Well Braves and Red Sox after being the frontrunners for the majority of the season have both struggled with their pitching in the last month of the season. Red Sox in particular have looked terrible. Braves on the other hand just can't get any timely offense. Both Red Sox and the Cardinals have series with teams that have been rather sub par this year, if not awful. The Braves and Rays have series with teams that have already clinched their playoff spot which could mean easier competition, but of course still the Phillies and Yankees.
Hard to tell, but right now Red Sox and Braves still have advantage as really the outcome is in their hands. Win 2 games, and then it is up to the competition to win all 3. Can't tell ya how it'll end, but definitely another good end to a baseball season. Playoffs will be just as exciting.