Baez is going to be a really good defensive 3B. I think it plays into his skillset (and build) better than 2b and even SS. He has really quick hands and good, but nowhere near great, range. And I think it will help him not having to think as much on defense. Not that he's stupid or anything, but there's not going to be a lot of "should I charge or wait for the hop?" type decisions to make. If his bat makes it, I have a hard time seeing him being less than say, Aramis Ramirez defensively in his prime, which was very good.