Golfers frequently ask what is your longest driver? This statement assumes that some manufacturers are able to make drivers hotter than others. The truth of the matter is that in the past 5+ years almost all drivers have pushed the USGA/R&A limit on COR/CT value to the max. So the law of physics would mandate that all drivers now go the same distance, right? Not necessarily true as there are other factors that play into achieving distance, but they all have to do with custom fitting.
The professional fitter will generally first select a club head model that maximizes ball speed to swing speed for a specific golfer, which is called Smash Factor or Power Transfer Index A good fitter can generally achieve a ball speed that is 1.5 times faster than the club head speed. Next, the fitter analyzes the dispersion rate, while sustaining a high ball speed. After that, finding the perfect launch angle to best match ball speed will assure optimal trajectory. Lastly, the fitter creates the ideal spin rate. Only when the fitter has matched all four of these factors do we have the longest driver. Ball speed and contact are the most critical, followed by launch angle and spin rate.
The fitter will check the golfer’s average ball speed with a launch monitor. Impact tape and a launch monitor are both used to asses the ability of the player to hit the center of the face where the greatest rebound (highest COR/CT) are located. Lastly, counter balancing the club generally will improve the average contact.
A good fitter always takes into consideration the player’s preferences and what appeals to their eye. The following are some fundamental rules that should be considered:
(a) the smaller the head, the easier it is to create workability
(b) the larger the head the straighter the ball will fly
(c) the higher the MOI, the harder the club will be to square up for initial contact (yet ball flight will tend to straighten)
(d) the lower and deeper the COG (center of gravity), the lower the spin rate.
Matching the right shaft to the correct head is crucial in the fitting process. The playing properties of shafts will affect each club head differently for both spin and launch. All shafts are not created equal as quality control can vary with some manufacturers. Have your fitter check the shafts in your bag and you may be amazed on how off they can be in a set of irons. Every manufacturer also measures flex, torque and balance by different means, so the fitter has to be fairly well versed in the properties of every shaft and every brand.