Why do golfers hold there putter horizontal when trying to putt?

Question

Why do golfers hold there putter horizontal when trying to putt?

Answer 1

Consider this, when putting. the ball is placed in your stance straight down from your left eye.  The putter is going to make contact, with a proper arms and shoulder swing, with a slightly upward motion in order to start the ball rolling smoothly.  So, they tilt the putter slightly forward of vertical to ensure proper contact with the ball.

Answer 2

what you learn is what you get

Answer 3

I think you meant to ask why they hold it "vertical" when reading a putt before they strike it.  They are doing what is called "plumb bobbing", and it is a way to measure how much break is in a putt and how far to one side or the other of the cup to aim the putt.

Answer 4

A player may hold a putter horizontal across his knees as an aid to indicate the proper line. He may also lay the putter on the green to align his stance for the same reason. No club or any other outside element may be used during the putting stroke for alignment purposes.