Fitting yourself for Lie Angle with your putter.....

[Yoda]

:

The forearms should be inline with the puttershaft. It is the same thing as going to impact fix with the right forearm in plane with the shaft (12-3-0) Section 2 Number 6. With putting the shaft will have better support with the putter and rear forearm in plane with the putter.

The reason for the left forearm in plane is a matter of sameness and a matter of alignment.

Gripping the Putter in the lifeline of the Left Hand -- not under the heel -- zeroes out the #3 Accumulator (Left Arm and Clubshaft Angle). Combined with a Level Left Wrist, this automatically creates a theoretical Left Shoulder Plane and an On Plane Left Forearm. This is the basis for the Pick Minor Basic Stroke (10-3-G) -- Elbows Bent and both Forearms On Plane -- described by Homer Kelley in prior editions of TGM as "Yip-free."