I got a professional private tennis lesson by Jason, certified with USPTA.
But unfortunately, I realized I chose wrong instructor once I met him. He is beer belly guy and actually could not catch up even my warming up….

He may be good professional player once and fortunately maintained great service, so I took intensive service only lesson. It was a disappointing time for me, but I learned USTPA is meaningless and I have to work hard on finding proper pro-instructor!