Year after year after year he slumps in the 2nd half. Not like he becomes useless but he does lose value. He's just slumping and the entire houston team is going through a bad team atm (except beltran).
Beltran is slumping too...Clemens, Biggio, and Lidge are the only players not slumping. Youre right about Berkman slumping though in teh second half, though i truly believe that he is going to grow out of that as he gets older.