I've been wondering for quite awhile.. in terms of a professional (where you mastered all the skills and have the stamina), is it the accuracy?patterns?stamina?speed? that makes a player a winner/professional?
By definition, a professional athlete (regardless of sport) is one who makes his living (get's paid) to play that sport. Amateurs, either pay for their own play or get funding by a government, which is not considered pay, but corporate sponsorship would be considered pay. While the definition of professional actually has nothing to do with your skill level, it's also pretty obvious that only the best will be able to play a game/sport for a living. What makes a "winner" is a completely different topic.
If they get part of the sponsorship money then they would be considered professional. Also, professional tours are mostly for professional athletes. For instance, the ATP Tennis Tour is a professional tour, regardless of how good you are. The interesting thing about badminton is that even though it's an individual sport, players tend to be on national teams. The teams gather all the sponsorship money that comes in and the members of the team split it.
