I agree. When there is some prize you compete for your mentality is the same as any other athlete's. You train hard, prepare for the tournament, always strive to become better etc. But that's true only in multiplayer games when you compete with others. Single-player games are just an escape for me, a way to break free of real life problems.
Sport: An activity involving physical exertion and skill in which an individual or team competes against another or others.
Game: A form of play or sport, esp. a competitive one played according to rules and decided by skill, strength, or luck.
Gaming is not a sport, and neither is chess or poker. All of them require skill of some sort to do well at or become professionals at, but none of them need any physical exertion.
Well it's the classic definition of sport. Maybe after 10-15 years it'll change...
But that's not the point. I think sport can be called any kind of activity that encourages healthy competition and requires some skill from the participants be it mental or physical. Sport shapes mentality and professional players that play at tournaments (less on local and more on international level) have that mentality. Sure anyone can game but to compete with professional players you need to commit yourself to a game.
I'm fairly decent at poker and chess, yet I cannot consider them a sport, at least for most people. A sport to me, requires an amount of physical exertion. That is not to say that a certain amount of physical stamina is not helpful in the games. Former world chess champion Gary Kasparov's training regiment included physical activities such as running, swimming, football (soccer), and cycling; this was in addition to his chess studies. There is no doubt that this physical activity helped his endurance at the board, and kept his mental energies fresh. But, nevertheless, I can not consider chess, poker, or video gaming a sport in and of itself.
To me there are 2 kinds of sport. You have the classic physical sports, and the mental sports consisting mainly our of newer concepts but also older ones like chess, cardgames that are not based on random luck, classic boardgames that are not based on random luck, and videogames that require a certain amount of skill and intelligence to complete.
Ps. Jet Li is amazing, I love his acting.