Every year we focus a lot on breakout candidates in the Pirates' system. There has certainly been no shortage of those stories, from the massive breakouts like Gregory Polanco and Tyler Glasnow, to the lower scale breakouts like Elias Diaz and JaCoby Jones. The term "breakout" is relative, so you can expand the meaning to cover pretty much any successful season you wanted.
Prior to the 2015 season, I wrote an article previewing the potential breakout candidates in the Pirates' system. Some of the guys did break out in their own way, such as Steven Brault, Jordan Luplow, and Chad Kuhl.