Yes, he has to get mentally stronger, but I think that's not the biggest issue. He shoots as straight as all but a handful in the men's game, but he is missing some features, especially in the areas of defense, kicking, and the use of two-way-shots. Until he's playing all the right shots, he won't be in the process of mastering all the right shots.
It is not uncommon for a young, really straight shooter, to never get around to becoming elite in the skills needed to beat players to the shot (the break, defense, kicking, jumping, using two-way shots, tactical conceptualization and general risk management). Today's brand of 9ball, with very tight pockets and a very narrow break box, requires a lot of grinding, and the big winners are those that complement their superior offensive execution with the knowledge and skills to beat opponents to the shot.
Even if he becomes mentally stronger and has the work ethic of an SVB, Gorst or Filler, he won't get to the top unless he becomes a more well-rounded player.
Wishing him well in his continued pursuit of excellence.
