Pittsburgh Pirates organization discussion

I am now working on the Boston Red Sox prospect list. The next organization in line is the Pittsburgh Pirates, to be followed by the Houston Astros, Philadelphia Phillies, Chicago White Sox, Colorado Rockies, New York Yankees, and the Cincinnati Reds.

Use this thread to discuss the Pittsburgh Pirates farm system. Possible points for community discussion include, but are not limited to:

****Gregory Polanco: does he have a massive breakout season or is he a steady improvement type? Or will he fail to develop?

****Tyler Glasnow's ridiculously good K/IP ratios and low hit rate are extremely intriguing. How well is that going to translate to higher levels? Will the walks eat him up, or is his stuff so good that hitters won't be able to touch him even if he's giving up some walks?

****Who is the next young Pirate arm to break out? Mitch Keller?

****Give your power projection for Austin Meadows.

****As always, feel free to discuss sleepers, under-rated, and over-rated prospects to your heart's content.