In selecting an "ideal" the putting stroke from the various options available, it is useful to have some criteria on which to base the selection. Here are some ideas:
The fewer the muscle groups involved, the simpler the stroke and the greater the consistency.
With only a few muscle groups involved, it is possible for the player to think in terms of contracting the relevant muscles at the relevant time.
Putting strokes can be divided between "basic" strokes that use only those muscles needed to propel the ball forward, and "hybrid" strokes that use some combination of the basic strokes. In this Guide, we focus on the "basic" strokes, and suggest all things being equal (particularly practice time), "basic" strokes will be better than "hybrid" strokes, because they are simpler and more likely to be consistent. With a simple stroke, the player can think about contracting one or two muscles and the ball will be propelled in the proper direction.
When more than one muscle group is involved, consistency drives the need to coordinate the work of the muscle groups. Because the putting stroke is symmetrical in the sense that muscle groups on both sides of the body typically operate to execute the backstroke and forward stroke, the need to coordinate muscle activity is almost always unavoidable. It is desirable that these muscle groups not work independently, but work in a coordinated way. This will produce intrinsic consistency in the stroke, and reduce the need for continual practice to get the consistency. An example of muscle groups acting independently is when the stroke involves moving the right and left shoulder blades. These blades can move independently. One blade can move up, the other back and down, etc. An example of muscle groups acting in a coordinated way is when the stroke involves rotating around the spinal column. The muscles on both sides of the body are forced to work in a coordinated way because of the spinal column. In fact, the brain has learned to instruct these muscles to operate in coordination, so the coordination occurs without conscious thought.
Some joints in the body allow movement in a wide variety of directions. Examples include the wrist and ankle joints, which allow the movement move up and down, forward and backward, and directions in between. Examples also include the shoulder and hip joints - ball and socket joints which allow the upper arm and upper leg respectively to move in a variety of directions. The brain is so accustomed to moving these ball and socket joints within their full range of motion that getting consistent movement along one path is not automatic. Other joints allow restricted movement. Examples include the elbow and the knee, where movement is allowed in one plane with minimal twisting. Unfortunately, the knee and elbow are not active parts of the putting stroke. The spinal joints lie somewhere between the unrestricted movement of the wrist, ankle, shoulder and hip joints, and the restricted movement of the knee and elbow joints. While the spine can bend forward and to a limited extent backward, to the left and right, and can twist left and right, the muscle groups that cause these movements are not close together, so it is much easier to isolate the use of muscles and restrict movement along one path. All these being equal, joint restrictions should help achieve putting consistency.
The conventional wisdom is that the use of bigger muscles over smaller muscles is more likely to be effective in minimizing the likelihood of the yips in pressure situations. This argument was used to justify the movement away from putting with the wrists. One counter argument is that muscles that are commonly used for precise movement (e.g. wrists and hands) might be better suited to the precision needed in putting.
Regarding the yips and putting under pressure, an additional factor that may have some relevance is the mass being moved. When moving a large mass, effort is needed to get the mass moving, but once in motion, momentum takes over and the mass moves in the direction set for it. In putting, there is less momentum in a wrist stroke that moves only the putter, and more in a spinal twist stroke that moves not only the putter, but the wrists, the upper arms, and the shoulder sockets.
It is useful to keep the eye sockets still on the back and forward strokes. Still eyes are useful in monitoring the stroke in progress, controlling the length of the back stroke, monitoring rhythm, and making subtle in-stroke corrections. Note that still eye sockets require a still head. A still head would normally, but not always, entail a still spinal column, particularly at its top. While it is conceptually possible to have a still head without a still body, a lot of muscular activity is needed to generate a still head. This activity requires the involvement of additional muscle groups and complicates the stroke.
The importance of the eyes in the putting stroke is illustrated by the fact that very few players putt with their eyes shut.
In theory, an intrinsically sound stroke should be effective without using the eyes.
Like the full golf swing, the putting stroke relies on rotation. The putter head is tracing out a path around the perimeter of a circle.
The circular nature of the putting stroke is often under appreciated. One reason is that the putting stroke covers only a small portion of the perimeter of the circle. If one uses a wrist stroke and a 32 inch putter, a putting stroke that involves a 12 inch backstroke and 12 inch follow-through represents only 11.94 per cent of the circle circumference. Despite the fact that the putting stroke covers only a small part of the circle circumference, it is important to realize that the throughout the stroke, the putter clubface is moving around the circumference of a circle.
