is "flow" just a near-synonym for "be here now? so not thought is the enemy so much as either future-oriented thinking (planning, anxiety, anticipation) OR past-oriented thinking (memory, regret, retracing footsteps etc) - anything that detracts/distracts from the moment-to-moment thinking
i have played games maybe a dozen times in my life but i should imagine as Corpsey suggests the flow-state is a major part of the attraction
i wonder where gambling fits in this - it's not quite in the moment but there's a tremendous tension directed towards a moment to come (the horse crosses the line, the hand of cards is revealed) but it's so imminent and so tensed that all else is blotted out - all other worries in your life contract to this single Worry. I wouldn't know, i'm not a gambler, but I did just recently watch California Split, the great Altman film about addicted gamblers
those automatons you see at the fruit machines in Vegas are in a kind of flow (which begs the question of whether thre are state-of-grace flows and profane, profoundly-fallen flows)
(in Vegas there is actually a college of Gambling Studies, a grim looking building on the outskirts of town)