Originally Posted by tennisamba
can you explain me why?
It's a feel stick, and very soft. If you string it tight with poly, there will be no power and little responsiveness off the string bed, so you will have to swing fast to generate. Hitting flat with full poly is useless and painful. Hitting heavy topspin on hard court, invites getting attacked on the first short ball. Hence, you better be swinging fast, hitting topspin, and doing it on clay.