For the past three seasons, the Houston Astros have ruled the National League Central and have represented the National League in the World Series in each of those past three years. 

And now, well, both teams are currently occupying the cellar in the National League Central.

Such a collapse was inevitable, perhaps even predictable, when you see how both teams have fallen flat on their faces for much of the year.

What was the root cause of the collapses?

The reasons are many, but here are the three root causes,,,

1. The Improvement Of The National League Central.  Many of the analysts will state that the NL Central is the weakest of the six divisions.  However, consider the fact that the Brewers, the Pirates, and the Reds have all improved while the Cubs, who have also been down as of late, have begun to rebound after their down period.  Both teams found themsleves unable to dominate their compition as they once could and soon
2. The Loss Of Talent In The Farm System.  Both teams have sacrificed a lot of talent to sustain their winning streaks.  The Cardinals have traded away the likes of Dan Haren, Daric Barton, Kiki Calero, and other valuable prospects to acquire Mark Mulder, Jeff Weaver, and others to bolster the main club.  The Astros have been even worse, surrendering John Buck, Octavio Dotel, Jason Hirsh, Wily Taveras, Taylor Buchholz, Mitch Talbot and Ben Zobrist for expensive one year rentals of Carlos Beltran, Jason Jennings, and Aubrey Huff, respectively.  The result has been the depletion of their respective systems and no impact talent left in the upper minors to draw upon when veterens are struggling or are ineffective, or even to make more trades.  Neither team's situation is going to get better when you consider the draft pick compensation that has been lost due to the next reason..
3. Questionable Free Agent Signings.  Both teams have also let players go because of various reasons that are looking more and more terrible as time passes.  The Astros have allowed Andy Pettitte, a horse in their rotation, to leave to the Yankees.  They brought in Woody Williams and Preston Wilson, both of whom were or currently are performing badly for H-Town.  As for the Cardinals, they allowed most of their rotation to depart via free agency, such as Jeff Suppan, Jason Marquis, and others, for fear of paying too much to retain them.  That arguement looks even worse when you consider the fact that not only are Suppan and Marquis, but that both are doing it for division rivals.

Can both franchises pull themsevles out of a rut?  It's possible, considering that both teams are littered with players that are underachieving.  But the more time that's passing, the more and more it looks unlikely that it's going to happen.