1 A simple rule of thumb:
Restring your racquet as many times a year as you play, on average, in a week.
When you tap a strung frame against your hand, dead strings will produce a “thud”, while fresh strings produce a resonant sound or “ping”. So, if you don’t har a ping, it’s time to restring.
3. Haven’t Played
Even if you don’t hit one shot, your racquet will lose tension. So, if say you haven’t played for a few months, you should restring. Even a great racquet won’t perform if your strings have lost tension. After all, your strings are the only thing that touches the ball.
4 No Control
When your strings lose tension, you have less control. So, missing that cross-court shot by four feet doesn’t necessarily mean you are worse than you were last week. It could easily mean that your racquet needs new strings.