String Snap
The obvious one! The most common reason to change your string for the average player is when a string or multiple strings snap in the racket usually caused by a miss-hit. A mis-hit is one that is not within the middle of the racket where there is even stretch of the string around the impact zone. Although not the sole contributing factor, snapped strings caused by mis-hits are more likely to happen when using higher string tensions (24lbs+).