I'm an occasional chess player, and in my opinion, it depends on the player (or on the player's mood): if he plays 'just for pleasure', without thinking a lot I would say it' is more a game, because you do not predict enough to do without luck, but hard players, with experience and intense mental working, almost not count on luck. Then, in the last one, it depends directly on players skills, and I think we can call it a sport in this case. I do not know how it is in another countries, but in France there is an expression which is litteraly 'spirit gymnastic'. An intense chess game is really tiring (most of the time, I tend to avoid that
), and as in all sport, you train a specific part of your body.
An exam can not be considered as a sport, because you only make rote learning, and answer to questions with that you had learn.
And I think it is interesting to bring up the question of videogames, especially with all the new technologies that emerging, some videogames require a lot of concentration, skills and good reflexes, therefore maybe we can call some of them 'sport'...however, maybe I'm wrong, gain reactivity in one videogame do not always help in real life, then we can say that there are better sports than others (healthy speaking)
.