So sports with minimal physical exertion like pool and croquet aren't sports?
Is chess a sport?

Been there. Done that. Seven months ago.
http://www.chess.com/article/view/is-chess-a-sport
Better reading than this thread. Shorter too.

Sure, why not? They seem to consider poker as a sport. It's constantly on ESPN and other sport TV channels. Why should Chess be any different?
The fact that some activities can be performed better when one is physically and mentally fit (surely this applies to just about any activity, come to think of it) does not make them sport. To describe card games like poker as sports is absurd. To point out that chess involves players in moving their pieces by hand and that this qualifies as the required physical activity is surely to mock the whole argument - which is maybe what it now deserves. The fact that chess is shown on ESPN simply puts it together with countless other non sports which feature on sports programmes.

Yet another invitation to join your mutual admiration society?
Surely you're joking Mr. Feynman?

Chess is hyper-competitive, borderline sport. "Part Art, part Science, and part Sport" (direct quote), according to GM Gulko, and former U.S. Champion.
Play 8 OTB rounds in just 4 days and you will learn quickly how physically draining the royal "game" really is.
And these forums resemble a mosh pit at a Grateful Dead Concert. They're quite "physical" as well. Nuff said ??
Why should GM Gulko's view of what is a sport have more validity simply because he is an expert chess payer? Playing 8 tough games in 4 days may be mentally tiring and draining, but it is most certainly not physically demanding.

Then you have never played in a 4 day OTB tournament. Duh?
8 rounds, 2 games per day, 6 hours per game. Do the math.
Everything is tiring when you're pushing 70. Boris Gulko couldn't come close to competing in an actual sport.

Anything can be tiring when you do it six hours consectutively, twice a day, for four days. Solving crossword puzzles for six hours a day, twice a day, for four days can be tiring. That doesn't mean solving crossword puzzles is a sport.
I don't agree that chess is a sport at all. It's a board game. It's a highly competitive board game with a rich history and a large client base. But it's still just a board game. and board games aren't sports. Playing Monopoly, even in a tournament setting, isn't a sport.
Of course, I suppose it comes down to your "definition" of a sport. Here's one: a contest or game in which people do certain physical activities according to a specific set of rules and compete against each other.
That description does not fit chess. Not to me.
No matter what effect playing chess might have on one, it does not involve significant physical effort, which sports definitely do.
If I were to go and play in a tournament of the kind you describe, I very probably would end up mentally tired, but definitely not physically affected in any significant way. Apart from anything else, I very much doubt that tournament chess games average anthing like 6 hours each.

Anything can be tiring when you do it six hours consectutively, twice a day, for four days.
Not sleep.

If I were to go and play in a tournament of the kind you describe, I very probably would end up mentally tired, but definitely not physically affected in any significant way. Apart from anything else, I very much doubt that tournament chess games average anthing like 6 hours each.
most games I have played was 2 hours each and in some team chess we had 2 hours each for 40 moves and ½ hour each . up to 5 hours.
after 3 hours of playing you start to make blunders if you do not stay alert somehow.
-Chess requires physical usage of the hand.
Moving the piece is only a physical representation of a mental activity; i.e. it's incidental. Not to mention that chess can be played blindfolded, when there's no need to move a piece at all. Or do you think it's not a sport when played blindfold, but suddenly becomes a sport otherwise. Or maybe you think that since you have to perform the physical act of breathing in order to play chess, that qualifies it as a sport?
When you play blindfolded you have to think, your heart has to beat, and your lungs have to breathe, among other things. All this burns more calories than moving your hand.
No wonder Bobby Fischer can't play blindfold chess anymore!