spinning

Harvard has a paper to study how zhang jike's ball is spinning ........ ( it was accidentally found by one of the fans ) The author is the doctor of harvard university school of engineering and applied sciences , the topic '' bend it like zhang jike '' is similar to an indian -british movie...

Hi everyone, I am a high toss server. I will have my palm open and the ball resting on my palm. I will then toss it up, not roll it off my fingers, and then hit the ball with spin. When i was playing, my opponent said my serve is illegal because my ball is spinning when tossed up. Wouldn't my...