Hi, This is my Yonex racquet's factory spec: Stringing Recommendation Main: 14-16 lbs. (6-7 kg) Cross: 16-28 lbs. (7-8 kg) By looking at this, how much tension does the company recommend for the tension? We usually ask for a shop to string it at a number of pounds. How a stringer breaks the tension into Main and Cross tensions? Thanks.