I knew a little about Rich Harden, but I haven't had a chance to watch him pitch. I missed his first start as a Cub when he went 5 1/3 with 10 strikeouts. However, I just read this article on his mechanics and pitches. Check out how filthy his fastball / change-up combo is:
Scroll halfway down the page to the "Stuff" section.
I can't believe how similar those pitches look until a few feet away from the batter. No wonder this guy strikes everyone out. His stuff is bordering on unfair.