How to choose a string

For many recreational tennis players choosing a string can be a real challenge.  That's why it's important to find a qualified racquet technician to help you navigate through the maze of strings available. Breaking it down into the types of strings and how they work in a racquet is really the best way to help the average player gain a better understanding of strings so let's start there.

String Types

There are 5 basic types of string. Although there are literally hundreds of strings on the market, all of them will fall into one of the following five types:

    1. Nylon - often referred to as synthetic gut
    2. Polyester - TV analyst like to call this the "new" string although they're not new at all
    3. Natural gut - unlike any other string because it is not made from a synthetic material
    4. Kevlar - think bullet proof vests and you get the idea
    5. PEEK - a Zyex based string with extremely high elongation (stretch)

Power & Spin

Always remember this; strings do not create power or spin on their own. Don't be fooled by marketing slogans like "Add more power to your game" or "Increase your spin with this string" etc.

Power and spin are a direct by-product of how you swing the racquet. If your retailer tries to sell you a string under the premise that it will give you more spin or more power you would be well advised to say thank you, turn around and leave. That retailer is not the knowledgeable retailer that's going to be able to provide you with the professional advice you deserve. Sure, there are strings on the market like natural gut that can give you additional pop on the ball because of the very nature of the string but natural gut is unlike any other string. That's why natural gut strings are very expensive BUT, that power still depends on how you swing the racquet. Polyester can give you more power and spin too but ONLY if you have the capability to produce the extreme racquet head speed it requires to do that, such as that of many top professionals. Unfortunately for us mere mortals, we just don't swing the racquet like those players do. So yes, in some instances string can give you more power or spin BUT remember it's all in direct relationship to how you swing the racquet. There are also other factors at play here such as the overall weight of the racquet, the balance, stiffness, string tension and the stringing pattern of the racquet but let's save those factors for another discussion. Right now let's focus on learning a little bit about string.

A basic understanding of string characteristics

Tensile strength relates to how far a string will stretch in a straight line (pull) before it breaks and this relates to durability when it comes to tennis string. Elongation is a string's capability to stretch and this is where a soft string with a lot of elongation can be a benefit to recreational players. When a string stretches at ball impact it absorbs energy and thus, when it rebounds it returns that energy to the ball increasing the power of your shot. That string's ability to stretch and then return to it's original shape (or as close to it's original shape) is called it's elasticity. All strings will stretch from point A to point B but it's a strings ability to return to point A that dictates performance. In this category, natural gut is king.

Stiffness in a tennis string means the string will have less elasticity and it won't stretch as much. So, for instance, we know that polyester is stronger than natural gut, BUT the difference in elongation is HUGE because the polyester string is very stiff. If you take a traditional stiff polyester string and compare it to a nice natural gut by doing an elongation (stretch) test you'll see that the gut will stretch as much as 5-7 times more than the poly.

Elasticity also equates to "dynamic stiffness," or a string's ability to snap back after impact (think "rubber band"). The higher the elasticity, the more power the string returns to the ball. When you have low elasticity the ball flatness out on the strings and loses energy and therefore, this reduces the power in your shot. The exact opposite is true for top professionals because since the ball flattens out at impact it allows the pro to get away with a very aggressive swing (think high racquet head speed) and they can create enormous power that way. It also means that there's additional spin with that high racquet head speed that in turn, brings the ball down into the court at the very end of the shot (think Nadal's topspin) Remember too that the higher the elasticity, the less impact shock and vibration on your arm and elbow which is important for anyone with wrist, elbow or shoulder issues.

We're often ask by recreational players if they can use a polyester string and the answer is yes however, it's extremely important that your technician understand exactly how stiff the string is so they can choose a proper tension. It should be noted too that at IART we do not recommend polyester strings for junior players. There are a lot of other options out there for juniors before moving them to a poly string and we feel that's the better route to take to protect from injury and arm issues in young players. Members of the IART community have access to our string characteristics data base that gives them information on a strings elongation and tensile strength so they can navigate to the right choice for you and your racquet.

Modern day polyesters, for the most part, are very stiff to begin with so they don't need high tension to maintain control but rather, they need to have the tension reduced to generate power. We're now seeing touring pros using polyester string in the 35-45 pound range to accommodate their excessive racquet head speed so think about that for a minute. If the pros are going that low and they have a much faster racquet head speed than you do then why be afraid of experimenting with lower tensions and poly. If you're anxious to try poly I would recommend that approach from the very beginning and remember, you can always increase the tension incrementally after that first string job. By following those simple guidelines it means you can use poly safely as long as you're willing to experiment with extremely low tensions.

The International Alliance of Racquet Technicians is a global organization and we have a list of qualified racquet technicians that you can search to find the closest one to your area. Just go HERE to access the list to find a stringer that's qualified and ready to help you find the right string for your racquet!


Written by Tim Strawn

Executive Director, IART

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