Poker again last night. The drearier writers on the subject start from the assumption that the only point is to win money; I happened to do so this time, but that's not the major aim. Financially it's a zero-sum game, but emotionally it's decidedly negative-sum, since the pain of losing a certain sum of money (it doesn't matter how much, provided it's enough to hurt) is not nearly balanced by the pleasure of winning the same amount. The real gain, the real high comes at the point where you push all your chips into the pot and then wait for your opponent to call or fold. For this period of time, which might be a minute or so, there is a tremendous feeling of release. You have no more decisions to take, and all the pressure is on him, as he comes to terms with such things as: how good he thinks his hand is, what your hand might be, what he thinks you think he has, how much he fears you, how much he thinks you fear him, what has happened in the past between the two of you, and so on. Really the relationship between you is more important than anything, including the actual cards.
I can't achieve the same effect with roulette or racing. In either, you can bet all your money and then there is nothing to be done until the ball falls in its slot or the winner passes the post, but there is no antagonist, so no agon, so no release, just boredom.