To me, Fritz needs to watch some del Potro matches and learn how to step to his left and unleash on a forehand.
All too often he’s content getting into backhand to backhand rallies, and while his backhand is solid, he needs to take control of the point early, and not relinquish that control. That’s the only way he’ll have a chance against Djoker.
Don’t get me wrong: I root for him to do well, but I want him to dominate the court like he should. His serve & forehand are good enough, but he doesn’t unleash as often as he should IMO.