With each postseason expansion throughout MLB's history, the value of division races has diluted. In the wild-card era, you can finish in second place -- or even third or fourth -- and still win the World Series.
Does that make September less exciting? There's no doubt it brings more teams and more fans into the mix. And a big game is still a big game, even if there is slightly less tension in a Red Sox-Yankees or Mets-Phillies series than there otherwise might be if both teams already know they're going to make the playoffs.
Thus, we're mostly left with wild-card races and battles for seeding to occupy our time and scoreboard watching.