Richard Durrett has a piece up at the ESPN Dallas blog on Yu Darvish's first couple of days in camp, discussing him throwing to Mike Olt and Jake Skole in batting practice today and including some quotes from an anonymous scout:
I didn't get to see him live before this week and what I've noticed right away is the balance and delivery. Many guys will fall off the mound to one side or the other, but he is on a straight line to home plate. He mechanics look nearly flawless. You can see why he's had so much success. He can repeat that delivery consistently.
I thought he went at it a little harder today than the other day. The velocity was up. I was told he didn't really throw a splitter or a changeup in Japan, but I saw him throw a splitter in his bullpen session and a change and they had movement and good location. He's got a bunch of pitches and I think he's trying to see what may work and what won't.
He's an athlete and you have to like the build on him. He goes about his business.
The ability to consistently repeat his delivery is something that is critical for a major league pitcher who is expected to be a top of the rotation type starter. Repeating your delivery is key to being able to command your pitchers, and Cliff Lee ascendancy to elite #1 status was driven in large part by off-the-chart command that was the result of him mastering that repeatability.
If Darvish can show above-average command of his stuff, he seems likely to be a legit top of the rotation starter in the majors.
UPDATE -- Evan Grant also has a blog post on Darvish throwing today, which includes this comment from Mike Olt:
I've never seen anybody move the ball move like that