If the area of rotation is not directly over the ball and/or the spine is not horizontal and/or the shaft is not vertical to the ground the putter head cannot work straight back and through without skillful compensation and manipulation by the player. The natural laws of this universe prevent it.

When the area of rotation is vertical to the ground (a.k.a. swinging door) the putter head will travel in a complete circle. Until a one inch golfer comes out of the wood work we will not see this set up. When the area of rotation is angled to the ground the putter head will move in an arc along the ground.

Hold your horses! Everything in the previous two paragraphs is dependent on the shoulders controlling and powering the stroke. A person who uses only his/her wrist (nothing else on the body moves) does not care how he sets up with the upper body, because it is of no use - with exception of the eyes for aim. A person who uses an arm-only putting stroke (one where the right arm is used to power or move the putter) must be aware of his set up because the when the arms are activated for the putting stroke the shoulders rotate.

It is just as Mr. Kelley said, “Movement of the shoulders does not violate a zero pivot.”

So just as with building a house, the further you go the more options appear, and you must make a decision on what you want.

The best putting stroke has two things, a square face at impact and pace for the selected distance control. The majority of great putters of the modern era set up with their eyes over or slightly inside the ball/target line, the forearms level, the forearms in line with the putter shaft, and their upper spine held at an angle. For the same reason there is no perfect golf swing model, there is no perfect putting stroke model. However, the laws of force and motion, putter design, alignment, and human anatomy do push pretty hard for most humans to set up in certain ways.

ROUND FIVE

“I am not disappointed when I miss a putt, I’m disappointed when I miss-hit a putt.”
All Great Putters

The truth of the matter is that we will make more putts if we hit solidly than if we miss-hit. Most amateurs, and professionals for that matter, would lower their putting average by not trying so hard to make the putt go in the hole but by focusing on hitting the putt solidly. The truth of the matter is if the upper spine is not horizontal to the ground or the area of rotation is not directly over the ball, it will take skillful manipulation to create a putting stroke which is straight back and through. The truth of the matter is the more manipulation the greater the chance for miss-hits. The truth of the matter is the shaft moves straight back but the putter head moves in an arc. The truth of the matter is that most players (95%) do not putt with their spine horizontal to the ground or the area of rotation directly over the ball. The truth of the matter is that 95% of golfers want to shoot lower scores and know that the putter makes the difference. The truth of the matter is that a laser attached to a shaft will move straight back and through, and the putter will move in an arc. The truth of the matter is this debate will go on, just like politics, because people want to be correct and will bend definitions to do so. The truth of the matter is that the putter head moves in an arc while the putter shaft moves straight back and through, and that is not just my opinion.

For all of you who agree, great! For all of you who disagree, great! That is the wonderful thing about sports – as you absorb and apply, you make it your own. Mastery is at our fingertips, and it doesn't cost a thing.