Originally Posted by mace
I don't know the answer to this, so it's not a leading question . . . but how many pitches does Brandon Webb throw? Derek Lowe? I do know that Bob Gibson was just fastball-slider at least 95 percent of the time. It just seems that if the two pitches are good enough, they're good enough -- particularly for a ground-ball pitcher. Not that I wouldn't like to see Stewart develop his change; of course I would. I'm just not sure it's a prerequisite for being a starter in the big leagues.
I would say its a pre-requisite to have an off-speed pitch to be a starter in the majors, and you need to throw it with the same motion as your fastball(see Travis Wood for exhibit A). You need to mess with batters' timing. They are too good at the majors if they can anticipate the timing of the ball crossing the plate.
However, you don't need a changeup as much for relief. Batters don't get mutiple looks at a relief pitcher in a game so the changeup isn't as important. If Stewart learns to throw a deceptive changeup, then he will be considered a starting pitching prospect.