim right and hit the putt the equivalent of a 14'er-ish.
If you use your target to trace the projected path of the ball, you will see when and where the break happens much more accurately than just looking at the grid.
Sometimes you have to go uphill 4" or 5" and then come downhill 2" or 3" after the break. This putt will usually end long and right of the hole, because the first half of your putt doesn't have enough power to get it high enough and last half of your putt is actually a downhill 6 footer even though it's 2" above where you started.
Sometimes the putt is a constant 1" or 2" above along the whole path to the hole, in which case your speed will be correct.
Sometimes the putt will be level at the beginning and rise sharply halfway there. In that scenario, the putt will weaken and die high and short of the hole, because the ball was traveling too fast at the beginning to be affected by the break and didn't have enough power to get back up the hill once it slowed down.
Knowing the elevation of the hole in relation to your starting point is a great benefit, but it's only half of the story. Knowing the elevation along the whole path to the hole will result in more made putts and tap-in pars.
My next area of focus will be on how (or if) wind affects putts...