Jonathan Stiever, RHP, CHW

The best pitcher in the White Sox system last season, what kind of future can we expect from Jonathan Siever? Bullpen or a starter?
Video courtesy of 2080 Baseball
  • Born: May 12, 1997
  • B/T: Right/Right
  • 6’2″, 205-lbs
  • Drafted by the Chicago White Sox in the 5th round of the 2018 MLB June Amateur Draft out of Indiana University Bloomington (Bloomington, IN).

The Numbers

His raw numbers are listed above courtesy of Let’s aggregate by year and then focus on the important numbers for minor leaguers:
Stiever had a nice start to his professional career in Rookie ball in 2018. The walks were a tad high, but the K% made up for it, and he had little trouble with batters, as seen in his WHIP.

In 2019, though the K% dropped, so did the walks, the velocity went up, and he had a very good year through two levels of A ball.
Let’s put the splits numbers into a spreadsheet so we can see how he did against both righties and lefties, as well as in A or in A +:
He got better as he reached Class A Advanced (A+)! Early in the season, his WHIP was not great, particularly against LHB. When he advanced to A+, his WHIP improved greatly. Meanwhile he got his strikeouts against everyone, and in face improved as he moved up. His walk rate was metronomically boring (but good boring!).
Looks even to me, how about you?
Yes, there it is visually what we saw in the spreadsheet just above: he held his own in A-ball, a little up, a little down, but then took off when he reached A+.

Looking in the Minor League Baseball Analyst book, we see that Stiever has four pitches in his arsenal:
He has a 3/4s cross-fire delivery with a plus fastball that sits mid-90s but which he can get up to 98 if he were to move to the pen. Scouts differ on his best secondary pitch, with some saying his curve is the best, while other say his slider is the one. His slider has a tight, two-plane movement, sitting about 10 mph slower than his FB. That curve also changes levels nicely.

Stiever was going to work on his changeup this year, but then he was shut down with forearm soreness.

The Scouts


“Forearm soreness”?

Can he get a good third pitch?

How will AA batters fare against him?


These college arms can move quickly once they have the pitches sorted out. Stiever could probably hold his own in a major league bullpen right now if he had to, that’s how good his fastball is. But the team wants him to develop a good third pitch, and they should push for that unless it becomes clear that it cannot happen. Too soon to make that sort of decision.

When minor league baseball starts up again, Stiever will have to chance to show if he really is the best pitching prospect in the White Sox system. He might very well turn out to be just that.