Atlanta: http://www.sportsclubstats.com/MLB/National/NLEastern/Atlanta_ChanceWillMakePlayoffs.html 99.64% on August 25th Boston: http://www.sportsclubstats.com/MLB/American/ALEastern/Boston_ChanceWillMakePlayoffs.html Strangely enough, Boston's chances also peaked on the same day, when they hit 99.90% on August 25th. nate silver did an article about the biggest collapses in baseball history when he was still with BP... the 1995 angels had the biggest choke, because on august 20th they led their division by 9.5 games and led the next-closest wild card contender by 12 games. they were 99.988% likely to make the playoffs, or 8,332-to-1 to miss it. the 2007 mets ended up blowing the division, and were 99.8% likely to make it. i don't think there were teams with odds that high in 2008, 2009 or 2010 that blew it, so the red sox would be the second-worst choke in MLB history. the braves would be #4 or #5, depending on whether the red sox miss out (the braves would also trail the infamous 1951 dodgers).