In response to southpaw777's comment:
In response to hill55's comment:
Will Middlebrooks has posted a sub-.275 on-base percentage and a sub-.700 OPS in 129 games since the trade of Kevin Youkilis in June 2012 (after a spectacular 40-game MLB debut). Projectiing a .310 OBP and an .800 OPS is highly optimistic. Middlebrooks probably is who he is.
You can cherry pick SSS of the bad stats all you want. I dont. I also choose to put things in context, not just look at numbers. All you numbers guys forget that theres a human element to the game.
If you look at his OBP throughout the MiL and MLB, you will see that .310 is far from "highly optomistic". Actually its pretty modest. Besides last years struggles, we have to take into consideration the broken wrist in 2012 and the broken ribs this year, he hasnt had an OBP below .325 in MLB or MiL since low A ball when he was 19.
Hes had close to, or over a 500SLG a few times. His power is obviously there. to expect a SLG between 470-500 or better is aslo far from highly optomistic.
In all fairness, the 129-game sample I cited (in a 169-game MLB career) is larger than any of the single-season samples you referenced.
Here is an interesting tool titled the Minor League Equivalency Calculator, although I can't vouch for its accuracy: