Coming into this season, the Royals had a farm system that was widely regarded as one of the strongest ever. This was mainly because the system appeared to be loaded with impact prospects at the top. They had five prospects in Baseball America's Top 20 and nine in the top 83. And here's how they're doing this year (BA ranking in parentheses):
Eric Hosmer (8) - Doing well (117 OPS+) as a rookie in the majors.
Mike Moustakas (9) - Slipped a little from previous year in AAA. Promoted anyway and appears overwhelmed in majors with an OPS+ of 40 in 164 ABs.
Wil Myers (10) - Moved from catcher to outfield. Having only decent season in AA as power hasn't shown up. Hitting 249/352/372.
John Lamb (18) - Had Tommy John surgery.
Mike Montgomery (19) - Struggling in AAA, largely due to control problems. Has 5.20 ERA and 1.49 WHIP.
Christian Colon (51) - Struggling in AA, hitting 254/326/346.
Danny Duffy (68) - Got off to good start in AAA. Promoted to majors after eight games and has struggled, with 5.08 ERA and 1.67 WHIP.
Jake Odorizzi (69) - Got mid-season promotion after pitching well in high A. Has struggled in AA, with 5.31 ERA and 1.44 WHIP. K rate is way down and HR rate is way up.
Chris Dwyer (83) - Struggling in AA, partly due to control problems. Has ERA of 5.77 and WHIP of 1.49.
Out of nine prospects, only one (Hosmer) is having an unequivocally good year. Several struggled after promotions. Myers is having a so-so year, Lamb is hurt, and Montgomery, Colon and Dwyer are just having bad years.
So, are the Royals' prospects just not that good? Or did the team suddenly become incompetent at development?
Or is it possible that four months' stats aren't really the full measure of a prospect?