Here is the first of a series of posts about Controversial Prospects who generate different opinions from different analysts.

Today we have Tyler Robertson of the Minnesota Twins. I gave him a Grade B+ in the 2008 Baseball Prospect Book and personally rank him as the best current Twins prospects. Others disagree.

Baseball America reportedly ranks him as the Twins fourth-best prospect behind Nick Blackburn, Joe Benson, and Wilson Ramos.

Kevin Goldstein at Baseball Prospectus also ranks him at fourth, behind Ben Revere, Anthony Swarzak, and Jeff Manship.

My current ratings for the Twins have Robertson at first, with the top five looking like this: Robertson, Swarzak, Revere, Manship, Glen Perkins. I suspect I'm higher on him than anyone else.

So what gives? Why does Robertson draw such mixed reviews? The problem isn't his statistics: he went 9-5, 2.29 with a 123/33 K/BB ratio in 103 innings. He allowed 87 hits and a .226 average against. He gave up just three homers and posted a 2.00 GO/AO ratio. He was 19 years old in a full-season league. Midwest League or not, those are strong numbers without any holes that I can see. Everything was above average or better. He's a big guy at 6-5, 220 pounds and still has some physical projectability.

The problem is the mixed scouting reports. Baseball America says his fastball was just 87-90 last year. He threw 90-92 in high school. Midwest League observers I spoke with say he was anywhere in the 88-92 range last year, which makes the BA numbers sound a bit pessimistic; I guess our sources are a bit different. He has good breaking stuff and throws strikes. The main bugaboo for scouts is his delivery, which is stiff, looks funny, and gives rise to fear about injuries. He's smoothed it out a bit, but given that he repeats it well, is his injury risk really any higher than it is for any other pitcher his age? I'm not convinced of that.

For me, Robertson is a low-end Grade B+ /borderline Grade B prospect based on his performance, his youth, and the fact that I think the delivery issue is a bit overblown. I considered moving him to regular Grade B in my final grade changes, but decided to stick with my original instincts. As for his rating in the Twins system, for me he is very close to Swarzak (who almost got a Grade B+). Revere could end up as a Grade B+ very soon and could push ahead of both of them if he continues to hit.

In any event, Robertson as a Grade B+ is an aggressive rating, but it's a risk I am comfortable taking.

Tomorrow we will discuss Jed Lowrie.