After newly strung racket can break string within few seconds or it will last you for months without any problem.  Must take care of the racket by hitting ball in middle of the racket. Normally good players strings wears out never breaks.

Even with improvements in string technology, breakage is as common as ever, due to the increasing popularity of thinner strings and high stringing tensions. In order to reduce breakage, it is important to understand that it has several different causes. Each may be addressed through a different approach.

The first and most common cause of breakage is stretching the string beyond its elastic limits-similar to pulling a rubber band until it snaps. This usually occurs on one of the central main strings, within an inch or two of the head.

The sweet spot is the most resilient-and hence most powerful-area on the racquet. No matter how clever racquet designers may be, they’ll never be able to make the sweet spot extend right to the edge of the racket head. Every time you mis-hit outside the sweet spot, you’re stressing a relatively unresistant section of the string. There’s simply not much string to stretch between the shuttlecock and the edge of the racquet, and if the forces are too great, it snaps.

Stringing at lower tension will reduce the incidence of this problem, as will the use of a thicker string. But don’t change both at once. Approach the problem systematically, change one or the other, and play on the new setup for a few weeks before deciding what your next move should be.

Other relatively common causes of breakage are string-to-string abrasion and cutting. Every time you hit the shuttlecock, the cross strings pound against the main strings. In time, they can cut through the outer jacket and into the core. Likewise, “cutting” and spin shots cause the strings to “saw” back and forth against each other, with much the same effect.

Again, thick string withstands this longer than thin string, but there are better ways to resist abrasion and cutting. Some strings have wear layers instead of the more common single wear layer. Naturally, more will resist abrasion longer.

Over-stressing, and string-against-string forces are inherent in the game. They’re not entirely avoidable, but you can take steps to reduce their effects. Other types of breaks can be due to frame/grommett defects or carelessness, and can be completely eliminated with proper attention.

A broken, split grommet may present a sharp edge that can cut into the string. If the grommet is missing, the frame itself may cut the string. Next time the strings are out of your racquet, check the grommets. The simple solution is to make sure the grommets are sound. A new grommet strip may cost around 10 bucks: well worthwhile if it saves you a $15-25 stringing job. If the proper grommet strip is unavailable, your stringer may be able to install a piece of plastic tubing as a temporary repair.

Temperature-related breakage is common in cold climates in the U.S. and Europe. Cold causes the string to contract, significantly increasing its tension. Furthermore, nylon, which is normally a very resilient material, becomes brittle when it’s cold. For both of these reasons, if a strung racquet is taken directly from a cold car trunk and immediately put into hard use, the string could shatter.

The solution to this problem is simple. You can protect the racket from the cold by transporting it in the heated cab of the car, and/or by carrying it in an insulated racquet bag. If the racquet does get cold, give it several minutes to warm up before putting it into play.

Even with proper care, some string breakage is inevitable. As a string ages, it gradually becomes abraded and loses resiliency. Your best bet is to restring before such degradation occurs: newer strings perform better, and you’ll be surprised less often in the middle of a match.

Synthetic strings made of nylon and polyester often last a long time, but virtually all of them go “dead” after about a month, whether or not you play. Just because the string isn’t broken doesn’t mean it’s still good. Natural gut, while initially more expensive and somewhat more fragile, is good almost up to the moment it breaks.

When strings go “dead,” they don’t lose power, they lose tension. This means that you have looser strings, so the ball goes farther for the same effort, with less control. You also lose control because the strings feel differently than they do when they’re fresh, so you either have to adjust your game, or content yourself with not playing your best.

The “rule of thumb” is that you should re-string your racquet(s) as many times per year as you play per week (unless your strings break, of course). Unless you are using natural gut, this is not nearly often enough. I think you should aim to re-string every month. That way, your racquet is always playing its best, and you won’t have to adjust your game nearly as much, to compensate for the difference in feel between dead strings and fresh strings. If once a month sounds too often for the amount of tennis you play, play more tennis!

String facts , Generally speaking :

1. Lower string tensions generate more power.
2. Higher string tensions allow for more ball control (for experienced players).
3. A longer string (or string plane area) produces more power.
4. Decreased string density (fewer strings) generates more power.
5. Thinner string generates more power.
6. More elastic strings generate more power.
7. Strings that produce more power will also absorb more shock load at impact.
8. Softer strings, or strings with a softer coating, tend to vibrate less.
9. A stiffer stringbed tends to produce more spin.
10. The more elastic the string, the more tension loss in the racquet after the string job.

Racquet care is mostly common sense:

• Don’t expose it to extreme heat or cold such as by leaving it in your car in summer or winter. A hot car can soften a graphite frame enough that the string tension will pull it out of shape.
• Keep it out of the sun when not in use.
• Don’t throw it, bang it, or sit on it.
• Avoid scraping it while picking up balls.
• Put protective tape over those parts of the outer surface that you might scrape reaching for low balls.
• Install a fresh over grip whenever your grip gets slippery. Having the racquet slip out of your hand is a common cause of breakage, and it can injure another player.
• String within the recommended range. Exceeding this range can break your frame and will usually void your warranty.

Stringing is a little more complicated. I’ll try to answer the three most common questions:

1. How often should I restring?

The conventional rule of thumb is to restring as often per year as you play per week, but no less often than twice per year. It won’t hurt your racquet to restring less often, but your strings might lose their responsiveness.

2. What’s the best string?

There’s generally a trade-off between resiliency and durability. The most durable strings, made of Kevlar, are extremely stiff, and the next most durable type, certain polyesters such as many of the Luxilon strings, are also stiffer than many other types. Highly resilient and/or thinner strings, which many players find offer a better feel, tend to break faster. Many strings have durability and resiliency (or playability) ratings on the package.

Some players who can tolerate a stiff string bed but want to moderate the stiffness somewhat use Kevlar main strings with synthetic gut cross strings. (Mains wear out much faster than crosses and are almost always the ones that break.) In such a hybrid system, many will string the crosses ten pounds tighter than the mains so that the stiff Kevlar in the mains won’t prevent the more resilient crosses from providing some rebound effect on the ball. If the Kevlar were as tight as the synthetic gut, its stiffness would not let the ball ever “get to” the synthetic gut.

If Kevlar and its Aramid cousins are too stiff for you, the next most durable strings, polyester-based, such as the Luxilon Big Banger ALU Power 16L, are a lot more resilient.

Finding strings you really like can require some experimentation. If you start by deciding how much durability you require, then you’ll be able to stick with the results of your play-testing. There’s no point falling in love with highly breakable strings if you’re a big spin hitter who can’t afford to chew through a pair every week. The performance of Kevlar strings seems fairly consistent across different brands, but other types of string are less predictable. Two brands with similar resiliency and durability ratings can feel quite different. If you bring comments such as “too springy,” “too soft,” or “too stiff” to the stringing technician at your pro shop, he or she should be able to point you toward strings that feel more like what you want.

2.. What’s the best tension?

Generally, tighter strings offer more control, looser strings more comfort. Looser strings also seem to have more power because they tend to hit farther, probably due to their prolonging contact with the ball while the racquet moves upward with the stroke. String tension has a profound effect on the way a racquet performs and feels. I’ve seen lots of players hate a racquet strung at one tension, then love an identical frame strung differently. (This is a good point to keep in mind when trying racquets you’re considering buying.) There’s no single best tension, and the pros offer little guidance, with a huge range in their preferred tensions and no apparent correlation to style of play.