Complex sentence: They collapsed in 2007 to miss the post-season by one game and also missed the postseason by one game again in 2008, and they finished below.500 in the next six consecutive seasons (2009--2014).
Split into simpler sentences: They collapsed in 2007 to miss the post-season by one game. After a similar, albeit smaller, late-season collapse, they missed the postseason again by one game in 2008 They then finished below.500 the next six consecutive seasons (2009--2014).