I think Merkin Valdez and J.D. Durbin make an interesting comparison.  Both are guys with great fastballs and solid second pitches (Valdez' change-up, Durbin's curve) that have had trouble mastering a 3rd pitch.  Both are former BA top 100 guys who have dropped from that level due to lack of performance at higher levels and injuries.  Lastly, they both may be better suited to the back-end of a bullpen rather than the back-end of a rotation.

Do you think either sticks as a starter?  If moved to the bullpen, can they become top closers?  8th-inning guys?

Who will have the better career?