Im not sure about this, but when they first built the stadium i was wondering the same thing, and i remeber hearing a sports caster (dont remeber who though) say that hella long ago a few stadiums had hills for warning tracks, so the astros were just trying to go back the the "good old days". im not sure about this though i just remember hearing it somewhere. The other stupid thing about their hill is the fucking pole in the middle of it. But no matter how you look at it, they got a pretty crappy stadium.