While I broadly agree with them, let me offer two caveats for smaller market non-viability: Green Bay Packers & Saskatchewan Roughriders. It isn't inconceivable a small market (on its face) earns somewhat fanatical loyalty. Maybe they only get to a Pennant race once every 25yr, a World Series once in 50--but that's not unheard of, either, is it? And it's not like the Cubs, White Sox, Indians, or Mets folded...Annotated the above list with my own highly idiosyncratic comments about the plausibility of major league baseball in the cities in question.