Wait, you turned off the shot cam?? THEN YOU WON'T GET ANY ACHIEVEMENTS!!
As far as Jung Soo goes, I usually rotate button combinations, such as a top left spin and a top right spin (rotating each side of the table), eventually you should get a fast enough hit that he can't return.
First legit 1000 in Rockstar Table Tennis
First person to have 1750 in three different games