Quoted from Tom Wishon January 2013 E-Tech Report...
Are Too Many Golfers Becoming Obsessed with Driver Spin Rate?
A discussion of the Relationship of Clubfitting to Driver Spin Rate
One of the areas of fitting analysis that seems to have developed momentum in the past several years is how many golfers see their backspin measurement on a launch monitor and, a) obsess that their driver spin rate is not in the low 2000 rpms, and b) believe that they can achieve a lower driver spin by changing to a shaft that can enable them to get their spin number lower – without ever taking the time to determine if they do in fact have a spin problem and if so, then trying to find out what best can reduce their spin to achieve a better ball flight.
Here are some facts about Driver backspin learned over many hours of research in clubhead design, shaft design and Clubfitting research:
Spin outputs from some launch monitors can be inaccurate and inconsistent.
Accurate backspin measurement of a golf shot is a highly complex operation. The output for spin is in revolutions per MINUTE. Yet a launch monitor has only a fraction of a second in which to measure how much the ball is spinning upon leaving the clubface. This means with every launch monitor, a math calculation has to be incorporated with the amount of spin “seen” in a fraction of a second to come up with the RPM measurement.
During the time a camera based launch monitor actually “sees” the ball spin, the ball does not even complete one full revolution. Therefore, the spin recognition of the launch monitor has to very accurately measure exactly how much the ball actually rotated during the time it was being “seen”. If the device misses the amount of revolution by say, 10 degrees out of a full 360 degree rotation, by the time the math calculation is done to output an RPM measurement, the final spin measurement can be way off.
TrackMan and Flight Scope use phase array, pulsing Doppler Radar to measure spin. Both units shoot the radar beam at the ball from behind the shot and thus are able to pick up data from the ball’s movement for several feet after impact. This is in comparison to a camera based system which only sees the ball over a couple of inches after takeoff and explains why the TrackMan and Flight Scope launch monitors are more accurate in their spin measurement.
Please understand that when we talk about launch monitor inaccuracy, we are ONLY talking about spin measurement. Most all of the other launch monitors are accurate enough for clubhead speed, ball speed and launch angle to allow accurate fitting decisions to be made for specs which relate to these other parameters.
Most golfers hit Range Balls on a Launch Monitor, not “Real Balls”
The majority of launch monitor sessions are conducted with range balls. Most range balls are one piece golf balls which rarely have similar spin characteristics to the premium balls that golfers typically use when they play. Not only that, but range balls suffer wear from getting hit a lot more times than will a premium ball. Add it all up and it is difficult to very difficult to try to make valid conclusions about spin measurements when hitting worn range balls on launch monitors that may not have the ability to accurately measure backspin.
There most definitely is a difference in spin between different models of premium golf balls. To get the most accurate and valid spin measurement for each golfer’s game, it only makes sense to use the ball you typically play and do it with either a TrackMan or Flight Scope launch monitor.
The best way to determine if you have a spin problem is to observe the flight of the ball, not by reading the spin output from a launch monitor.
Just because a tour player’s driver spin is in the low 2000 RPMS does not mean that is the optimum spin for all golfers. The optimum amount of spin for each golfer differs depending on their clubhead speed and angle of attack. The slower the clubhead speed, the more spin is needed to generate enough lift under the ball to help keep it in the air to carry farther. And vice versa, the higher the clubhead speed and ball speed, the less spin is needed to generate enough lift under the ball to help keep it in the air to carry farther.
In addition, the more downward the Angle of Attack, the higher the loft has to be to allow the golfer to achieve his optimum launch angle, which in turn is going to automatically increase spin. And the more upward, the A of A, the lower the loft will be to optimize the launch angle, which means lower spin will come with that.
Following are data charts from TrackMan which show their findings for what are the optimum driver launch parameters are for different combinations of clubhead speed and angle of attack. From TrackMan’s research it is easy to see that spin has to increase as clubhead speed slows and the angle of attack is more downward. Charts are offered for optimum CARRY distance as well as for optimum TOTAL DISTANCE as per the conditions of the fairways and their conduciveness to more or less roll of the ball after landing.
The use of these charts is simple – for each golfer, find whatever driver loft results in a launch angle, ball speed and spin rate that is close to the chart data for the golfer’s clubhead speed and angle of attack. The charts show the optimum driver launch parameters for both maximizing Carry distance or Total distance (Carry + Roll). Use Carry distance optimized parameters when fairways are wet or not conducive to roll after landing. Use Total distance chart parameters when fairways are firm and conductive to more roll after landing.
Whether a golfer has too much backspin for his clubhead speed and angle of attack depends on the ball flight shape as the ball flies through the air.
Higher ball speed golfers need to learn how to visually identify what a shot hit with too much spin looks like rather than to make conclusions based only on a launch monitor measurement.
For shots hit with too much spin, the ball typically curves rapidly upward to a higher apex in flight, after which the ball seems to hang for a little moment at the peak of its apex and then fall more steeply to the ground. From a side view, an exaggerated graphic of the flight shape of the excessive spin shot looks somewhat like the following graphic:
A more preferred driver ball flight shape would look more like this:
There is nothing wrong with hitting the driver high, as long as the angle of descent of the ball to the ground is less than 40*. For example, a ball flight shape such as the below image which still flies very high in the air is fine, but of course it is preferable for the descent of the ball upon landing to be no higher than 40 degrees:
Bottom Line: Learn to watch the flight of the ball and make conclusions about spin results from what you see before you make conclusions from what the launch monitor outputs for a spin number.
The vast majority of excessive spin situations are caused by swing errors far more than from playing the wrong equipment – and are more often cured by changes in swing technique than from changes in equipment.
What causes the excessive spin shot? From our research and fitting observations, the two most predominant swing errors that result in excessive spin are:
- A downward angle of attack into the ball with the driver which requires the golfer to use more loft to achieve their optimum launch angle, which in turn increases spin.
- A breakdown of the wrist of the upper hand on the grip coming into impact which allows the clubhead to pass in front of the hands before impact, thus greatly increasing the dynamic loft of the clubhead and increasing spin and launch angle along with it.