Originally Posted by Brutus
You're using the wrong comparisons. Show the numbers of those same guys at Hamilton's point in his minor league career. I bet you'll see a huge difference. It's very iffy to compare guys' Major League numbers, especially without regard to age and experience, to someone who's 20 years old and in AA.
You've already admitted that guys' walk rates do carry over relatively well. So casting a wide net and saying "guys with the power of Hamilton simply don't walk 10% of the time" isn't prudent. Hamilton isn't every single player of that skillset. His skillset suggests he does walk more. Some guys do have better plate discipline. Just because he doesn't hit for a lot of power doesn't mean he won't be able to carry a higher walk rate.
I don't know that his skillset does suggest he will walk more. While you are right that some guys DO have better plate discipline, pitchers aren't the same in the minors as they are in the Majors. Right now, Billy Hamilton is walking nearly as much as Joey Votto has since 2010 (14.1% for Billy, 15.3% for Joey). I guess it is possible, but it simply doesn't seem likely. Pitchers have reason to fear throwing strikes to a guy like Votto. They have very little reason to fear throwing strikes to Hamilton. Not only is he not going to truly punish your strikes, he also has mild contact problems.
As for the comparison, you are right. Unfortunately the minor leagues don't really have a good database to work with like the Majors do.