His fundamentals are very solid as his wrist action is perfect. I'm always amazed by how fast these guys can drop the racquet head and crush the ball repeatedly over and over while keeping the ball in the court. It's much more difficult to do than the slow motion video makes it out as preparation, footwork, shoulder rotation, etc has to be fundamentally solid. It's really difficult to be that disciplined at the club level as no matter how much I practice, the bad habits always seem to take over when the ball is coming fast at you. Tennis is hard.