The length of the putter determines your primary setup and the ability to consistently contact the sweet spot of the putter. The length has an equal effect on both distance and directional control. The skill required to consistently hit the sweet spot which is the center of gravity in the putter is a big determination in distance control. The higher the skill level the tighter the pattern for center hits. An example is the tour player will consistently hit the center within a 1/4 inch of the center whereas an 18 and over handicapper will hit within a 3/4 to 1 1//2 inch of center. Off center hit putts are not solid and do not travel the expected distance. I have at times tried to purposely hit the putt on the toe when putting a slick downhill putt so it won't travel as far as normal.
The shorter the putt the easier it is to hit in the sweet spot and the longer the putt the bigger range of mishits both vertically and horizontally. So to consistently hit the sweet spot the proper length putter accurately fitted will help the consistent contact. The best kind of putting stroke is that of a pendulum stroke where the golfer is bent over slightly at the waist and the eyes are directly over the ball or slightly to the inside. The shoulders feet and hips are square to the putting line. It is by far the most effective setup as most all the best players in the world use some type of pendulum stroke. One of my favorite swing aides is the Eyeline mirror that will let a golfer see his eye, shoulder and face alignment
THE CHECKLIST FOR GENERAL SET-UP
Feet Shoulder Width Apart Or Slightly Narrower
Knees Slightly Flexed
Spine Angle Tilted Until The Golfer's Eye's are over the ball
Arms Hanging Directly Under the Shoulders
Shoulders, Feet, Knees and Hips, Square to the target line
Ball Positioned Off Left Heel or Just Forward of the Bottom of The Putter's Arc
The average length putter for women is 30" to 33"
The average length putter for men is 32" to 35"
Most manufactures have the putters too long for the average player and this is why it is important to properly fit the putter length to the individual. Keep in mind that the proper setup determines the correct putter length and many times a putting lesson is necessary to maximize the potential of the golfer during a putting fitting.
Remember the Five P's for Improvement.
1) Professional Instruction
2) Properly Fit, Quality Equipment
5) Positive Attitude