Boston and Atlanta are both on the brink of blowing their post-season chances, despite being sure things just a few weeks ago. A look at past examples of MLB collapse.

Reuters

On Sept. 1, the Boston Red Sox led the American League East by half a game. They were a full nine games ahead of the third-place Tampa Bay Rays, their closest pursuer in the race for a wild card spot in the playoffs. Meanwhile, the Atlanta Braves held their own nine-game lead in the National League wild card race. Now both teams are in the midst of potentially historic collapses, stumbling towards the regular season's finish line like an exhausted triathlete as they desperately try to hold on to a postseason spot.

Both teams still control their own fate, holding two-game leads in their respective wild card races with six games to play. But if the Red Sox or Braves should falter in the coming week, they will join the ranks of teams that had a playoff berth all but locked up, only to choke it away.