This is just a thought that has been bumbling around in my head the last few weeks, but I think it's well-formed enough now that I can turn it into a theory. Or at least, to quote my wood shop teacher in 8th grade (Mr. Weldon, whom I hope is still alive but to be honest I'd bet the under) "something that resembles something that looks like what could possibly be the very beginnings of" a theory.
One of the main ways that your average casino poker player gets better is by observing other players in his game. He doesn't read books, he doesn't post on two plus two, he doesn't talk about hands with people who have beaten the game in the past, and he probably doesn't even think back about his own play in an objective manner and apply changes he thinks will win him more money. He just plays and watches what other people do. My theory is that if he finds a particular player who either always seems to win or is very difficult to play against, he will start to incorporate aspects of that player's game into his own. For example, if Joe decides that Bob is a solid, tough opponent and Joe notices that Bob never open limps, then it's possible, in fact likely, that Joe will start open limping less. At this point I feel the average response is probably "no shit sherlock." Fair point, this is pretty obvious. When people play games they try to copy what the better players do. But there are two interesting points.
Often times the skills required to beat one game are very different from those required to beat the next game up, or at least not enough by themselves. For example, you can probably beat a lot of green chip casino games (6/12 and 8/16) and still play way too many hands preflop. The reason for this is obvious; most of your opponents are playing so many hands that your errors are very small, or perhaps even not errors at all (game conditions dictate which hands are playable preflop, and the default set of such hands changes as you move up in stakes). So what does this mean? People who copy winning players and then try to move up will often be woefully unprepared for the next level and get absolutely slaughtered.
While the first point is interesting, the second one is more what I was thinking when I decided to write this post. If there are no "good" players in a game, none of the regulars will ever get very good. And if a game isn't big enough to support a professional, then really nobody great will ever play it for very long (he'll either move up after crushing it for a few hundred hours, or never play it in the first place). With just a little bit of logic and faith, you can use these statements to claim that live 8/16 games will always be awesome, because nobody will ever crush them for long enough for the regular players to learn enough from them to become solid winners themselves. At least sorta. The same token doesn't really apply to 15/30 and 20/40 games, because these are large enough that some people (myself included) play in them regularly with the expectation of making enough money to at least support themselves. The risk being run is that if enough good players populate these games, the bad players will eventually start picking up their tricks and improve themselves.
OK that's all I've got.