Baseball Prospectus has an interesting article (subscription only) about what in the world happened to the Royals' Alex Gordon. The article doesn't reach any firm conclusions, but suggests that one possible reason Gordon hasn't set the world on fire is that he didn't receive enough development time in the minors.
I mention this here because the parallels between Gordon and Pedro Alvarez are pretty interesting. Like Alvarez, Gordon was selected with the second overall pick in the draft as a 21-year-old third baseman who had pretty much been the best thing ever in college. Like Alvarez, Gordon didn't play pro ball in the year he was drafted.
Instead, the Royals started him at Class AA Wichita the following year. There, he hit .327/.427/.588 for a full season, which didn't exactly dampen the Royals' enthusiasm for him, so they made him their starting third baseman the following year.
It hasn't worked out. Gordon hit .247/.314/.411 in his rookie year. The next season, he drew more walks but still didn't show the power you'd hope for from a second overall pick. This season, Gordon had hip surgery in April, went on the DL, and hasn't hit when he's even been available. It's certainly possible that his hip is the main reason he hasn't played well this year, but then he also didn't play all that well even before that.
It appears Gordon could have used more time in the minors, and we'd do well to consider that with Alvarez. His stint at Lynchburg raised plenty of questions about his ability to control the strike zone, but his play so far as Class AA Altoona (.326/.411/.560) closely resembles Gordon's Class AA line. The Pirates seem likely to resist the temptation to promote Alvarez straight to the majors next year, and I think they're right to do that. Gordon's example shows the potential hazards in moving a player like Alvarez up too quickly, and Alvarez could probably stand to have at least a couple months at Class AAA before he's called up.
Matt Wieters, another top college pick who got only one full year in the minors, did get a couple months at AAA at the beginning of this year and has been mediocre so far in the big leagues, so even that rather conservative promotion schedule might not be a panacea for Alvarez. But at least the Pirates will get an extra year of player control in the bargain, and they won't have to worry about whether they promoted Alvarez too quickly.