The author claims football and basketball skills can be mastered by practicing alone? What planet did the author come from? This is a ludicrous as saying soccer players can master their game by practicing alone.
Team sports require practice with the team as a group to achieve best results. Surely the author doesn't suggest a football team can achieve greatness on offense or defense with each player practicing by themselves? The same with basketball, maybe the author believes all 5 players can just run individual drills and magically become a good team?
Basketball is really the only sport you can practice alone. Shooting is not a skill that's developed in games. Ever heard the term "gym rat"?