The whole science of racquet stringing is very complex, but if explained properly, the average player should be able to understand the basics.

For some reason the United Kingdom is one of the few countries in the world where racquets come pre-strung. In many cases, these pre-strung racquets will be of poor quality and low tension (strung by 'hand' in the Far East).

There are a number of myths with string tension, firstly it is a misconception that the tighter the string, the more power the player will generate. As a general rule a tight string bed will offer more control (lack the 'trampoline effect'), while power can be obtained by a lesser tension.

If an average club player has their racquet strung at 30lb, it is highly unlikely that they will get anything other than 'tennis elbow' from that racquet. The standard range for a club player is between 15 - 24lb. The reason many of the top players use racquets at very high tensions is due to their strength and ability to strike the 'sweet spot' on the string bed, every time (the sweet spot is reduced as the string is drawn tighter).
As a rule of thumb, you should be looking to restring your racquet the number of times a season, as you play in a week!

Just because the strings have not broken, does not mean that they are still giving optimum performance. As soon as any item under tension is released 'creep' will start to take effect. Hence the racquet strung today at 24lb, will settle to about 19/20lb by tomorrow. The higher the tension in the string bed, the less durable the string becomes.

Modern racquets with their widebody sections and stiffer frames, work the strings much harder than in a conventional racquet. This is a consequence of the racquets generating more power. Other factors affecting the string durability are players who generate a faster movement of the racquet head (hard hitters), those who hit a lot of slice shots and the use of shuttles with a hard base.

The vast majority of racquets are strung with a 21 gauge (0.75mm) string. This offers a compromise between durability and performance. Thicker gauge strings will last longer while thinner gauges offer better performance (however, durability could be reduced by up to 25%!)

String movement is another common area of concern; strings do not need to be straight to offer maximum performance.
The only strings that do not move are cheap, standard nylon (monofilament) strings. These are prevented from moving by 'notching' into each other.

Multifilament strings and natural gut do not notch and will always move. This is a good sign and will never affect the flight of the shuttle.

Things to look for when getting a restring:

• Always ask if the grommets / buffer strip on your racquet are okay. It's a false economy to restring with damaged grommets or a worn buffer, because they protect your strings from friction and contact with the frame.
• Your restring should have no more than 4 knots. If it has, take it back and tell the stringer to do it again.
• Only the four outside strings should be noticeably looser than the others. If a central string is very loose, take it back.
• All strings at the throat of the racquet should be 'locked' in place by being woven under cross strings.
• Modern racquets are fairly fragile. When a string breaks it deforms the frame slightly and can cause structural damage. In order to minimize further damage, you should seek to have the racquet restrung as quickly as possible.
• Repairs (or 'patching' as it is sometimes called) should only be carried out as a very short-term measure. A broken string means that there has been tension loss over the complete string bed, which will never be regained with a repair.
• Conscientious stringers will keep details of your last restring enabling you to have the same string and tension without guessing.

On a final note, choosing a racquet stringer is best done by asking members of both yours and other clubs who they feel gives the best quality of service. Do not be afraid to ask your stringer questions, if they are the professional you think they are they will clear up any queries.