Over the last 30 years, custom fitting for a set of irons has gone from being something quite niche to almost second nature, particularly following the advent of adjustable golf clubs.
There are many different approaches that usually involve launch monitors to provide exact data on how the club is performing when you swing and then specifications and adjustments are planned from there.
Usually shaft flex is determined by interpreting these results, but since 2009 Mizuno has been using their Swing DNA device to suggest the most appropriate shafts in as little as three swings. I went along to Mizuno's new National Fitting Centre at Gleneagles in Scotland to go through the Swing DNA process and find out more.
The Swing DNA device is a modified 6-iron with a sensor on the shaft that you swing and hit balls as you would with a normal club.
It doesn't feel out of the ordinary when you do this and the small LCD screen on the shaft shows a series of numbers after each of the three swings required, which my friendly Mizuno fitter called Roland tapped into his laptop.
The results are then shown on the screen with my average head speed of 82mph being used to determine the flex of the shaft. The other numbers created a ranking on a scale of 1 to 9 for Tempo, so my measurement of 4 meant a medium shaft weight.
The remaining 3 columns show how the club head behaved through the swing, ranking the Toe Down position, Kick Angle and Release Factor that all combine to determine the type of shaft.
It then plots your swing profile, or DNA, on a grid against several Mizuno staff players. Apparently I am closest to Luke Donald, which, apart from the same number of limbs and majors, is where any similarities between me and the multi-millionaire, former World No.1 end.
Roland then showed me the shaft optimiser screens that present the top three options for me to try out using Trackman to make a final choice.
The results were a little bit of a surprise as in some ways, as although the weights were around the same as my current True Temper Dynamic Gold SL, this shaft was not on the list.
Two of the options recommended a Soft Step or a Hard Step, which is when a flex is effectively cut in half. In a Soft Step you weaken the shaft flex by taking the shaft from a 4-iron and cutting it down to fit into the 5-iron and vice versa for a Hard Step.
The next screen suggests three different models to try out with these shafts and I decided on the Mizuno MP-25 as they have the most forgiveness in a Forged Boron Steel head that should give a little more ball speed than the other two models.
Using Mizuno's fitting cart they can interchange heads quickly using a wrench with the 6-iron head of any model in the range. The full set is then also there for you as well to try once the final choice has been made.
My money was secretly on the True Temper XP115 S300 shaft as I have used this in many recent iron tests where it is the stock shaft and I liked it. However you must never have pre-conceived ideas when you go into a fitting and it quickly became clear that the regular flex KBS Tour shaft with a Hard Step to make it stiffer was the best for me.
Not only did it feel the best with the MP-25 head, but as you can see from the blue circle below, it was also the most consistent for distance and dispersion, the two things that are the most important with irons.
With the club and shaft decided, we then had to fine tune the set up. Standing up straight with my hands by my side and taking a measurement from the middle knuckle of my hand to the floor showed that I needed an extra quarter inch on the shaft length.
Roland also measured the size of my hands and the recommedation was to build up the grips with four layers of tape under my preferred choice from the array of 22 grips on offer. Luke was not consulted on this.
Finally the lie of the clubs was calculated using a bit of tape on the sole of the club and then hitting shots off a Lie Board to see which part of the sole hit the ground during the swing. After a few shots it showed that I was hitting slightly towards the toe so the clubs would have the lie adjusted 1° up from standard to get this point back in the middle.
Once all the specifications were confirmed, it was then a case of deciding the makeup of the set, which iron you wanted to start at and what lofts you would like on your wedges to ensure that all distance gaps are covered.
The beauty of Mizuno's MP range is that all the different models come in the same lofts throughout, so it makes mixing and matching different models like this simple to ensure consistent distance gaps.
For instance you can replace the standard long irons with the more forgiving Mizuno MP-H5 long irons before starting the MP-25 set at 5-iron to PW.
To keep the forgiving theme going, I would go for the semi-cavity back S5 wedges which Luke Donald uses, so that is something else we now have in common, although I would draw the line at his Blue Satin finish.
And that was it. The results are recorded and emailed to the Mizuno Scotland Factory based at Cumbernauld in Central Scotland to be made. This not only serves the UK, but all of Europe, the Middle East and Africa.
Once the details are received by the factory then the clubs are usually dispatched within 2 working days. If you want to see how that is done then read the about my Mizuno custom fit factory tour.
The whole Mizuno fitting process was simple and done in around 30-45 minutes depending on how quickly you make up your mind. The Swing DNA club is a clever piece of kit and it is very impressive how quickly it produced recommendations for you to test out.
If you would like to experience this for yourself then there are currently 15 Mizuno Performance Centres in the UK & Ireland plus over 600 pro-shops and stores that have the Mizuno Swing DNA system, plus the same again across Europe. Details of where they are can be found on the Mizuno website.
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