Courtesy of a Keith Law tweet this morning:
Heyward's 67 BB are already the 6th-highest total ever for a player 20 or under. 16 more would put him 3rd behind Ted Williams and Mel Ott.
That's pretty amazing, and that's even with Heyward missing a month with injuries. We might all get frustrated with Jason for being a little too patient at times, but the man already knows the strike zone better than most hitters in the league.
Here's one other stat that I dug up:
And that, ladies and gentlemen, is one of the many differences between Jason Heyward and Jeff Francoeur.