The right string tension can change your game, for the better. It will make you a more skilled player, it will give you more accurate shots, allow you to recover faster and a whole host of other things will be improved in your game so let’s find out!

Before you choose a badminton string, here are some basic facts and terminology you should familiarise yourself with: All strings stretch, like an elastic, and therefore your strings will begin to lose tension (known as "tension creep") starting from the day it’s strung. Every racquet has a “sweet spot.” This is an area on the string bed which will give you the most power. Depending on your level, there are certain string tensions that are more appropriate than others. Beginners lack the technique and is more likely to mis-hit the shuttle on the wrong part of the string bed, so it is recommended that they use a lower tension because the lower the tension, the bigger the sweet spot. A higher tension will provide more power and control only if you can consistently hit the sweet spot. The downside is, the strings will break more easily if a mis-hit occurs because of string tightness and how they’ve being stretched. As a player becomes more consistent, they’ll benefit more from a higher tension because the shuttle will travel off the string bed faster, giving them control of the shuttle.
String tension relating to power and control

Much of the power in a Badminton shot comes from the string. So, it’s very important to know how string tension can change your game. By adjusting the string tension, you can adjust the amount of power or control that you get from any string, thick or thin.
What if you are playing with a lower tension (18-23lb)?

So what a lower tension means is a softer (looser) string bed and less feeling of the shuttle which results in less control and placement -the racquet will have a softer string bed which means that there is more "bounce/repulsion" from the strings and therefore the player can easily get power without using much strength -a larger sweet spot that is more forgiving and requires less accurate strokes to generate power -the strings are more durable and less prone to breakage from off-centre miss hits at the sides of the string bed.
What should you do with this info?

Lower tensions are more suited for beginners who do not have good hitting technique and require more power in their game. When playing with a higher tension (24-30lb) means -a harder (tighter) string bed and thus more feeling of the shuttle which allows for more control and placement, the player will need to be more accurate and consistent with their strokes in order to generate power due to the smaller sweet spot. The racquet will also have a harder (tighter) string bed meaning there’s less "bounce/repulsion" from the strings and therefore the player will need to input more strength to generate power -the strings are less durable and more prone to breakage from off-centre miss-hits at the sides of the string bed.

Higher tensions are more suited for advanced players who have good hitting technique and require more control in their game.

They usually have a few different ranges depending on the racquet itself, 17-22, 20-27, etc... This recommendation is there to ensure that the racket does not break when stringing. People who choose to go over the limit may subject their racket to damage under the immense pressure from the high tension of the strings. Professional players often string way outside the recommendation at 30lbs+. These players are sponsored and do not have to pay for their if it breaks so unless you are sponsored, don’t string outside the recommended tension and to do so at your own discretion. The recommended tension is also there for warranty purposes. Stringing outside the range will void the warranty. A common mistake most people make is to string at too high of a tension because of their ego. Since it is harder to generate power at high tensions, the player will often use excessive force in order to generate power and may result in an injury to the shoulder or they may develop tennis elbow.
Here are some suggestions for string tension for different levels of play:

Beginner: 17lbs-20lbs

Intermediate: 20lbs-24lbs

Advanced: 24lbs-27lbs

Professional/International: 27lbs – 30lbs+

If you play with plastic shuttles, it’s recommended to lower your tension by 1-2lbs. A plastic shuttle generally requires more effort to clear to the baseline because they are heavier and fly differently compared to feather shuttles. Lowering the string tension will give you the extra power that you need to help you with clears.

With all that info you should be able to find the perfect tension for your level of play and style. Happy hitting!