I think it also has to do with the size of your room and seating arrangements, how comfortable it is to just sit around while not playing, or worse, while playing. Often I lose concentration due to the cluttered, people-everywhere nature of our room. That isn't half as bad as when I have my 7 other teammates there to "support" me, and now I'm navigating through them, and enduring an unerring "good leave" compliment after every miss. They mean well, but it doesn't help my game.
Then there's also the 7 teammates of my opponent 4 feet away, whispering comments about every position I leave myself in, flirting with waitresses, screaming about the UFC fight, and talking so much shit it no longer smells like cigarette smoke in there. So I've got to position myself as far from them as possible, and now when it isn't my shot I feel like I'm watching a cockfight in Mexico from 10 feet behind the crowd and wondering who's winning.
Some players come to play a game, say hello to their friends, have a drink, and roll out. I don't blame them -- I often wonder about the long term consequences I'll face for sitting around in the smokey pool hall with shitty dubstep music blaring until 1 in the morning twice a week because I'm stupid enough to be captain of two teams in two different leagues.
Think I may have gone off on a rant there. :sorry:
/fml