The most obvious manifestation of the circular path of the putter head is the rising of the putter head off the ground on the backstroke, its return to a low point around impact, and the rising of the putter head on the follow-through.
When we perceive the putting stroke as a rotation, then several questions arise. What is the rotation plane relative to the vertical? Where is the centre of the rotation? What is the radius of the rotation circle?
A stroke that sees a properly aligned putter head go back along the line of the intended path and forward along the line of the intended path will always put the ball on the intended line. Getting the club head on this path requires that the plane of the rotation should be vertical to the ground and in the direction of the target. With this type of rotation, regardless of the low point in the circle traced by the putter head, the ball will set off on target (assuming the putter face is aligned correctly).
Dave Pelz, in his Putting Bible, argued convincingly about the merits of a vertical rotation plane (although he did not characterize it this way)
Variants from the ideal rotation include vertical rotation aligned to the left or right of the target; non vertical rotation; and combinations of the foregoing. With non-vertical rotation, the putter head is moving around the circumference of a circle relative to the target line. There is only one impact point in the rotation that will set the ball on target. Other impact points will set the ball to either the left or the right of the target. In the diagram, the solid red line illustrates the top view of a non-vertical rotation where the impact point sets the ball along the intended target direction. The dotted blue line illustrates the top view where the impact point sets the ball to the right of the target direction.
The bigger the radius of the circle around which the putter is travelling, the less significant are the direction problems related to a non-vertical rotation plane. With a putting stroke using wrists only, the radius of the rotation circle is the length of the putter. Putters tend to be in the 32 to 34 inch range. With the putting stroke using other options, the rotation radius is approximately the distance from the shoulder to the ball. This distance depends on the player's height from ground to shoulder, the amount the player leans forward, and where the body is placed relative to the ball. This distance could be in the 48 to 52 inch range. The problem with the lower circle radius is that for a 12 inch backstroke and follow-through, one is going much further around the circle and therefore more exposed to the curve in the circle.
With rotation, it is important to know where the rotation centre is. For example, is the rotation centre the wrists, the lead shoulder socket, the mid- point between shoulder sockets, etc?
With rotation, particularly non-vertical rotation, if the centre of rotation is moving during the putting stroke, the likelihood of starting the ball toward the target diminishes as there is only one point on the rotation circle that works, and movement makes it more difficult to find that point on a consistent basis. Vertical rotation is more tolerant of movement, since movement directly away from or toward the target still puts the ball on target.
Conventional golf teaching holds that the eyes should be directly above the ball at set up, or at least directly over the target line, and not to the left or right of the ball when seen from behind. The conventional argument is that with the eyes directly over the ball, or at least on the target line, by rotating one's head toward the ball, the eyes will track out the correct line.
This argument makes sense when the spinal column is horizontal to the ground and perpendicular to the target. Turning one's head will move the eye sockets directly down the path to the target.
When the spine is not horizontal to the ground (and it rarely would be) or perpendicular to the target, the rotation occurs in the neck and is perpendicular to the spinal column. Rotating one's head would move the eye sockets to the left of the target for a right hand player and right for a left hand player.
Note that the eyes move independently of the head position. In addition, they can move in a multitude of directions. Regardless of what one does with one's head and neck, eyes movements are critical to getting a good line. One can have an online head rotation horizontal to the ground sabotaged by eye movements, and an off line head rotation corrected by eye movements.
In other words, getting one's eye sockets on or over the target line is not critical to getting a good line.
However, there is much to be said for setting up on a consistent basis. A consistent setup will teach the brain to make the necessary adjustments that relate target to the alignment. Getting the left or right eye or the mid-position between the left and right eyes over the ball can form the basis for a consistent, repeatable body position.
There are limits how far the various joints can move. This puts limits on the length of the putting stroke, and how far one can hit the ball with a particular stroke. For particularly long putts, it is desirable to have a stroke that can get the ball to the hole, without resorting to another type of golf shot.
No one putts with the spine vertical. Every one leans forward to some extent. The execution of some putting stroke options improves considerably with more forward lean. This performance related incentive to lean forward can lead to back problems. Forward leaning can put stress on the player's back, particularly if the player is inclined to practice putting for long hours. At the end of the day, posture needs to be taken into account when considering putting stroke.