I have recently started stringing racquets for a few people on my team. I was wondering what causes a racquet to crack during stringing and what measures I should take to prevent this. I have been stringing for over 5 years now and I haven't had a racquet crack. Just want to know if I am lucky or doing it right. Also, if doing a two piece string, why start at top of racquet and not throat? When you do a one piece, the crosses start at the throat.