This may be surprisingly random, but there's no reason to believe the offense hasn't drastically underachieved this season. Here are how I expect the Royals players to perform this season, based on their past results and age (mixed with typical career progression). (This is more or less the Opening Day starting lineup, or roster)
C - John Buck
.250/.325/.470, 20 HR, 60 RBI (Underachieved significantly)
1B - Ryan Shealy
.260/.330/.420, 15 HR, 65 RBI (Underachieved DRAMATICALLY)
2B - Mark Grudzielanek
.275/.330/.400, 5 HR, 50 RBI (Overachieved slightly)
3B - Alex Gordon
.260/.340/.420, 18 HR, 70 RBI (Underachieved significantly)
SS - Tony Pena, Jr.
.240/.290/.350, 2 HR, 40 RBI (Overachieved slightly)
LF - Emil Brown
.265/.340/.450, 20 HR, 70 RBI (Underachieved significantly)
CF - David DeJesus
.290/.370/.430, 10 HR, 60 RBI (Underachieved slightly)
RF - Mark Teahen
.275/.380/.440, 15 HR, 75 RBI (Underachieved significantly)
DH - Mike Sweeney
.270/.350/.400, 15 HR, 70 RBI (Underachieved, alarming to see his refusal to take a walk the last two seasons)
C - Jason LaRue (Underachieved dramatically)
1B - Ross Gload (On-par)
2B - Esteban German (Underachieved slightly)
OF - Shane Costa (Underachieved slightly)
OF - Joey Gathright (Overachieved significantly)
OF - Reggie Sanders (Underachieved given injury)
OF - Billy Butler (Overachieved)
Those whose stats I gave are just our Opening Day guys, and yes some of that production has been offset by the surgent production of Joey Gathright and Billy Butler, who have probably performed above most fans' expectations this season. However, that production has even been offset by the "Debbie Downers" of Jason LaRue (who has been overplayed and has also underperformed) and Reggie Sanders (who has underperformed based on his injuries).
There's no question in my mind that Buddy Bell and hitting coach Mike Barnett's offensive philosophies have been a detriment to this ballclub this season. Their "hack, hack, hack" approach have caused our walk total to decrease dramatically, especially from our capabilities. That, in turn, has caused our OBP to dramatically decrease. Yes, we have players on our roster who are not typically known for drawing the walk: Tony Pena and Mark Grudzielanek included. However, there's still no doubt in my mind we have underachieved in that area.
That falls back to hitting coach Mike Barnett and, ultimately, Buddy Bell. My only worry is not that we have underachieved in the win column (as a result) this season, but that it may affect our young players in the future. The core of this team - Billy Butler, Mark Teahen, David DeJesus, Alex Gordon, and John Buck ALL included - needs to be patient and draw walks. Buddy and Barnett have hindered their progress in this area significantly this season.