Starter Joba Chamberlain was taken out of the Yankees-Blue Jays game yesterday when he reached his pitch limit after 2.1 innings. He gave up four walks in that span, continuing the control issues he’s had all year. What can we expect from him as a starter?

Chamberlain worked twenty games from the bullpen before his start yesterday, and has posted an 11.42 K/9 and 5.19 BB/9. The strikeout rate is down a bit from last year’s 12.75, and the walk rate is much higher than the 2.25 he posted in 2007 (it’s also higher than anything he threw in the minor leagues). He’s pitching into a .284 BABIP so far, and has batted ball rates vastly different from last year:

His high ground ball rate this year is a great thing to see, and would be indispensable if he could sustain it for the remainder of the season. As you’ve already read many times if you’re a New York City-area sports-page reader, Chamberlain has been working on throwing more curveballs and changeups this year in preparation for his move to the starting rotation.

I would guess that his attempts to add (return might be a better word, as they’re pitches he used as a starter last year and in the minors) these pitches are part of the reason why his control is worse this year, and we might see his walk rate be reduced as the year goes on. Likewise, his new (old) pitches might help sustain the ground ball rate, though with it being so much higher than his previous numbers, it’s hard to see how it wouldn’t start to fade (and, conversely, the line drive and fly ball rates tick upward). UPDATE: Jonathan Hale of Baseball Digest Daily has more on the pitches Chamberlain used yesterday.

All in all, he looks to still be a very good pitcher going forward, though with a few warning signs, and with the expectation that his numbers might start to look a little worse, though still good (The Hardball Times has his xFIP at 3.20, which is still a little higher than his current 2.42 ERA). The low pitch count restriction (it appears the Yankees are going to keep him at about 60 or 65 pitches for now) means that the outcomes of most of his starts are going to rely on the New York bullpen.