To roll the ball down the target line with an end over end roll, the putter must strike the ball in a square position. Square is when the putter face is exactly at right angles to the target line. To have the face square at impact you must have the face square at address to avoid manipulation.
When the face is not square
I will go through an example and prove to you the importance of addressing each and every putt with the face square.
Example
When the face is open (aimed to the right of the target line at address)
When the face aims to the right
Assuming that everything else aims parallel to the target line and that you make a good stroke, this open face address position will result in a putt that is slightly pushed. (A push means that the ball comes out right of your target.) From this situation the following will result. You start missing putts to the right. To compensate you either aim more left with your body or you develop a pull in your putting stroke. Your stroke becomes full of manipulations and you start down the road to disaster.
