Proportional Stringing: Can You Benefit?
Unknown to some, in his early days, Roger Federer is rumored to have had his racquets strung using what was called the “Starmaker” stringing pattern. While the details are largely unknown, the general consensus is that it was a variation of what we now refer to as proportional stringing.
The first question to arise concerning this pattern is, “what exactly is proportional stringing?” In short, it is a method of stringing that instead of using a single reference tension for the entire racquet, it attempts to tension the strings such that the relative stiffness (a measurement of force over distance) of each string remains the same. Looking at only the main strings, the way a racquet is shaped means that the middle mains are significantly longer than the outermost strings in most frames. If each section of string is pulled to the same tension, the shorter string will display a higher relative stiffness because the tension is distributed over a shorter section. For example, in order to achieve the same stiffness on a string that is twice as long as another, a force that is double that of the shorter string must be applied.
This is, of course, a bit of an exaggeration as the length difference between the longest and shortest string will typically be more on the order of a 35-40% change. The result is that in order to achieve a proportional string bed, one will change the tension of each pull based on the length of that specific section.
Again, the key is to not focus on the actual tension that is being applied to each string, but to concentrate on the stiffness characteristic of each section instead.
Invariably, the next question is always, “what does this way of stringing do exactly?” In its essence, the stringing pattern is a method that was developed to homogenize the amount of deflection and stiffness in order to create a consistent response over a larger percentage of the string bed. In its essence, proportional stringing attempts to mimic the result of the Yonex Isometric Head Shape, which is designed for the purpose of creating a string bed with less variation in string segment lengths. The overall effect is that you are treated to a much larger sweetspot and increased forgiveness. The result of each shot tends to be more consistent, offering greater depth on shots hit outside of the sweetspot requiring less precision.
Initially this seems like a positive thing in all regards, giving a larger sweetspot, easier power and plenty of comfort. So why is it that every player is not stringing this way? There are a number of reasons actually. The first being that people are, in general, creatures of habit, and change is something that they will not accept easily. They know exactly what the racquet will feel like if they take it in to be strung at 56 pounds using the traditional way, but not only would a proportional string bed at 56 feel differently, it would play differently, requiring additional changes and testing. For some, this is an expensive prospect to change strings every few days until they find the right reference. In addition to fearing this change, it, quite simply, will always be different, and some players actually prefer to be punished for subpar performances as they feel that it forces them to focus.
While the goal of proportional stringing is to create a string bed with equal deflection despite the location of impact along the face, due to angular and stretching constraints, this is not entirely possible. What you will end up with is a much larger sweetspot, but it is simply not possible to extend it all the way to the edge of the frame.
Please keep in mind that there are some negative aspects to proportional stringing as well. For one, it is somewhat time-intensive for the stringer, as well as being more prone to error. Also, due to the fact that the cross strings are much shorter than the mains, and thus are tensioned lower accordingly, you will be placing a bit larger percentage of the overall stresses on the frame in the longitudinal direction. This can weaken the frame in extreme cases or cause distortion, resulting in a more rounded head shape. Also, due to the purely mathematical nature of tension selections, it is best to be able to use a machine that can be set in increments of a tenth of a pound, but small rounding for less precise machines will not greatly affect the final product.